Articles | Volume 20, issue 6
https://doi.org/10.5194/hess-20-2353-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/hess-20-2353-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
17 Jun 2016
Research article |
| 17 Jun 2016
A meta-analysis and statistical modelling of nitrates in groundwater at the African scale
Issoufou Ouedraogo
CORRESPONDING AUTHOR
Earth and Life Institute, Université catholique de Louvain, Croix
du Sud 2, Box 2, B-1348 Louvain-la-Neuve, Belgium
Marnik Vanclooster
Earth and Life Institute, Université catholique de Louvain, Croix
du Sud 2, Box 2, B-1348 Louvain-la-Neuve, Belgium
Related authors
Issoufou Ouedraogo and Marnik Vanclooster
Proc. IAHS, 384, 69–74, https://doi.org/10.5194/piahs-384-69-2021, https://doi.org/10.5194/piahs-384-69-2021, 2021
Short summary
Short summary
The results of the study have shed light on the pollution problem of groundwater at the pan-African scale. We demonstrated the unambiguous link between population density (urban areas, agricultural activity) and pollution of groundwater. We showed that the machine learning techniques are promising for modelling groundwater degradation at the African scale because of its ability to provide meaningful analysis of nonlinear and complex relationships such as those found in hydrogeological studies.
Elise Verstraeten, Alice Alonso, Louise Collier, and Marnik Vanclooster
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2024-173, https://doi.org/10.5194/hess-2024-173, 2024
Preprint under review for HESS
Short summary
Short summary
This study evaluates the effectiveness of Wallonia's sustainable nitrogen management program against groundwater nitrate contamination, 20 years post-implementation. We analysed nitrate concentration time series from 36 locations, finding a modest overall improvement and variability across sites. Results reveal interrelated controlling factors, with land use and aquifer characteristics being key. Lack of improvement may be due to a time lag before the impact of regulatory measures is observable.
Damien Delforge, Olivier de Viron, Marnik Vanclooster, Michel Van Camp, and Arnaud Watlet
Hydrol. Earth Syst. Sci., 26, 2181–2199, https://doi.org/10.5194/hess-26-2181-2022, https://doi.org/10.5194/hess-26-2181-2022, 2022
Short summary
Short summary
Causal inference methods (CIMs) aim at identifying causal links from temporal dependencies found in time-series data. Using both synthetic data and real-time series from a karst system, we study and discuss the potential of four CIMs to reveal hydrological connections between variables in hydrological systems. Despite the ever-present risk of spurious hydrological connections, our results highlight that the nonlinear and multivariate CIM has a substantially lower false-positive rate.
Issoufou Ouedraogo and Marnik Vanclooster
Proc. IAHS, 384, 69–74, https://doi.org/10.5194/piahs-384-69-2021, https://doi.org/10.5194/piahs-384-69-2021, 2021
Short summary
Short summary
The results of the study have shed light on the pollution problem of groundwater at the pan-African scale. We demonstrated the unambiguous link between population density (urban areas, agricultural activity) and pollution of groundwater. We showed that the machine learning techniques are promising for modelling groundwater degradation at the African scale because of its ability to provide meaningful analysis of nonlinear and complex relationships such as those found in hydrogeological studies.
José Luis Gabriel, Miguel Quemada, Diana Martín-Lammerding, and Marnik Vanclooster
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2018-372, https://doi.org/10.5194/hess-2018-372, 2018
Revised manuscript not accepted
Short summary
Short summary
Cover cropping enhance many agricultural services, but few studies are available on the long term effect on hydraulic properties. Soil water content was monitored daily in a 10-year field experiment and hydraulic properties were determined based on inverse calibration. Cover crop increased of the soil micro- and macro-porosity. Then, the expected cover crop competition for water can be compensated by an improvement of the water retention in the intermediate layers of the soil profile.
Jose Luis Gabriel, Miguel Quemada, Diana Martín-Lammerding, and Marnik Vanclooster
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2017-643, https://doi.org/10.5194/hess-2017-643, 2017
Manuscript not accepted for further review
Short summary
Short summary
Few studies are available allowing to evaluate the impact of cover cropping on the long term change of soil hydrologic functions, so we assessed the changes during a 10-year field experiment. This study shows that the expected cover crop competition for water with the main crop can be compensated by an improvement of the water retention in the intermediate layers of the soil profile, enhancing the hydrologic functions of agricultural soils in regions which often are constrained by water stress.
Natalia Fernández de Vera, Jean Beaujean, Pierre Jamin, David Caterina, Marnik Vanclooster, Alain Dassargues, Ofer Dahan, Frédéric Nguyen, and Serge Brouyère
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2016-79, https://doi.org/10.5194/hess-2016-79, 2016
Revised manuscript not accepted
Short summary
Short summary
Soil and groundwater remediation at industrial contaminated sites require suitable field instrumentation for subsurface characterization. The proposed method provides chemical, hydraulic information and images from the subsurface via customized sensors installed in boreholes. Their installation at a brownfield allows flow and transport characterization of water and contaminants across a heterogeneous subsurface. The results proof the effectiveness of the method for characterization purposes.
F. Wiaux, M. Vanclooster, and K. Van Oost
Biogeosciences, 12, 4637–4649, https://doi.org/10.5194/bg-12-4637-2015, https://doi.org/10.5194/bg-12-4637-2015, 2015
Short summary
Short summary
In this study, we highlight the role of soil physical conditions and gas transfer mechanisms and dynamics in the decomposition and storage of soil organic carbon in subsoil layers. To illustrate it, we measured the time series of soil temperature, moisture and CO2 concentration and calculated CO2 fluxes along 1 m depth soil profiles during 6 months throughout two contrasted soil profiles along a hillslope in the central loess belt of Belgium.
F. Meskini-Vishkaee, M. H. Mohammadi, and M. Vanclooster
Hydrol. Earth Syst. Sci., 18, 4053–4063, https://doi.org/10.5194/hess-18-4053-2014, https://doi.org/10.5194/hess-18-4053-2014, 2014
H. Sellami, I. La Jeunesse, S. Benabdallah, N. Baghdadi, and M. Vanclooster
Hydrol. Earth Syst. Sci., 18, 2393–2413, https://doi.org/10.5194/hess-18-2393-2014, https://doi.org/10.5194/hess-18-2393-2014, 2014
A. P. Tran, M. Vanclooster, and S. Lambot
Hydrol. Earth Syst. Sci., 17, 2543–2556, https://doi.org/10.5194/hess-17-2543-2013, https://doi.org/10.5194/hess-17-2543-2013, 2013
J. Minet, N. E. C. Verhoest, S. Lambot, and M. Vanclooster
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hessd-10-4063-2013, https://doi.org/10.5194/hessd-10-4063-2013, 2013
Revised manuscript has not been submitted
Related subject area
Subject: Water Resources Management | Techniques and Approaches: Modelling approaches
A generalised ecohydrological landscape classification for assessing ecosystem risk in Australia due to an altering water regime
Process-based three-layer synergistic optimal-allocation model for complex water resource systems considering reclaimed water
Joint optimal operation of the South-to-North Water Diversion Project considering the evenness of water deficit
Employing the generalized Pareto distribution to analyze extreme rainfall events on consecutive rainy days in Thailand's Chi watershed: implications for flood management
Leveraging a Novel Hybrid Ensemble and Optimal Interpolation Approach for Enhanced Streamflow and Flood Prediction
How to account for irrigation withdrawals in a watershed model
Inferring reservoir filling strategies under limited-data-availability conditions using hydrological modeling and Earth observations: the case of the Grand Ethiopian Renaissance Dam (GERD)
Climate-change impact on reservoir evaporation and water availability in a tropical sub-humid region, north-eastern Brazil
How economically and environmentally viable are multiple dams in the Upper Cauvery basin, India? A hydro-economic analysis using a landscape-based hydrological model
The H2Ours game to explore Water Use, Resources and Sustainability: connecting issues in two landscapes in Indonesia
The precision of satellite-based net irrigation quantification in the Indus and Ganges basins
Developing a Bayesian network model for understanding river catchment resilience under future change scenarios
Quantifying the trade-offs in re-operating dams for the environment in the Lower Volta River
Dynamically coupling system dynamics and SWAT+ models using Tinamït: application of modular tools for coupled human–water system models
Drainage assessment of irrigation districts: on the precision and accuracy of four parsimonious models
Development of an integrated socio-hydrological modeling framework for assessing the impacts of shelter location arrangement and human behaviors on flood evacuation processes
Cooperation in a transboundary river basin: a large-scale socio-hydrological model of the Eastern Nile
Flexible forecast value metric suitable for a wide range of decisions: application using probabilistic subseasonal streamflow forecasts
An improved model of shade-affected stream temperature in Soil & Water Assessment Tool
Seasonal forecasting of snow resources at Alpine sites
Operationalizing equity in multipurpose water systems
Evaluation of a new observationally based channel parameterization for the National Water Model
High-resolution drought simulations and comparison to soil moisture observations in Germany
Cooperation under conflict: participatory hydrological modeling for science policy dialogues for the Aculeo Lake
Socio-hydrological modeling of the tradeoff between flood control and hydropower provided by the Columbia River Treaty
Challenges and benefits of quantifying irrigation through the assimilation of Sentinel-1 backscatter observations into Noah-MP
A system dynamic model to quantify the impacts of water resources allocation on water–energy–food–society (WEFS) nexus
Net irrigation requirement under different climate scenarios using AquaCrop over Europe
The role of multi-criteria decision analysis in a transdisciplinary process: co-developing a flood forecasting system in western Africa
Unfolding the relationship between seasonal forecast skill and value in hydropower production: a global analysis
Drought impact links to meteorological drought indicators and predictability in Spain
Opportunities for seasonal forecasting to support water management outside the tropics
Probabilistic modelling of the inherent field-level pesticide pollution risk in a small drinking water catchment using spatial Bayesian belief networks
Are maps of nitrate reduction in groundwater altered by climate and land use changes?
Historical simulation of maize water footprints with a new global gridded crop model ACEA
Future upstream water consumption and its impact on downstream water availability in the transboundary Indus Basin
Identifying the dynamic evolution and feedback process of water resources nexus system considering socioeconomic development, ecological protection, and food security: A practical tool for sustainable water use
Optimizing a backscatter forward operator using Sentinel-1 data over irrigated land
Robustness of a parsimonious subsurface drainage model at the French national scale
Spatially distributed impacts of climate change and groundwater demand on the water resources in a wadi system
Delineation of dew formation zones in Iran using long-term model simulations and cluster analysis
Streamflow estimation at partially gaged sites using multiple-dependence conditions via vine copulas
Water resources management and dynamic changes in water politics in the transboundary river basins of Central Asia
Assessing interannual variability in nitrogen sourcing and retention through hybrid Bayesian watershed modeling
Minimizing the impact of vacating instream storage of a multi-reservoir system: a trade-off study of water supply and empty flushing
Global cotton production under climate change – Implications for yield and water consumption
Signatures of human intervention – or not? Downstream intensification of hydrological drought along a large Central Asian river: the individual roles of climate variability and land use change
Field-scale soil moisture bridges the spatial-scale gap between drought monitoring and agricultural yields
Socio-hydrologic modeling of the dynamics of cooperation in the transboundary Lancang–Mekong River
Multi-level storylines for participatory modeling – involving marginalized communities in Tz'olöj Ya', Mayan Guatemala
Alexander Herr, Linda E. Merrin, Patrick J. Mitchell, Anthony P. O'Grady, Kate L. Holland, Richard E. Mount, David A. Post, Chris R. Pavey, and Ashley D. Sparrow
Hydrol. Earth Syst. Sci., 28, 1957–1979, https://doi.org/10.5194/hess-28-1957-2024, https://doi.org/10.5194/hess-28-1957-2024, 2024
Short summary
Short summary
We develop an ecohydrological classification for regions with limited hydrological records. It provides causal links of landscape features and their water requirement. The classification is an essential framework for modelling the impact of future coal resource developments via water on the features. A rule set combines diverse data with prioritisation, resulting in a transparent, repeatable and adjustable approach. We show examples of linking ecohydrology with environmental impacts.
Jing Liu, Yue-Ping Xu, Wei Zhang, Shiwu Wang, and Siwei Chen
Hydrol. Earth Syst. Sci., 28, 1325–1350, https://doi.org/10.5194/hess-28-1325-2024, https://doi.org/10.5194/hess-28-1325-2024, 2024
Short summary
Short summary
Applying optimal water allocation models to simultaneously enable economic benefits, water preferences, and environmental demands at different decision levels, timescales, and regions is a challenge. In this study, a process-based three-layer synergistic optimal-allocation model (PTSOA) is established to achieve these goals. Reused, reclaimed water is also coupled to capture environmentally friendly solutions. Network analysis was introduced to reduce competition among different stakeholders.
Bing-Yi Zhou, Guo-Hua Fang, Xin Li, Jian Zhou, and Hua-Yu Zhong
Hydrol. Earth Syst. Sci., 28, 817–832, https://doi.org/10.5194/hess-28-817-2024, https://doi.org/10.5194/hess-28-817-2024, 2024
Short summary
Short summary
The current unreasonable inter-basin water transfer operation leads to the problem of spatial and temporal imbalances in water allocation. This paper defines a water deficit evenness index and incorporates it into a joint optimization model for the Jiangsu section of the South-to-North Water Diversion Project considering ecology and economy. At the same time, the lake storage capacity performs well, and the water transfer efficiency of the river is significantly improved.
Tossapol Phoophiwfa, Prapawan Chomphuwiset, Thanawan Prahadchai, Jeong-Soo Park, Arthit Apichottanakul, Watchara Theppang, and Piyapatr Busababodhin
Hydrol. Earth Syst. Sci., 28, 801–816, https://doi.org/10.5194/hess-28-801-2024, https://doi.org/10.5194/hess-28-801-2024, 2024
Short summary
Short summary
This study examines the impact of extreme rainfall events on flood risk management in Thailand's Chi watershed. By analyzing historical data, we identified regions, notably Udon Thani and Chaiyaphum, with a high risk of flash flooding. To aid in flood risk assessment, visual maps were created. The study underscores the importance of preparing for extreme rainfall events, particularly in the context of climate change, to effectively mitigate potential flood damage.
Mohamad El Gharamti, Arezoo RafieeiNasab, and James L. McCreight
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2023-269, https://doi.org/10.5194/hess-2023-269, 2024
Revised manuscript accepted for HESS
Short summary
Short summary
This study introduces a hybrid data assimilation scheme for precise streamflow predictions during intense rainfall and hurricanes. Tested in real events, it outperforms traditional methods by up to 50 %, utilizing ensemble and climatological background covariances. The adaptive algorithm ensures reliability with a small ensemble, offering improved forecasts up to 18 hours in advance, marking a significant advancement in flood prediction capabilities.
Elisabeth Brochet, Youen Grusson, Sabine Sauvage, Ludovic Lhuissier, and Valérie Demarez
Hydrol. Earth Syst. Sci., 28, 49–64, https://doi.org/10.5194/hess-28-49-2024, https://doi.org/10.5194/hess-28-49-2024, 2024
Short summary
Short summary
This study aims to take into account irrigation withdrawals in a watershed model. The model we used combines agriculture and hydrological modeling. Two different crop models were compared, the first based on air temperature and the second based on Sentinel-2 satellite data. Results show that including remote sensing data leads to better emergence dates. Both methods allow us to simulate the daily irrigation withdrawals and downstream flow with a good accuracy, especially during low-flow periods.
Awad M. Ali, Lieke A. Melsen, and Adriaan J. Teuling
Hydrol. Earth Syst. Sci., 27, 4057–4086, https://doi.org/10.5194/hess-27-4057-2023, https://doi.org/10.5194/hess-27-4057-2023, 2023
Short summary
Short summary
Using a new approach based on a combination of modeling and Earth observation, useful information about the filling of the Grand Ethiopian Renaissance Dam can be obtained with limited data and proper rainfall selection. While the monthly streamflow into Sudan has decreased significantly (1.2 × 109–5 × 109 m3) with respect to the non-dam scenario, the negative impact has been masked due to higher-than-average rainfall. We reveal that the dam will need 3–5 more years to complete filling.
Gláuber Pontes Rodrigues, Arlena Brosinsky, Ítalo Sampaio Rodrigues, George Leite Mamede, and José Carlos de Araújo
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2023-189, https://doi.org/10.5194/hess-2023-189, 2023
Revised manuscript accepted for HESS
Short summary
Short summary
The research focused in a four-million-inhabitants tropical region supplied by a network of open-water reservoirs whose dry season lasts 8 months (Jun−Dec). We analysed the impact of four climate change scenarios on the evaporation rate and the associated availability (water yield distributed per year). The worst-case scenario shows that by the end of the century (2071−2099) the evaporation rate in the dry season could increase by 6 %, which would reduce the stored water by about 80 %.
Anjana Ekka, Yong Jiang, Saket Pande, and Pieter van der Zaag
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2023-204, https://doi.org/10.5194/hess-2023-204, 2023
Revised manuscript accepted for HESS
Short summary
Short summary
For the first time we analyse the economic and ecological performances of existing multiple big reservoirs at daily time scale for a major river basin (Upper Cauvery) in India where pre-intervention data were not available but where there are increasing calls for such assessments. Results show that smaller reservoirs on smaller streams that maximize the economic value of water stored are better for the basin economy and the environment. The approach can help to prioritize dam removals.
Lisa Tanika, Rika Ratna Sari, Arief Lukman Hakim, Meine van Noordwijk, Marielos Peña-Claros, Beria Leimona, Edi Purwanto, and Erika N. Speelman
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2023-154, https://doi.org/10.5194/hess-2023-154, 2023
Preprint under review for HESS
Short summary
Short summary
The H2Ours game is designed to facilitate knowledge transfer and sharing among stakeholders to trigger commitments and collaborative actions to restore the hydrological conditions. The adaptability of H2Ours game was proven in two different landscapes: a groundwater recharge in upper-middle sub-watersheds with (over)use water in the lowlands zone, and a peatland with drainage-rewetting, oil palm conversion, and fire as issues. The game evaluation shows that the H2Ours game meets its purpose.
Søren J. Kragh, Rasmus Fensholt, Simon Stisen, and Julian Koch
Hydrol. Earth Syst. Sci., 27, 2463–2478, https://doi.org/10.5194/hess-27-2463-2023, https://doi.org/10.5194/hess-27-2463-2023, 2023
Short summary
Short summary
This study investigates the precision of irrigation estimates from a global hotspot of unsustainable irrigation practice, the Indus and Ganges basins. We show that irrigation water use can be estimated with high precision by comparing satellite and rainfed hydrological model estimates of evapotranspiration. We believe that our work can support sustainable water resource management, as it addresses the uncertainty of a key component of the water balance that remains challenging to quantify.
Kerr J. Adams, Christopher A. J. Macleod, Marc J. Metzger, Nicola Melville, Rachel C. Helliwell, Jim Pritchard, and Miriam Glendell
Hydrol. Earth Syst. Sci., 27, 2205–2225, https://doi.org/10.5194/hess-27-2205-2023, https://doi.org/10.5194/hess-27-2205-2023, 2023
Short summary
Short summary
We applied participatory methods to create a hybrid equation-based Bayesian network (BN) model to increase stakeholder understanding of catchment-scale resilience to the impacts of both climatic and socio-economic stressors to a 2050 time horizon. Our holistic systems-thinking approach enabled stakeholders to gain new perspectives on how future scenarios may influence their specific sectors and how their sector impacted other sectors and environmental conditions within the catchment system.
Afua Owusu, Jazmin Zatarain Salazar, Marloes Mul, Pieter van der Zaag, and Jill Slinger
Hydrol. Earth Syst. Sci., 27, 2001–2017, https://doi.org/10.5194/hess-27-2001-2023, https://doi.org/10.5194/hess-27-2001-2023, 2023
Short summary
Short summary
The construction of two dams in the Lower Volta River, Ghana, adversely affected downstream riverine ecosystems and communities. In contrast, Ghana has enjoyed vast economic benefits from the dams. Herein lies the challenge; there exists a trade-off between water for river ecosystems and water for anthropogenic water demands such hydropower. In this study, we quantify these trade-offs and show that there is room for providing environmental flows under current and future climatic conditions.
Joel Z. Harms, Julien J. Malard-Adam, Jan F. Adamowski, Ashutosh Sharma, and Albert Nkwasa
Hydrol. Earth Syst. Sci., 27, 1683–1693, https://doi.org/10.5194/hess-27-1683-2023, https://doi.org/10.5194/hess-27-1683-2023, 2023
Short summary
Short summary
To facilitate the meaningful participation of stakeholders in water management, model choice is crucial. We show how system dynamics models (SDMs), which are very visual and stakeholder-friendly, can be automatically combined with physically based hydrological models that may be more appropriate for modelling the water processes of a human–water system. This allows building participatory SDMs with stakeholders and delegating hydrological components to an external hydrological model.
Pierre Laluet, Luis Olivera-Guerra, Víctor Altés, Vincent Rivalland, Alexis Jeantet, Julien Tournebize, Omar Cenobio-Cruz, Anaïs Barella-Ortiz, Pere Quintana-Seguí, Josep M. Villar, and Olivier Merlin
EGUsphere, https://doi.org/10.5194/egusphere-2023-543, https://doi.org/10.5194/egusphere-2023-543, 2023
Short summary
Short summary
Monitoring agricultural drainage flow in irrigated areas is key to water and soil management. In this paper, four simple drainage models are evaluated on two irrigated sub-basins where drainage flow is measured daily. The evaluation of their precision shows that they simulate drainage very well when calibrated with drainage data, and that one of them is slightly better. The evaluation of their accuracy shows that only one model can provide rough drainage estimates without calibration data.
Erhu Du, Feng Wu, Hao Jiang, Naliang Guo, Yong Tian, and Chunmiao Zheng
Hydrol. Earth Syst. Sci., 27, 1607–1626, https://doi.org/10.5194/hess-27-1607-2023, https://doi.org/10.5194/hess-27-1607-2023, 2023
Short summary
Short summary
This study develops an integrated socio-hydrological modeling framework that can simulate the entire flood management processes, including flood inundation, flood management policies, public responses, and evacuation activities. The model is able to holistically examine flood evacuation performance under the joint impacts of hydrological conditions, management policies (i.e., shelter location distribution), and human behaviors (i.e., evacuation preparation time and route-searching strategy).
Mohammad Ghoreishi, Amin Elshorbagy, Saman Razavi, Günter Blöschl, Murugesu Sivapalan, and Ahmed Abdelkader
Hydrol. Earth Syst. Sci., 27, 1201–1219, https://doi.org/10.5194/hess-27-1201-2023, https://doi.org/10.5194/hess-27-1201-2023, 2023
Short summary
Short summary
The study proposes a quantitative model of the willingness to cooperate in the Eastern Nile River basin. Our results suggest that the 2008 food crisis may account for Sudan recovering its willingness to cooperate with Ethiopia. Long-term lack of trust among the riparian countries may have reduced basin-wide cooperation. The model can be used to explore the effects of changes in future dam operations and other management decisions on the emergence of basin cooperation.
Richard Laugesen, Mark Thyer, David McInerney, and Dmitri Kavetski
Hydrol. Earth Syst. Sci., 27, 873–893, https://doi.org/10.5194/hess-27-873-2023, https://doi.org/10.5194/hess-27-873-2023, 2023
Short summary
Short summary
Forecasts may be valuable for user decisions, but current practice to quantify it has critical limitations. This study introduces RUV (relative utility value, a new metric that can be tailored to specific decisions and decision-makers. It illustrates how critical this decision context is when evaluating forecast value. This study paves the way for agencies to tailor the evaluation of their services to customer decisions and researchers to study model improvements through the lens of user impact.
Efrain Noa-Yarasca, Meghna Babbar-Sebens, and Chris Jordan
Hydrol. Earth Syst. Sci., 27, 739–759, https://doi.org/10.5194/hess-27-739-2023, https://doi.org/10.5194/hess-27-739-2023, 2023
Short summary
Short summary
Riparian vegetation has been identified as a strategy to control rising stream temperatures by shading streams. Riparian vegetation is included within a sub-basin-scale hydrological model and evaluated for full and efficient restoration scenarios. Results showed average temperature reductions of 0.91 and 0.86 °C for full and efficient riparian restoration, respectively. Notwithstanding the similar benefits, efficient restoration was 14.4 % cheaper than full riparian vegetation restoration.
Silvia Terzago, Giulio Bongiovanni, and Jost von Hardenberg
Hydrol. Earth Syst. Sci., 27, 519–542, https://doi.org/10.5194/hess-27-519-2023, https://doi.org/10.5194/hess-27-519-2023, 2023
Short summary
Short summary
Reliable seasonal forecasts of the abundance of mountain snowpack over the winter/spring ahead provide valuable information for water management, hydropower production and ski tourism. We present a climate service prototype to generate multi-model ensemble seasonal forecasts of mountain snow depth, based on Copernicus seasonal forecast system meteorological data used to force the SNOWPACK model. The prototype shows skill at predicting snow depth below and above normal and extremely dry seasons.
Guang Yang, Matteo Giuliani, and Andrea Castelletti
Hydrol. Earth Syst. Sci., 27, 69–81, https://doi.org/10.5194/hess-27-69-2023, https://doi.org/10.5194/hess-27-69-2023, 2023
Short summary
Short summary
Participatory decision-making is a well-established approach to address the increasing pressure on water systems that searches for system-wise efficient solutions but often does not quantify how the resulting benefits are distributed across stakeholders. In this work, we show how including equity principles into the design of water system operations enriches the solution space by generating more compromise solutions that balance efficiency and justice.
Aaron Heldmyer, Ben Livneh, James McCreight, Laura Read, Joseph Kasprzyk, and Toby Minear
Hydrol. Earth Syst. Sci., 26, 6121–6136, https://doi.org/10.5194/hess-26-6121-2022, https://doi.org/10.5194/hess-26-6121-2022, 2022
Short summary
Short summary
Measurements of channel characteristics are important for accurate forecasting in the NOAA National Water Model (NWM) but are scarcely available. We seek to improve channel representativeness in the NWM by updating channel geometry and roughness parameters using a large, previously unpublished, dataset of approximately 48 000 gauges. We find that the updated channel parameterization from this new dataset leads to improvements in simulated streamflow performance and channel representation.
Friedrich Boeing, Oldrich Rakovec, Rohini Kumar, Luis Samaniego, Martin Schrön, Anke Hildebrandt, Corinna Rebmann, Stephan Thober, Sebastian Müller, Steffen Zacharias, Heye Bogena, Katrin Schneider, Ralf Kiese, Sabine Attinger, and Andreas Marx
Hydrol. Earth Syst. Sci., 26, 5137–5161, https://doi.org/10.5194/hess-26-5137-2022, https://doi.org/10.5194/hess-26-5137-2022, 2022
Short summary
Short summary
In this paper, we deliver an evaluation of the second generation operational German drought monitor (https://www.ufz.de/duerremonitor) with a state-of-the-art compilation of observed soil moisture data from 40 locations and four different measurement methods in Germany. We show that the expressed stakeholder needs for higher resolution drought information at the one-kilometer scale can be met and that the agreement of simulated and observed soil moisture dynamics can be moderately improved.
Anahi Ocampo-Melgar, Pilar Barría, Cristián Chadwick, and Cesar Rivas
Hydrol. Earth Syst. Sci., 26, 5103–5118, https://doi.org/10.5194/hess-26-5103-2022, https://doi.org/10.5194/hess-26-5103-2022, 2022
Short summary
Short summary
This article examines how a hydrological model exploring the causes of a lake desiccation was turned into a 5-step participatory process to better adjust the model to address questions that were causing suspicions and conflicts in the community. Although the process was key in finding a combination of strategies that were of moderate impact and higher local acceptability, we address the challenges of such collaboration in modeling when conflict is deeply embedded in the context.
Ashish Shrestha, Felipe Augusto Arguello Souza, Samuel Park, Charlotte Cherry, Margaret Garcia, David J. Yu, and Eduardo Mario Mendiondo
Hydrol. Earth Syst. Sci., 26, 4893–4917, https://doi.org/10.5194/hess-26-4893-2022, https://doi.org/10.5194/hess-26-4893-2022, 2022
Short summary
Short summary
Equitable sharing of benefits is key to successful cooperation in transboundary water resource management. However, external changes can shift the split of benefits and shifts in the preferences regarding how an actor’s benefits compare to the other’s benefits. To understand how these changes can impact the robustness of cooperative agreements, we develop a socio-hydrological system dynamics model of the benefit sharing provision of the Columbia River Treaty and assess a series of scenarios.
Sara Modanesi, Christian Massari, Michel Bechtold, Hans Lievens, Angelica Tarpanelli, Luca Brocca, Luca Zappa, and Gabriëlle J. M. De Lannoy
Hydrol. Earth Syst. Sci., 26, 4685–4706, https://doi.org/10.5194/hess-26-4685-2022, https://doi.org/10.5194/hess-26-4685-2022, 2022
Short summary
Short summary
Given the crucial impact of irrigation practices on the water cycle, this study aims at estimating irrigation through the development of an innovative data assimilation system able to ingest high-resolution Sentinel-1 radar observations into the Noah-MP land surface model. The developed methodology has important implications for global water resource management and the comprehension of human impacts on the water cycle and identifies main challenges and outlooks for future research.
Yujie Zeng, Dedi Liu, Shenglian Guo, Lihua Xiong, Pan Liu, Jiabo Yin, and Zhenhui Wu
Hydrol. Earth Syst. Sci., 26, 3965–3988, https://doi.org/10.5194/hess-26-3965-2022, https://doi.org/10.5194/hess-26-3965-2022, 2022
Short summary
Short summary
The sustainability of the water–energy–food (WEF) nexus remains challenge, as interactions between WEF and human sensitivity and water resource allocation in water systems are often neglected. We incorporated human sensitivity and water resource allocation into a WEF nexus and assessed their impacts on the integrated system. This study can contribute to understanding the interactions across the water–energy–food–society nexus and improving the efficiency of resource management.
Louise Busschaert, Shannon de Roos, Wim Thiery, Dirk Raes, and Gabriëlle J. M. De Lannoy
Hydrol. Earth Syst. Sci., 26, 3731–3752, https://doi.org/10.5194/hess-26-3731-2022, https://doi.org/10.5194/hess-26-3731-2022, 2022
Short summary
Short summary
Increasing amounts of water are used for agriculture. Therefore, we looked into how irrigation requirements will evolve under a changing climate over Europe. Our results show that, by the end of the century and under high emissions, irrigation water will increase by 30 % on average compared to the year 2000. Also, the irrigation requirement is likely to vary more from 1 year to another. However, if emissions are mitigated, these effects are reduced.
Judit Lienert, Jafet C. M. Andersson, Daniel Hofmann, Francisco Silva Pinto, and Martijn Kuller
Hydrol. Earth Syst. Sci., 26, 2899–2922, https://doi.org/10.5194/hess-26-2899-2022, https://doi.org/10.5194/hess-26-2899-2022, 2022
Short summary
Short summary
Many western Africans encounter serious floods every year. The FANFAR project co-designed a pre-operational flood forecasting system (FEWS) with 50 key western African stakeholders. Participatory multi-criteria decision analysis (MCDA) helped prioritize a FEWS that meets their needs: it should provide accurate, clear, and timely flood risk information and work reliably in tough conditions. As a theoretical contribution, we propose an assessment framework for transdisciplinary hydrology research.
Donghoon Lee, Jia Yi Ng, Stefano Galelli, and Paul Block
Hydrol. Earth Syst. Sci., 26, 2431–2448, https://doi.org/10.5194/hess-26-2431-2022, https://doi.org/10.5194/hess-26-2431-2022, 2022
Short summary
Short summary
To fully realize the potential of seasonal streamflow forecasts in the hydropower industry, we need to understand the relationship between reservoir design specifications, forecast skill, and value. Here, we rely on realistic forecasts and simulated hydropower operations for 753 dams worldwide to unfold such relationship. Our analysis shows how forecast skill affects hydropower production, what type of dams are most likely to benefit from seasonal forecasts, and where these dams are located.
Herminia Torelló-Sentelles and Christian L. E. Franzke
Hydrol. Earth Syst. Sci., 26, 1821–1844, https://doi.org/10.5194/hess-26-1821-2022, https://doi.org/10.5194/hess-26-1821-2022, 2022
Short summary
Short summary
Drought affects many regions worldwide, and future climate projections imply that drought severity and frequency will increase. Hence, the impacts of drought on the environment and society will also increase considerably. Monitoring and early warning systems for drought rely on several indicators; however, assessments on how these indicators are linked to impacts are still lacking. Our results show that meteorological indices are best linked to impact occurrences.
Leah A. Jackson-Blake, François Clayer, Elvira de Eyto, Andrew S. French, María Dolores Frías, Daniel Mercado-Bettín, Tadhg Moore, Laura Puértolas, Russell Poole, Karsten Rinke, Muhammed Shikhani, Leon van der Linden, and Rafael Marcé
Hydrol. Earth Syst. Sci., 26, 1389–1406, https://doi.org/10.5194/hess-26-1389-2022, https://doi.org/10.5194/hess-26-1389-2022, 2022
Short summary
Short summary
We explore, together with stakeholders, whether seasonal forecasting of water quantity, quality, and ecology can help support water management at five case study sites, primarily in Europe. Reliable forecasting, a season in advance, has huge potential to improve decision-making. However, managers were reluctant to use the forecasts operationally. Key barriers were uncertainty and often poor historic performance. The importance of practical hands-on experience was also highlighted.
Mads Troldborg, Zisis Gagkas, Andy Vinten, Allan Lilly, and Miriam Glendell
Hydrol. Earth Syst. Sci., 26, 1261–1293, https://doi.org/10.5194/hess-26-1261-2022, https://doi.org/10.5194/hess-26-1261-2022, 2022
Short summary
Short summary
Pesticides continue to pose a threat to surface water quality worldwide. Here, we present a spatial Bayesian belief network (BBN) for assessing inherent pesticide risk to water quality. The BBN was applied in a small catchment with limited data to simulate the risk of five pesticides and evaluate the likely effectiveness of mitigation measures. The probabilistic graphical model combines diverse data and explicitly accounts for uncertainties, which are often ignored in pesticide risk assessments.
Ida Karlsson Seidenfaden, Torben Obel Sonnenborg, Jens Christian Refsgaard, Christen Duus Børgesen, Jørgen Eivind Olesen, and Dennis Trolle
Hydrol. Earth Syst. Sci., 26, 955–973, https://doi.org/10.5194/hess-26-955-2022, https://doi.org/10.5194/hess-26-955-2022, 2022
Short summary
Short summary
This study investigates how the spatial nitrate reduction in the subsurface may shift under changing climate and land use conditions. This change is investigated by comparing maps showing the spatial nitrate reduction in an agricultural catchment for current conditions, with maps generated for future projected climate and land use conditions. Results show that future climate flow paths may shift the catchment reduction noticeably, while implications of land use changes were less substantial.
Oleksandr Mialyk, Joep F. Schyns, Martijn J. Booij, and Rick J. Hogeboom
Hydrol. Earth Syst. Sci., 26, 923–940, https://doi.org/10.5194/hess-26-923-2022, https://doi.org/10.5194/hess-26-923-2022, 2022
Short summary
Short summary
As the global demand for crops is increasing, it is vital to understand spatial and temporal patterns of crop water footprints (WFs). Previous studies looked into spatial patterns but not into temporal ones. Here, we present a new process-based gridded crop model to simulate WFs and apply it for maize in 1986–2016. We show that despite the average unit WF reduction (−35 %), the global WF of maize production has increased (+50 %), which might harm ecosystems and human livelihoods in some regions.
Wouter J. Smolenaars, Sanita Dhaubanjar, Muhammad K. Jamil, Arthur Lutz, Walter Immerzeel, Fulco Ludwig, and Hester Biemans
Hydrol. Earth Syst. Sci., 26, 861–883, https://doi.org/10.5194/hess-26-861-2022, https://doi.org/10.5194/hess-26-861-2022, 2022
Short summary
Short summary
The arid plains of the lower Indus Basin rely heavily on the water provided by the mountainous upper Indus. Rapid population growth in the upper Indus is expected to increase the water that is consumed there. This will subsequently reduce the water that is available for the downstream plains, where the population and water demand are also expected to grow. In future, this may aggravate tensions over the division of water between the countries that share the Indus Basin.
Yaogeng Tan, Zengchuan Dong, Sandra M. Guzman, Xinkui Wang, and Wei Yan
Hydrol. Earth Syst. Sci., 25, 6495–6522, https://doi.org/10.5194/hess-25-6495-2021, https://doi.org/10.5194/hess-25-6495-2021, 2021
Short summary
Short summary
The rapid increase in economic development and urbanization is contributing to the imbalances and conflicts between water supply and demand and further deteriorates river ecological health, which intensifies their interactions and causes water unsustainability. This paper proposes a methodology for sustainable development of water resources, considering socioeconomic development, food safety, and ecological protection, and the dynamic interactions across those water users are further assessed.
Sara Modanesi, Christian Massari, Alexander Gruber, Hans Lievens, Angelica Tarpanelli, Renato Morbidelli, and Gabrielle J. M. De Lannoy
Hydrol. Earth Syst. Sci., 25, 6283–6307, https://doi.org/10.5194/hess-25-6283-2021, https://doi.org/10.5194/hess-25-6283-2021, 2021
Short summary
Short summary
Worldwide, the amount of water used for agricultural purposes is rising and the quantification of irrigation is becoming a crucial topic. Land surface models are not able to correctly simulate irrigation. Remote sensing observations offer an opportunity to fill this gap as they are directly affected by irrigation. We equipped a land surface model with an observation operator able to transform Sentinel-1 backscatter observations into realistic vegetation and soil states via data assimilation.
Alexis Jeantet, Hocine Henine, Cédric Chaumont, Lila Collet, Guillaume Thirel, and Julien Tournebize
Hydrol. Earth Syst. Sci., 25, 5447–5471, https://doi.org/10.5194/hess-25-5447-2021, https://doi.org/10.5194/hess-25-5447-2021, 2021
Short summary
Short summary
The hydrological subsurface drainage model SIDRA-RU is assessed at the French national scale, using a unique database representing the large majority of the French drained areas. The model is evaluated following its capacity to simulate the drainage discharge variability and the annual drained water balance. Eventually, the temporal robustness of SIDRA-RU is assessed to demonstrate the utility of this model as a long-term management tool.
Nariman Mahmoodi, Jens Kiesel, Paul D. Wagner, and Nicola Fohrer
Hydrol. Earth Syst. Sci., 25, 5065–5081, https://doi.org/10.5194/hess-25-5065-2021, https://doi.org/10.5194/hess-25-5065-2021, 2021
Short summary
Short summary
In this study, we assessed the sustainability of water resources in a wadi region with the help of a hydrologic model. Our assessment showed that the increases in groundwater demand and consumption exacerbate the negative impact of climate change on groundwater sustainability and hydrologic regime alteration. These alterations have severe consequences for a downstream wetland and its ecosystem. The approach may be applicable in other wadi regions with different climate and water use systems.
Nahid Atashi, Dariush Rahimi, Victoria A. Sinclair, Martha A. Zaidan, Anton Rusanen, Henri Vuollekoski, Markku Kulmala, Timo Vesala, and Tareq Hussein
Hydrol. Earth Syst. Sci., 25, 4719–4740, https://doi.org/10.5194/hess-25-4719-2021, https://doi.org/10.5194/hess-25-4719-2021, 2021
Short summary
Short summary
Dew formation potential during a long-term period (1979–2018) was assessed in Iran to identify dew formation zones and to investigate the impacts of long-term variation in meteorological parameters on dew formation. Six dew formation zones were identified based on cluster analysis of the time series of the simulated dew yield. The distribution of dew formation zones in Iran was closely aligned with topography and sources of moisture. The dew formation trend was significantly negative.
Kuk-Hyun Ahn
Hydrol. Earth Syst. Sci., 25, 4319–4333, https://doi.org/10.5194/hess-25-4319-2021, https://doi.org/10.5194/hess-25-4319-2021, 2021
Short summary
Short summary
This study proposes a multiple-dependence model for estimating streamflow at partially gaged sites. The evaluations are conducted on a case study of the eastern USA and show that the proposed model is suited for infilling missing values. The performance is further evaluated with six other infilling models. Results demonstrate that the proposed model produces more reliable streamflow estimates than the other approaches. The model can be applicable to other hydro-climatological variables.
Xuanxuan Wang, Yaning Chen, Zhi Li, Gonghuan Fang, Fei Wang, and Haichao Hao
Hydrol. Earth Syst. Sci., 25, 3281–3299, https://doi.org/10.5194/hess-25-3281-2021, https://doi.org/10.5194/hess-25-3281-2021, 2021
Short summary
Short summary
The growing water crisis in Central Asia and the complex water politics of the region's transboundary rivers are a hot topic for research, while the dynamic changes of water politics in Central Asia have yet to be studied in depth. Based on the Gini coefficient, water political events and social network analysis, we analyzed the matching degree between water and socio-economic elements and the dynamics of hydropolitics in transboundary river basins of Central Asia.
Jonathan W. Miller, Kimia Karimi, Arumugam Sankarasubramanian, and Daniel R. Obenour
Hydrol. Earth Syst. Sci., 25, 2789–2804, https://doi.org/10.5194/hess-25-2789-2021, https://doi.org/10.5194/hess-25-2789-2021, 2021
Short summary
Short summary
Within a watershed, nutrient export can vary greatly over time and space. In this study, we develop a model to leverage over 30 years of streamflow, precipitation, and nutrient sampling data to characterize nitrogen export from various livestock and land use types across a range of precipitation conditions. Modeling results reveal that urban lands developed before 1980 have remarkably high levels of nitrogen export, while agricultural export is most responsive to precipitation.
Chia-Wen Wu, Frederick N.-F. Chou, and Fong-Zuo Lee
Hydrol. Earth Syst. Sci., 25, 2063–2087, https://doi.org/10.5194/hess-25-2063-2021, https://doi.org/10.5194/hess-25-2063-2021, 2021
Short summary
Short summary
This paper promotes the feasibility of emptying instream storage through joint operation of multiple reservoirs. The trade-off between water supply and emptying reservoir storage and alleviating impacts on downstream environment are thoroughly discussed. Operation of reservoirs is optimized to calibrate the optimal parameters defining the activation and termination of emptying reservoir. The optimized strategy limits the water shortage and maximizes the expected benefits of emptying reservoir.
Yvonne Jans, Werner von Bloh, Sibyll Schaphoff, and Christoph Müller
Hydrol. Earth Syst. Sci., 25, 2027–2044, https://doi.org/10.5194/hess-25-2027-2021, https://doi.org/10.5194/hess-25-2027-2021, 2021
Short summary
Short summary
Growth of and irrigation water demand on cotton may be challenged by future climate change. To analyze the global cotton production and irrigation water consumption under spatially varying present and future climatic conditions, we use the global terrestrial biosphere model LPJmL. Our simulation results suggest that the beneficial effects of elevated [CO2] on cotton yields overcompensate yield losses from direct climate change impacts, i.e., without the beneficial effect of [CO2] fertilization.
Artemis Roodari, Markus Hrachowitz, Farzad Hassanpour, and Mostafa Yaghoobzadeh
Hydrol. Earth Syst. Sci., 25, 1943–1967, https://doi.org/10.5194/hess-25-1943-2021, https://doi.org/10.5194/hess-25-1943-2021, 2021
Short summary
Short summary
In a combined data analysis and modeling study in the transboundary Helmand River basin, we analyzed spatial patterns of drought and changes therein based on the drought indices as well as on absolute water deficits. Overall the results illustrate that flow deficits and the associated droughts clearly reflect the dynamic interplay between temporally varying regional differences in hydro-meteorological variables together with subtle and temporally varying effects linked to human intervention.
Noemi Vergopolan, Sitian Xiong, Lyndon Estes, Niko Wanders, Nathaniel W. Chaney, Eric F. Wood, Megan Konar, Kelly Caylor, Hylke E. Beck, Nicolas Gatti, Tom Evans, and Justin Sheffield
Hydrol. Earth Syst. Sci., 25, 1827–1847, https://doi.org/10.5194/hess-25-1827-2021, https://doi.org/10.5194/hess-25-1827-2021, 2021
Short summary
Short summary
Drought monitoring and yield prediction often rely on coarse-scale hydroclimate data or (infrequent) vegetation indexes that do not always indicate the conditions farmers face in the field. Consequently, decision-making based on these indices can often be disconnected from the farmer reality. Our study focuses on smallholder farming systems in data-sparse developing countries, and it shows how field-scale soil moisture can leverage and improve crop yield prediction and drought impact assessment.
You Lu, Fuqiang Tian, Liying Guo, Iolanda Borzì, Rupesh Patil, Jing Wei, Dengfeng Liu, Yongping Wei, David J. Yu, and Murugesu Sivapalan
Hydrol. Earth Syst. Sci., 25, 1883–1903, https://doi.org/10.5194/hess-25-1883-2021, https://doi.org/10.5194/hess-25-1883-2021, 2021
Short summary
Short summary
The upstream countries in the transboundary Lancang–Mekong basin build dams for hydropower, while downstream ones gain irrigation and fishery benefits. Dam operation changes the seasonality of runoff downstream, resulting in their concerns. Upstream countries may cooperate and change their regulations of dams to gain indirect political benefits. The socio-hydrological model couples hydrology, reservoir, economy, and cooperation and reproduces the phenomena, providing a useful model framework.
Jessica A. Bou Nassar, Julien J. Malard, Jan F. Adamowski, Marco Ramírez Ramírez, Wietske Medema, and Héctor Tuy
Hydrol. Earth Syst. Sci., 25, 1283–1306, https://doi.org/10.5194/hess-25-1283-2021, https://doi.org/10.5194/hess-25-1283-2021, 2021
Short summary
Short summary
Our research suggests a method that facilitates the inclusion of marginalized stakeholders in model-building activities to address problems in water resources. Our case study showed that knowledge produced by typically excluded stakeholders had significant and unique contributions to the outcome of the process. Moreover, our method facilitated the identification of relationships between societal, economic, and hydrological factors, and it fostered collaborations across different communities.
Cited articles
Abate, E. Y.: Anthropogenic Impacts on Groundwater Resources in the urban Environment of Dire Dawa, Ethiopia. Master Thesis in Geosciences, Department of Geosciences,Faculty of Mathematics and Natural Sciences, University of Oslo, 64 pp., 2010.
Abd El-Salam, M. M. and Abu-Zuid, G. I.: Impact of landfill leachate on the groundwater quality: A case study in Egypt, J. Adv. Res., 2014.
Abdalla, F. A. and Scheytt, T.: Hydrochemistry of surface water and groundwater from a fractured carbonate aquifer in the Helwan area, Egypt. J. Earth Syst. Sci., 121, 109–124, 2012.
Abdel-Lah, A. K. and Shamrukh, M.: Impact of septic system on ground water quality in a Nile valley village, Egypt. Sixth International Water Technology Conference, IWTC 2001, Alexandria, Egypt, 237–245, 2001.
Abdelbaki, C., Asnouni, F., Assoud, I., Cherif, Z. E. A., and Yahiaoui, I.: Contribution to the cartography of the groundwater quality of the urban group of Tlemcen (Algeria), Larhyss J., 16, 7–19, 2013.
Abdellah, A. M., Abdel-Magid, H. M., and Shommo, E. I.: Assessment of Groundwater Quality in Southern Suburb of the Omdurman City of Sudan, Greener J. Environ. Manage. Publ. Safety, 2, 83–90, 2013.
Abdesselam, S., Halitim, A., Jan, A., Trolard, F., and Bourrié, G.: Anthropogenic contamination of groundwater with nitrate in arid region: case study of southern Hodna (Algeria), Environ. Earth Sci., 70, 2129–2141, 2012.
Abenan, A. T., Jean, K. K., Bachir, S. M., Armand, A. K., Serge, D. K., Tanoh, K. J. J., Adiow, E. T., Kouassi, S. H., Jean-Patrice, J., and Jean, B.: Contribution of multicriteria analysis and GIS for the specific vulnerability mapping to agricultural inputs of groundwaters in Bonoua area (Southeast of Côte d'Ivoire), 2012.
Abou, M. M.: Pollution des eaux souterraines en milieu urban, cas de la nappe phréatique de la ville de Niamey, Institut Supérieur des Techniques de l'Eau, 112, 8 pp., 2000.
Ackah, M., Agyemang, O., Anim, A. K., Osei, J., Bentil, N. O., Kpattah, L., Gyamfi, E. T., and Hanson, J. E. K.: Assessment of groundwater quality for drinking and irrigation: the case study of Teiman-Oyarifa Community, Ga East Municipality, Ghana, Proc. Int. Acad. Ecol. Environ. Sci., 1, 186–194, 2011.
Adelekan, B. and Ogunde, O.: Quality of water from dug wells and the lagoon in Lagos Nigeria and associated health risks, Sci. Res. Essay., 7, 1195–1211, 2012.
Affum, A. O., Osae, S. D., Nyarko, B. J., Afful, S., Fianko, J. R., Akiti, T. T., Adomako, D., Acquaah, S. O., Dorleku, M., Antoh, E., Barnes, F., and Affum, E. A.: Total coliforms, arsenic and cadmium exposure through drinking water in the Western Region of Ghana: application of multivariate statistical technique to groundwater quality, Environ. Monit. Assess., 187, 4167, https://doi.org/10.1007/s10661-014-4167-x, 2015.
Aghzar, N., Berdai, H., Bellouti, A., and Soudi, B.: Pollution nitrique des eaux souterraines au Tadla (Maroc), J. Water Sci., 15, 459–492, 2002.
Ahmed, A. L. M., Sulaiman, S., Osman, M. M., Saeed, E. M., and Mohamed, Y. A.: Groundwater quality in Khartoum state, Sudan, J. Environ. Hydrol. 8, 7 pp., 2000.
Ahoussi, K. E., Youan, T. M., Loko, S., Adja, M. G., Lasm, T., and Jourda, J. P.: Étude hydrogéochimique des eaux des aquifères de fractures du socle Paléo-protérozoïque du Nord-Est de la Côte d'Ivoire: Cas de la région de Bondoukou, Afrique Sci., 8, 51–68, 2012.
Ake, G. E., Kouadio, H. B., Dongo, K., Dibi, B., Kouame, F. K., and Biemi, J.: Application des méthodes DRASTIC et SI pour l'étude de la vulnérabilité à la pollution par les nitrates (NO3−) de la nappe de Bonoua (Sud-Est dela Côte d'Ivoire), Int. J. Biol. Chem. Sci., 4, 1676–1692, 2010.
Akinbile, C. O.: Environmental Impact of Landfill on Groundwater Quality and Agricultural Soils in Nigeria, Soil Water Res., 7, 18–26, 2012.
Akoteyon, I. S. and Soladoye, O.: Groundwater Quality Assessment in Eti-Osa, Lagos-Nigeria using Multivariate Analysis, J. Appl. Sci. Environ. Manage., 15, 121–125, 2011.
Aladejana, J. A. and Talabi, A. O.: Assessment of Groundwater Quality in Abeokuta Southwestern, Nigeria, Int. J. Eng. Sci., 2, 21–31, 2013.
Alaoui, H. L., Oufdou, K., and Mezrioui, N.: Environmental pollutions impacts on the bacteriological and physicochemical quality of suburban and rural groundwater supplies in Marrakesh area (Morocco), Environ. Monit. Assess., 145, 195–207, 2008.
Aljazzar, T. H.: Adjustment of DRASTIC Vulnerability Index to Assess Groundwater Vulnerability for Nitrate Pollution Using the Advection-Diffusion Cell. Von der Fakultät für Georessourcen und Materialtechnik der Rheinisch-Westfälischen Technischen Hochschule Aachen, 146 pp., 2010.
Aller, L., Bennet, T., Lehr, J. H., and Petty, R. J.: DRASTIC: A standardized system for evaluating groundwater pollution using hydrological settings, Ada, OK, USA: Prepared by the National water Well Association for the US EPA Office of Research and Development, EPA/600/2-85-018, 163 pp., 1985.
Amini, M., Mueller, K., Abbaspour, K. C., Rosenberg, T., Afyuni, M., Møller, K. N., Sarr, M., and Johnson, C. A.: Statistical modeling of global geogenic fluoride contamination in groundwaters, Environ. Sci. Technol., 42, 3662–3668, 2008a.
Amini, M., Abbaspour, K. C., Berg, M., Winkel, L., Hug, S. J.., Hoehn, E., Yang, H., and Johnson, C. A.: Statistical modeling of global geogenic arsenic contamination in groundwater, Environ. Sci. Technol., 42, 3669–3675, 2008b.
Anane, M., Selmi, Y., Limam, A., Jedidi, N., and Jellali, S.: Does irrigation with reclaimed water significantly pollute shallow aquifer with nitrate and salinity? An assay in a perurban area in North Tunisia, Environ. Monit. Assess., 186, 4367–4390, 2014.
Angola Water Works: Annual Drinking Water Quality Report. IN5276001, http://www.angolain.org/Water/documents/Angola2013AnnualWaterReport.pdf (last access: 13 August 2014) 2 pp., 2013.
Ansa-Asare, O. D., Darko, H. F., and Asante, K. A.: Groundwater quality assessment of Akatsi, Adidome and Ho districts in the Volta Region of Ghana, Desalination, 248, 446–452, 2009.
Anthony, K.-O.: Impact of municipal solid wastes on underground water sources in Nigeria, Eur. Sci. J., 8, 19 pp., 2012.
Anuraga, T. S., Ruiz, L., Kumar, M. S. M., Sekhar, M., and Leijnse, A.: Estimating groundwater recharge using land use and soil data: A case study in South India, Agr. Water Manage. 84, 65–76, 2006.
Armah, F. A., Luginaah, I., and Benjamin, A.: Water Quality Index in the Tarkwa Gold Mining Area in Ghana, J. Transdiscipl. Environ. Stud., 11, 15 pp., 2012.
Armah, Y.: Hydrochemical Analysis of Groundwater In The Lower Pra Basin of Ghana, J. Water Resour. Protect., 2, 864–871, 2010.
Ascott, M. J., Wang, L., Stuart, M. E., Ward, R. S., and Hart, A.: Quantification of nitrate storage in the vadose (unsaturated) zone: a missing component of terrestrial N budgets, Hydrol. Process., 542, 694–705, https://doi.org/10.1002/hyp.10748, 2016.
Asslouj, J. E., Kholtei, S., Amrani-Paaza, N. E., and Hilali, A.: Impact des activités anthropiques sur la qualité des eaux souterraines de la communauté Mzamza (Chaouia, Maroc), Rev. Sci. Eau, 20, 309–321, 2007.
Ateawung, J. N.: A GIS-Based Water Balance Study of Africa. Master of Physical Land Resources, Universiteit Gent Vrije Universiteit Brussel Belgium., 55 pp., 2010.
Aza-Gnandji, C. D. R., Xu, Y., Raitt, L., and Levy, J.: Salinity of irrigation water in the Philippi farming area of the Cape Flats, Cape Town, South Africa, Water SA, 39, 199–210, 2013.
Bagalwa, M., Majaliwa, M., Mushagalusa, N., and Karume, K.: Estimation of Transported Pollutant Load from Small Urban Kahuwa River Micro-catchment in Lake Kivu, Democratic Republic of Congo, J. Environ. Sci. Eng., 2, 460–472, 2013.
Bahri, F. and Saibi, H.: Characterization, classification, bacteriological, and evaluation of groundwater from 24 wells in six departments of Algeria, Arab. J. Geosci. 5, 1449–1458, 2012.
Balogun, I. I., Akoteyon, I. S., and Adeaga, O.: Evaluating Land Use Effects on Groundwater Quality in Lagos-Nigeria Using Water Quality Index, J. Sci. Res., 4, 397–409, 2012.
Barhe, T. A. and Bouaka, F.: Physicochemical Characterization and Chlorination of Drilling Water Consumed In Brazzaville-Congo. Journal of Chemical, Biological and Physical Sciences, An International Peer Review E-3, J. Sci., 3, 2328–2336, 2013.
Batisani, N.: Groundwater hydrochemistry evaluation in rural Botswana: A contribution to integrated water resources management, Ethiop. J. Environ. Stud. Manage., (Suppl.1), 5, 521–528, https://doi.org/10.4314/ejesm.v5i4.S12, 2012.
Bauder, J. W., Sinclair, K. N., and Lund, R. E.: Physiographic and land use characteristics associated with nitrate nitrogen-nitrogen in montana groundwater, J. Environ. Qual., 22, 255–262, 1993.
Belghiti, M. L., Chahlaoui, A., Bengoumi, D., and El Moustaine, R.: Etude de la qualite physico-chimique et bacteriologique des eaux souterraines de la nappe plio-quaternaire dans la région de Meknès (Maroc), Larhyss J., 14, 21–36, 2013.
Belkhiri, L. and Mouni, L.: Hydrochemical analysis and evaluation of groundwater quality in El Eulma area, Algeria, Appl. Water Sci., 2, 127–133, 2012.
Ben Abbou, M., Fadil, F., El Haji, M., and Zemzami, M.: Impact anthropique sur la qualite des eaux souterraines du bassin versant de l'Oued Taza (Maroc), Eur. Sci. J., 10, 117–137, 2014.
Benabbou, A., Benhoussa, A., Fekhaoui, M., El blidi, S., El Abidi, A., and Bounagua, M.: Assessment the risk of impact of waste treatment center on groundwater quality in Oum Azza (Rabat, Morocco), J. Mater. Environ. Sci., 5, 143–152, 2014.
BGS (British Geological Survey): Groundwater Quality: Ghana. Report, 4 pp., 2000a.
BGS (British Geological Survey): Groundwater Quality: Tanzania. Report, 4 pp., 2000b.
BGS (British Geological Survey): Groundwater Quality: Ethiopia. Report, 6 pp., 2001a.
BGS (British Geological Survey): Groundwater Quality: Uganda. Report, 4 pp., 2001b.
BGS (British Geological Survey): Groundwater Quality: Burkina Faso, Report, 4 pp., 2002.
BGS (British Geological Survey): Groundwater Quality: Nigeria. Report, 9 pp., 2003a.
BGS (British Geological Survey): Groundwater Quality: Water Quality Fact Sheet: nitrate (Benin and Senegal). Produced for WaterAid. London: 6pp., 2003b.
Böhlke, J.-K.: Groundwater recharge and agricultural contamination, Hydrogeol. J., 10, 153–179, 2002.
Bonetto, S., De Luca Domenico, A., Fornaro, M., and Lasagna, M.: Drinking and irrigation groundwater quality in Bulbule and Zway area (Ethiopia). Proceedings of EWRA 2005, 6th International Conference, Menton, France, Paper EWRA129, 16 pp., 2005.
Bonsor, H. C. and MacDonald, A. M.: An initial estimate of depth to groundwater across Africa. British Geological Survey Open Report OR/11/067, 26 pp., 2011.
Bordalo, A. A. and Savva-Bordalo, J.: The quest for safe drinking water: an example from Guinea-Bissau (West Africa), Water Res., 41., 2978–2986, 2007.
Bossa, A. Y., Diekkrüger, B., Giertz, S., Steup, G., Sintondji, L. O., Agbossou, E. K. and Hiepe, C.: Modeling the effects of crop patterns and management scenarios on N and P loads to surface water and groundwater in a semi-humid catchment (West Africa), Agr. Water Manage., 115, 20–37, 2012.
Boy-Roura, M., Nolan, B. T., Menció, A., and Mas-Pla, J.: Regression model for aquifer vulnerability assessment of nitrate pollution in the Osona region (NE Spain), J. Hydrol., 505, 150–162, 2013.
Brandvold, V.: Nitrate Pollution of the Thiaroye Aquifer in the Suburban Parts of the Dakar Region, Senegal, Using Chemical and Stable Isotope Analyses to Identify the Sources of Nitrate and the Processes at the Groundwater/Surface Water Interface. Thesis of Norwegian University of Science and Technology, Department of Geology and Mineral Resources Engineering, 133 pp., 2013.
Bricha, S., Ounine, K., Oulkheir, S., El Haloui, N., and Attarassi, B.: Etude de la qualité physicochimique et bactériologique de la nappe phréatique M'nasra (Maroc), Afr. Sci., 3, 391–404, 2007.
Burow, K. R., Nolan, B. T., Rupert, M. G., and Dubrovsky, N. M.: Nitrate in groundwater of the United States, 1991–2003, Environ. Sci. Technol., 44, 4988–4997, 2010.
Burow, K. R., Jurgens, B. C., Belitz, K., and Dubrovsky, N. M.: Assessment of regional change in nitrate concentrations in groundwater in the Central Valley, California, USA, 1950s–2000s, Environ. Earth Sci., 69, 2609–2621, 2013.
Bushra, A. H.: Quantitative status, vulnerability and pollution of groundwater resources in different environmental and climatic contexts in Sardinia and in Ethiopia, PhD Thesis in Earth Science, 205 pp., 2011.
Charfi, S., Zouari, K., Feki, S., and Mami, E.: Study of variation in groundwater quality in a coastal aquifer in north-eastern Tunisia using multivariate factor analysis, Quat. Int., 302, 199–209, 2013.
Chippaux, J.-P., Houssier, S., Gross, P., Bouvier, C., and Brissaud, F.: Étude de la pollution de l'eau souterraine de la ville de Niamey, Niger, Bull. Soc. Pathol. Exot., 94, 119–123, 2002.
Close, M.: Critical Review of Contaminant Transport Time Through the Vadose Zone. Environment Canterbury Technical Report, Report No. R10/113, 46 pp., 2010.
Cobbina, S. J., Nyame, F. K., and Obiri, S.: Groundwater Quality in the Sahelian Region of Northern Ghana, West Africa, Res. J. Environ. Earth Sci., 4, 482–491, 2012.
Comte, J., Banton, O., Sambou, S., Travi, Y., and Ouedraogo, I.: L'aquifère des sables de la presqu'île de Dakar (Sénégal): état de la ressource et impacts anthropiques. Dix-huitièmes journées techniques du Comité Français d'Hydrogéologie de l'Association Internation des Hydrogélogues, Ressoources et gestion des aquifères littoraux, Cassis, 2012, 276–274, 2012.
Coplen, T. B., Herczeg, A. L., and Barnes, C.: Isotope engineering – using stable isotopes of the water molecule to solve practical problems. Environmental tracers in subsurface hydrology, Springer, 79–110, 2000.
Cronin, A. A., Pedley, S., Hoadley, A. W., Komou, F. K., Haldin, L. Gibson, J., and Breslin, N.: Urbanisation effects on groundwater chemical quality: findings focusing on the nitrate problem from 2 African cities reliant on on-site sanitation, J. Water Health, 5, 441–454, 2007.
Dale, M. R. T. and Fortin, M.-J.: Spatial autocorrelation and statistical tests in ecology, Ecoscience, 9, 162–167, 2002.
Dammo, M. N., Deborah, J. M., Yusuf, I. A., and Sangodoyin, A. Y.: Evaluation of ground water quality of konduga town, Nigeria. Europ. Int. J. Sci. Technol., 2, 13–20, 2013.
Dan-Hassan, M., Olasehinde, P., Amadi, A., Yisa, J., and Jacob, J.: Spatial and temporal distribution of nitrate pollution in groundwater of Abuja, Nigeria, Int. J. Chem., 4, p. 104, 2012.
Debernardi, L., and De-Luca, D. A., and Lasahna, M.: Correlation Between Nitrate Concentration in Groundwater and Parameters Affecting Aquifer Intrinsic Vulnerability, Environ. Geol., 55, 539–558, 2007.
Defourny, P., Kirches, G., Brockmann, C., Boettcher, M., Peters, M., Bontemps, S., et al.: Land cover CCI product user guide version 2, 2014.
De Witte, I.: Characterization of the status of Dar es Salaam aquifer in view of salt-water intrusion and nitrate contamination. Master in de Geologie,FAculteit Wetenschappen Vakgroep Geologie en Bodemkunde, Universiteit Gent, 141 pp., 2012.
Dibi, B., Konan-Waidhet, A. B., Konan F. K., Yao, C. S., Zilé, A. K., Savané, I., and Gnakri, D.: Characterization of the Origin of Pollutants in Groundwater from Biostatistical Tests: The Case of Catchment Ehania, South-Eastern Côte d'Ivoire, J. Water Resour. Protect., 5, 1178–1185, https://doi.org/10.4236/jwarp.2013.512125, 2013.
Diédhiou, M., Faye, S. C., Douf, O. C., Faye, S., Faye, A., Rev, V., Wohnlich, S., Wisotzky, F., Schulte, U., and Maloszewski, P.: Tracing groundwater nitrate sources in the Dakar suburban area: an isotopic multi-tracer approach, Hydrol. Process., 26, 760–770, 2012.
Djebebe-Ndjiguim, C. L., Huneau, F., Denis, A., Foto, E., Moloto-a-Kenguemba, G., Celle-Jeanton, H., Garel, E., Jaunat, J., Mabingui, J., and Le Coustumer, P.: Characterization of the aquifers of the Bangui urban area, Central African Republic, as an alternative drinking water supply resource, Hydrol. Sci. J., 58, 1760–1778, https://doi.org/10.1080/02626667.2013.826358, 2013.
Döll, P. and Fiedler, K.: Global-scale modeling of groundwater recharge, Hydrol. Earth Syst. Sci., 12, 863–885, https://doi.org/10.5194/hess-12-863-2008, 2008.
Douagui, A. G., Kouame, I. K., Koffi, K., Bi Goula, A. T., Dibi, B., Gone, D. L., Coulibaly, K., Seka, A. M., Kouassi, A. K., Oi Mangoua, J. M., and Savane, I.: Assessment of the bacteriological quality and nitrate pollution risk of Quaternary groundwater in the southern part of Abidjan District (Côte d'Ivoire), J. Hydro Environ. Res., 6, 227–238, https://doi.org/10.1016/j.jher.2012.05.001, 2012.
Drissa, S. T., Ernest, A. K., Marie-Solange, O. Y., Gbombélé, S., and Nagnin, S.: A Multivariate Statistical Analysis of Groundwater Chemistry Data in the Highest Bandama Basin at Tortiya (Northern Côte D'Ivoire), Earth Resour., 1, 72–77, https://doi.org/10.12966/er.09.03.2013, 2013.
Dungan, J. L., Perry, J. N., Dale, M. R. T., Legendre, P., Citron-Pousty, S., Fortin, M. J., Jakomulska, A., Miriti, M., and Rosenberg, M. S.: A balanced view of scale in spatial statistical analysis, Ecography, 25, 626–640, 2002.
Dzwairo, B., Hoko, Z., Love, D., and Guzha, E.: Assessment of the impacts of pit latrines on groundwater quality in rural areas: A case study from Marondera district, Zimbabwe, Phys. Chem. Earth, 31, 779–788, 2006.
Easa, A. and Abou-Rayan, A.: Domestic wastewater effect on the pollution of the groundwater in rural areas in Egypt. Fourteenth International Water Technology Conference, IWTC 14 2010, Cairo, Egypt, 909–923, 2010.
Eblin, S. G., Soro, G. M., Sombo, A. P., Aka, N., Kambiré, O., and Soro, N.: Hydrochimie des eaux souterraines de la région d'Adiaké (Sud-Est côtier de la Côte d' Ivoire), Larhyss J., 17, 193–214, 2014.
Eckhardt, D. A. V. and Stackelberg, P. E.: Relation of groundwater quality to land use on long Island, New York, Ground Water, 33, 1019–1033, https://doi.org/10.1111/j.1745-6584.1995.tb00047.x, 1995.
Edet, A., Nganje, T., Ukpong, A., and Ekwere, A.: Groundwater chemistry and quality of Nigeria: A status review, Afr. J. Environ. Sci. Technol., 5, 1152–1169, 2011.
Ekere, N. R.: Nitrates in rural communities water sources in Uzouwani, South eastern Nigeria, west Africa, J. Environ. Res. Develop., 7, 600–606, 2012.
El Bouqdaoui, K., Aachib, M., Blaghen, M. and Kholtei, S.: Modélisation de la pollution par les nitrates de la nappe de Berrechid, au Maroc, Afr. Sci., 5, 99–113, 2009.
El Hammoumi, N., Sinan, M., Lekhlif, B., and El Mahjoub, L.: Évaluation de la qualité des eaux souterraines pour l'utilisation dans l'eau potable et l'agriculture : plaine de Tadla, Maroc, Afr. Sci., 8, 54–66., 2012.
El Hammoumi, N., Naima, M., Lekhlif, B. and Lakhdar, M.: Use of multivariate statistical and geographic information system (GIS)-based approach to evaluate ground water quality in the irrigated plain of Tadla (Morocco), Int. J. Water Resour. Environ. Eng., 5, 77–93, 2013.
Engida, Z. A.: Groundwater study of Addis Ababa area, Report No. 01/93, 28 pp., 2001.
FAO-SWALIM: Hydrogeological Survey and Assessment of Selected Areas in Somaliland and Puntland. Technical Report No. W-20, FAO-SWALIM (GCP/SOM/049/EC) Project, Nairobi, Kenya, 2012.
Farjad, B., Mohamed, T., A., Wijesekara N., Pirasteh, S., and Shafri, H. Z. B. M.: Groundwater intrinsic vulnerability and risk mapping, Proc. ICE, 165, 441–450, 2012.
Fedrigoni, L., Krimissa, M., Zouari, K., Maliki, A., and Zuppi, G. M.: Origine de la minéralisation et comportement hydrogéochimique d'une nappe phréatique soumise à des contraintes naturelles et anthropiques sévères : exemple de la nappe de Djebeniana (Tunisie), C. R. Acad. Sci. Paris, Earth Planet. Sci., 332, 665–671, 2001.
Fekkoul, A., Zarhloule, Y., Boughriba, M. Machmachi, I., and Chafi, A.: Contamination par les pesticides organochloreset les nitrates des eaux souterraines du systeme aquifere de la plaine des Triffa (Maroc Nord Oriental), ScienceLib Editions Mersenne, 3, 110801, 2011.
Fetouani, S., Sbaa, M., Vanclooster, M., and Bendra, B.: Assessing ground water quality in the irrigated plain of Triffa (north-east Morocco), Agr. Water Manage., 95, 133–142, 2008.
Fianko, J. R., Osae, S., Adomako, D., and Achel, D. G.: Relationship between land use and groundwater quality in six districts in the eastern region of Ghana, Environ. Monit. Assess., 153, 139–146, 2009.
Focazio, M. J., Reilly, T. E., Rupert, M. G., and Helsel, D. R.: Assessing Ground-Water Vulnerability to Contamination: Providing Scientifically Defensible Information for Decision Makers, USGS Circular, 1224, 33 pp., 2002.
Foster, S. S. D. and Crease, R. I.: Nitrate pollution of Chalk groundwater in East Yorkshire – a hydrogeological appraisal, J. I. Water Eng., 28, 178–194, 1974.
Friedel, M. J.: Inventory and Review of Existing PRISM Hydrogeologic Data for the Islamic Republic of Mauritania, Africa: U.S. Geological Survey, Open-File Report 2008-1138, 69 pp., 2008.
Frind, E. O., Molson, J. W., and Rudolph, D. L.: Well vulnerability: a quantitative approach for source water protection, Ground Water, 44, 732–742, 2006.
Gardner, K. K. and Vogel, R. M.: Predicting Ground Water Nitrate Concentration from Land Use, Ground Water, 43, 343–352, 2005.
Gleeson, T., Moosdorf, N., Hartmann, J., and van Beek, L. P. H.: A glimpse beneath earth's surface: Global HYdrogeology MaPS (GLHYMPS) of permeability and porosity, Geophys. Res. Lett., 41, 3891–3898, 2014.
Greene, E. A., LaMotte, A. E., and Cullinan, K. A.: Ground-Water Vulnerability to Nitrate Contamination at Multiple Thresholds in the Mid-Atlantic Region Using Spatial Probability Models, Scientific Investigations Reports 2004-5118, 2004.
Grimason, A. M., Beattie, T. K., Masangwi, S. J., Jabu, G. C., Taulo, S. C., and Lungu, K. K.: Classification and quality of groundwater supplies in the Lower Shire Valley, Malawi – Part 2: Classification of borehole water supplies in Chikhwawa, Malawi, Water SA, 39, 573–582, https://doi.org/10.4314/wsa.v39i4.1, 2013.
Guideal, R., Bala, A. E., and Ikpokonte, E. A.: Physical and Chemical Quality of Groundwater in the Quaternary Aquifer in N'djamena Region, Chad Republic, J. Appl. Sci. Res., 6, 1885–1890, 2010.
Hall, M. D., Shaffer, M. J., Waskom, R. M., and Delgado, J. A: Regional nitrate leaching variability: what makes a difference in Northeastern Colorado, J. Am. Water Resour. Assoc., 37, 139–150, 2001.
Hamza, M. H., Added, A., Francés, A., and Rodríguez, R.: Validité de l'application des méthodes de vulnérabilité DRASTIC, SINTACS et SI à l'étude de la pollution par les nitrates dans la nappe phréatique de Metline-Ras Jebel-Raf Raf (Nord-Est tunisien), C. R. Geosci., 339, 493–505, 2007.
Hanson, C. R.: Nitrate concentrations in Canterbury ground water – A review of existing data, Report no. R02/17. Environment Canterbury, 2002.
Harbaugh, A. W., Banta, E. R., Hill, M. C., and McDonald, M. G.: MODFLOW-2000, The U.S. Geological Survey Modular Groundwater Model-User Guide to Modularization Concepts and the Groundwater and Flow process, Open-File Report 00-92, 121 pp., 2000.
Hartmann, J. and Moosdorf, N.: The new global lithological map database GLiM: A representation of rock properties at the Earth surface. Geochemistry, Geophysics, Geosystems, 13, Q12004, https://doi.org/10.29/2012GC004370, 2012.
Hassane, A. B.: Aquiferes superficiels et profonds et pollution urbaine en Afrique: cas de la communauté urbaine de Niamey (Niger). These de Doctorat, Université Abdou Moumouni de Niamey, 198 pp. and annexes, 2010.
Haylamicheal, D. and Moges, A.: Assessing water quality of rural water supply schemes as a measure of service delivery sustainability: A case study of WondoGenet district, Southern Ethiopia, Afr. J. Environ. Sci. Technol., 6, 229–236, 2012.
Helsel, D. R. and Hirsch, R. M.: Statistical Methods in Water Resources: Techniques of Water-Resources Investigations, Book 4, US Geological Survey, p. 522, Chapter A3, 1992.
Hengl, T., Hengl, T., de Jesus, J. M., MacMillan, R. A., Batjes, N. H., Heuvelink, G. B. M. Ribeiro, E., Samuel-Rosa, A., Kempen, B., Leenaars, J. G. B., Walsh, M. G., and Gonzalez, M. R.: SoilGrids1km – Global Soil Information Based on Automated Mapping. PLoS One, 9, e105992, https://doi.org/10.1371/journal.pone.0105992, 2014.
Hentati, I., Zaïri, M., and Ben Dhia, H.: A statistical and geographical information system analysis for groundwater intrinsic vulnerability: a validated case study from Sfax-Agareb, Tunisia, Water Environ. J. 25, 400–411, 2011.
Hosmer, D. W. and Lemeshow, S.: Applied Logistic Regression, John Wiley and Sons, New York, NY, 307 pp., 1989.
Idriss, H., Salih, I., and Sam, A. K.: Study of radon in ground water and physicochemical parameters in Khartoum state, J. Radioanal. Nucl. Chem., 290, 333–338, 2011.
Imoisi, O., Ayesanmi, A., and Uwumarongie-Ilori, E.: Assessment of groundwater quality in a typical urban settlement of resident close to three dumpsites in South-south, Nigeria, J. Environ. Sci. Water Resour. 1, 12–17, 2012.
Ishaku, J. M.: Assessment of groundwater quality index for Jimeta-Yola area, Northeastern Nigeria, J. Geol. Mining Res., 3, 219–231, 2011.
Kahssay, G., Olivier, J., Ayenew, T., and Ramose, M.: Low Cost Sanitation and its impact on Quality of Groundwater in Addis Ababa, 19 pp., 2010.
Kanyerere, T., Levy, J., Xu, Y., and Saka, J.: Assessment of microbial contamination of groundwater in upper Limphasa River catchment, located in a rural area of northern Malawi, Water SA, 38, 581–596, https://doi.org/10.4314/wsa.v38i4.14, 2012.
Kaown, D., Hyun, H., Bae, G.-O., and Lee, K.-K.: Factors affecting the spatial pattern of nitrate contamination in shallow groundwater, J. Geol. Mining Res., 36, 1479–1487, 2007.
Kashaigili, J. J.: Assessment of groundwater availability and its current and potential use and impacts in Tanzania, final report, International Water Management Institute (IWMI), 58 pp., 2010.
Keitt, T. H., Bjørnstad, O. N., Dixon, P. M., and Citron-Pousty, S.: Accounting for spatial pattern when modeling organism-environment interactions, Echography, 25, 616–625, 2002.
Ketata, M., Gueddari, M., and Bouhlila, R.: Use of geographical information system and water quality index to assess groundwater quality in El Khairat deep aquifer (Enfidha, Central East Tunisia), Arab. J. Geosci., 5, 1379–1390, 2011.
Kihumba, A. M., Longo, J. N., and Vanclooster, M.: Modelling nitrate pollution pressure using a multivariate statistical approach: the case of Kinshasa groundwater body, Democratic Republic of Congo, Hydrogeol. J., 1–13, 2015.
Kinniburgh, D. G., Gale, I. N., Gooddy, D. C., Darling, W. G., Marks, R. J., Gibbs, B. R., Coleby, L. M., Bird, M. J., and West, J. M.: Denitrification in the unsaturated zones of the British Chalk and Sherwood Sandstone aquifers, British Geological Survey Technical Report, UK, WD/99/2, British Geological Survey Technical Report WD/99/2, 1994.
Kissao, G. and Housséni, A.: Flooding and groundwater quality in a peripheral urban zone: the case of the district of Agoè-Zongo in Lomé, Togo. 4th AMMA International Conference, 2–6 July 2012, Toulouse, France, 23 pp., 2012.
Kleinbaum, D. G., Kupper, L. L., and Muller, K. E.: Applied regression analysis and other multivariate methods (2nd ed.), PWS Publishing Co., Boston, 366 pp., 1988.
Kleinbaum, D. G.: Logistic Regression, A Self-Learning Text, Springer-Verlag, Berlin, p. 282., 1994.
Knobeloch, L., Salna, B., Hogan, A., Postle, J., and Anderson, H.: Blue babies and nitrate-contaminated well water, Environmental Health Perspectives 108, 675–678, 2000.
Koklu, R., Sengorur, B., and Topal, B.: Water Quality Assessment Using Multivariate Statistical Methods – A Case Study: Melen River System (Turkey), Water Resour. Manage., 24, 959–978, 2009.
Kolpin, D. W.: Agricultural chemicals in groundwater of the Midwestern United States: relations to land use, J. Environ. Qual., 26, 1025–1037, 1997.
Kouame, K. J., Jourda, J. P., Saley, M. B., Deh, S. K., Anani, A. T., and Biémi, J.: Mapping of groundwater vulnerability zones to pollution in various hydrogeological environments of Côte d'Ivoire by DRASTIC method, Int. J. Sci. Eng. Res., 4, 915–923, 2013.
Kouassi, M. A., Yao, A. K., Ahoussi, E. K., Seki, C. L., Yao, A. N., Kouassi, I. K., and Biemi, J.: Apports des méthodes statistiques et hydrochimiques à la caractérisation des eaux des aquifères fissurés de la région du N'zi-Comoé (Centre-Est de la Côte d'Ivoire), Int. J. Biol. Chem. Sci., 4, 1816–1838, 2010.
Kouassi, M. A., Ahoussi, E. K., Koffi, B. Y., Ake, Y. A., and Biemi, J.: Caractérisation hydrogéochimique des eaux des aquifères fissurés de la zone Guiglo-Duekoué (Ouest de la Côte d'Ivoire), Int. J. Biol. Chem. Sci., 6, 504–518, 2012.
Kuitcha, D., Takounjou, A. L. F., and Ndjama, J.: Apport de l'hydrochimie et de l'isotope de l'environnement à la connaissance des ressources en eaux souterraines de Yaoundé, Cameroun, J. Appl. Biosci., 67, 5194–5208, 2013.
Kulabako, N., Nalubega, M., and Thunvik, R.: Study of the impact of land use and hydrogeological settings on the shallow groundwater quality in a peri-urban area of Kampala, Uganda, Sci. Total Environ., 381, 180–199, 2007.
Kyoung-Ho, K., Yun, S. T., Choi, B. Y., Chae, G. T., Joo, Y., Kim, K., and Kim, H.-S.: Hydrochemical and multivariate statistical interpretations of spatial controls of nitrate concentrations in a shallow alluvial aquifer around oxbow lakes (Osong area, central Korea), J. Contamin. Hydrol., 107, 114–127, 2009.
Labar, S., Hani, A., and Djabri, L.: Assessing groundwater contamination by hydrocarbons and heavy metals (Northeast of Algeria), J. Environ. Res. Manage., 3, 17–21, 2012a.
Labar, S., Hani, A., and Djabri, L.: Biochemical Approach to Assess Groundwater Pollution by Petroleum Hydrocarbons (Case Skikda Algeria), J. Water Resour. Protect., 4, 493–496, 2012b.
Ladekarl, U. L., Rasmussen, K. R., Christensen, S., Jensen, K. H., and Hansen, B.: Groundwater recharge and evapotranspiration for two natural ecosystems covered with oak and heather, J. Hydrol., 300, 76–99, 2005.
Laftouhi, N.-E., Vanclooster, M., Jalal, M., O. Witam, O., Aboufirassi, M., Bahir, M., and Persoons, É.: Groundwater nitrate pollution in the Essaouira Basin (Morocco), C. R. Geosci., 335, 307–317, 2003.
Lagnika, M., Ibikounle, M., Montcho, J. C., Wotto, V. D., and Sakiti, N. G.: Caractéristiques physico-chimiques de l'eau des puits dans la commune de Pobè (Bénin, Afrique de l'ouest), J. Appl. Biosci., 79, 6887, 2014.
Lamribah, A., Benajiba, M. H., Saoud, Y., Ahrikat, M., and Benzakour, M.: Impact de la pollution urbaine sur la contamination par les nitrates et les nitrites de la nappe phreatique de martil (Maroc), Larhyss J., 14, 79–91, 2013.
Laurent, M. and Marie, M. J.: Groundwater Quality of Southeastern Brazzaville, Congo, J. Chem., 7, 861–869, 2010.
Laurent, M., François, A., and Marie, M. J.: Assessment of groundwater quality during dry season in southeastern Brazzaville, Congo, Int. J. Appl. Biol. Pharmaceut. Technol., I, 762–769, 2010.
Legendre, P.: Spatial autocorrelation: trouble or new paradigm?, Ecology, 74, 1659–1673, 1993.
Legendre, P. and Fortin, M.-J.: Spatial pattern and ecological analysis, Vegetation, 80, 107–138., 1989.
Liu, C. W., Wang, Y. B., and Jang, C. S.: Probability-based nitrate contamination map of groundwater in Kinmen, Environ. Monit. Assess., 185, 10147–10156, 2013.
Loko, S., Ke, A., and Biemi, J.: Anthropogenic Activities and the Degradation of the Environmental Quality in Poor Neighborhoods of Abidjan, Côte d'Ivoire: Abia Koumassi Village, J. Environ. Protect., 4, 1099–1107, 2013a.
Loko, S., Ahoussi, K. E., Koffi, Y. B., Kakou, N. F., Kouassi, A. M., and Biemi, J.: Microbiological and physico-chemical quality of groundwater from artisanal sites of mining exploitation in the South-West of Côte d'Ivoire: case of the area of Hiré, Int. J. Sci. Eng. Res., 4, 567–574, 2013b.
Longo, J. N.: Apport des outls hydrogeochmiiques et i isotopques a la gestiion de laquiifere du mont Amba, Kinshasa/République Démocratique du Congo), Thèse en cotutelle internationale Academie d'aix marseille Universite d'Avignon et des Pays de Vaucluse, Universite de Kinshasa Faculte des Sciences Agronomiques, 203 pp., 2009.
MacDonald, A.: Groundwater, health, and livelihoods in Africa. British Geological Survey ©NERC 2010 Earthwise 26, 2 pp., 2010.
MacDonald, A. M., Bonsor, H. C., Dochartaigh, B. É. Ó., and Taylor, R. G.: Quantitative maps of groundwater resources in Africa, Environ. Res. Lett., 7, 024009, 1–7, 2012.
MacDonald, A. M., Taylor, R. G. and Bonsor, C. H. (Eds.): Groundwater in Africa – is there sufficient water to support the intensification of agriculture from “Land Grabs”, Handbook of land and water grabs in Africa, 376–383, 2013.
Madioune, D. H., Faye, S. C., and Faye, S.: Etude de la vulnerabilite intrinseque à la pollution de la nappe libre des sables quaternaires de thiaroye par la methode DRASTIC, J. Sci. Technol., 9, 1–11, 2011.
Maherry, A., Clarke, S., Tredoux, G., and Engelbrecht, P.: Spatial and temporal analysis of the nitrate concentrations in groundwater for South Africa, 12 pp., avaailable at: http://hdl.handle.net/10204/3848 (last access: 15 June 2016), 2009.
Mair, A. and El-Kadi, A. I.: Logistic regression modeling to assess groundwater vulnerability to contamination in Hawaii, USA, J. Contam. Hydrol., 153, 1–23, 2013.
Mande, S. A. S., Liu, M., Djaneye-Boundjou, G., Liu, F., Bawa, M. L., and Chen, H.: Nitrate in drinking water: A major polluting component of groundwater in gulf region aquifers, south of Togo, Int. J. Phys. Sci., 7, 144–152, 2012.
Masoud, A. A.: Spatio-temporal evaluation of the groundwater quality in Kafr Al-Zayat District, Egypt, Hydrol. Process., 27, 2987–3002, 2013.
Matini, L., Moutou, J. M., and Kongo-Mantono, M. S.: Evaluation hydro-chimique des eaux souterraines en milieu urbain au Sud-Ouest de Brazzaville, Congo, Afr. Sci., 5, 82–98, 2009.
Matini, L., Tathy, C., and Moutou, J. M.: Seasonal Groundwater Quality Variation in Brazzaville, Congo, Res. J. Chem. Sci., 2, 7–14, 2012.
Mattern, S. and Vanclooster, M: Estimating travel time of recharge water through the unsaturated zone using transfer function model, Environ. Fluid Mech., https://doi.org/10.1007/s10652-009-9148-1, 2009.
Mattern S., Fasbender, D., and Vanclooster, M.: Discriminating sources of nitrate pollution in a sandy aquifer, J. Hydrol., 376, 275–284, 2009.
Mattern, S., Raouafi, W., Bogaert, P., Fasbender, D., and Vanclooster, M.: Bayesian Data Fusion (BDF) of monitoring data with a statistical groundwater contamination model to map groundwater quality at the regional scale, J. Water Resour. Protect., 4, 929–943, https://doi.org/10.4236/jwarp.2012.411109, 2012.
Mbewe, S.: Characterisation and temporal variability assessment of groundwater quality in petauke town, Eastern province, Zambia. Master of Science in Integrated Water Resources Management, Department of Geology, School of Mines, University of Zambia. 134 pp., 2013.
McKenzie, J. M., Mark, B. G., Thompson, L. G., Schotterer, U., and Lin, P.-N.: A hydrogeochemical survey of Kilimanjaro (Tanzania): implications for water sources and ages, Hydrogeol. J., 18, 985–995, 2010.
Messameh, A., Benkhaled, A., and Achour, B.: Numerical Modelling of Groundwater Anthropic Pollution in Urban Area: Biskra City, Algeria, 13th International Conference on Urban Drainage, Sarawak, Malaysia, 7–12 September 2014, 6 pp., 2014.
Mjemah, I. C.: Saltwater Intrusion and Nitrate Pollution in the Coastal Aquifer of Dar es Salaam, International Workshop, Tanzania, Rome, 22 April 2013, 31 pp., 2013.
Mkandawire, T.: Quality of groundwater from shallow wells of selected villages in Blantyre District, Malawi, Phys. Chem. Earth, 33, 807–811, 2008.
Mpakam, H. G., Kenmogne, G. R. K., Tatiétsé, T. T., Maire, E., Boeglin, J.-l., Ekodeck, G. E., and Dupré, B.: Étude des facteurs de pollution des ressources en eau en milieu urbain: cas de Bafoussam (Ouest-Cameroun), 27 pp., 2009.
Mpenyana-Monyatsi, L. and Momba, M.: Assessment of groundwater quality in the rural areas of the North West Province, South Africa, Sci. Res. Essay., 7, 903–914, 2012.
Mtoni, Y., Mjemah, I. C., Bakundukize, C., Van Camp, M., Martens, K., and Walraevens, K.: Saltwater intrusion and nitrate pollution in the coastal aquifer of Dar es Salaam, Tanzania, Environ. Earth Sci., 70, 1091–1111, 2013.
Muiuane, E.: The Quality of Groundwater in and around Maputo city, Mozambique. Department of Geology, Eduardo Mondlane University http://www.waternetonline.ihe.nl/downloads/uploads/symposium/zambia2007/Water %20 and %20 Society/Muiuane.pdf (last access: 13 August 2014), 11 pp., 2007.
Musekiwa, C. and Majola, K.: Groundwater Vulnerability Map for South Africa, SA J. Geomatics2, 152–163, 2013.
Nachiyunde, K., Ikeda, H., Tanaka, K., and Kozaki, D.: Evaluation of portable water in five provinces of Zambia using a water pollution index, Afr. J. Environ. Sci. Technol., 7, 14–29, 2013.
Nair, G. A., Bohjuari, J. A., Al-Mariami, M. A., Attia, F. A., and El-Touml, F.: Groundwater quality of north-east Libya, J. Environ. Biol., 27, 695–700, 2006.
Napacho, Z. A. and Manyele, S. V.: Quality assessment of drinking water in Temeke District (part II): Characterization of chemical parameters, Afr. J. Environ. Sci. Technol., 4, 775–789, 2010.
Nedaw, D.: Water Balance and Groundwater Quality of Koraro Area, Tigray, Northern Ethiopia, MEJS, 2, 110–127, 2010.
Nelson, A.: African Population Database, UNEP GRID Sioux Falls, edited by: Nelson, A., African Population Database Documentation, retrieved on: 27 January 2011 from UNEP/GRID Sioux Falls, available at: http://www.arcgis.com/home/item.html?id=9ec46c83ca5c47ebb1a25bd43131b483 (last access: 18 March 2015), 2004.
Ngatcha, B. N. and Daira, D.: Nitrate pollution in groundwater in two selected areas from Cameroon and Chad in the Lake Chad basin, Water Pol., 12, 722–733, 2010.
Nkansah, M. A., Ofosuah, J., and Boakye, S.: Quality of groundwater in the Kwahu West district of Ghana, Am. J. Sci. Indust. Res., 1, 578–584, 2010.
Nolan, B. T.: Relating Nitrogen Sources and Aquifer Susceptibility to Nitrate in Shallow GroundWaters of the United States, US Geological Survey, 23 pp., 2001.
Nolan, B. T. and Hitt, K. J.: Vulnerability of shallow groundwater and drinking-water wells to nitrate in the United States, Environ. Sci. Technol., 40, 7834–7840, 2006.
Nolan, B. T., Hitt, K. J., and Ruddy, B. C.: Probability of Nitrate Contamination of Recently Recharged Groundwaters in the Conterminous, Environ. Sci. Technol., 36, 2138–2145, 2002.
Nolan, B. T., Gronberg, J. M., Faunt, C. C., Eberts, S. M., and Belitz, K.: Modeling nitrate at domestic and public-supply well depths in the Central Valley, California, Environ. Sci. Technol., 48, 5643–5651, 2014.
Nougang, M. E., Nola, M., Djuikom, E., Euphrasie, O. V., Moungang, L. M. and Bessa, H. A.: Abundance of Faecal Coliforms and Pathogenic E. coli Strains in Groundwater in the Coastal Zone of Cameroon (Central Africa), and Relationships with Some Abiotic Parameters, Curr. Res. J. Biol. Sci., 3, 622–632, 2011.
Nwankwoala, H. O. and Udom, G. J.: Hydrogeochemical evaluation of groundwater in parts of Eastern Niger Delta, Nigeria, J. Acad. Appl. Stud., 1, 33–58, 2011.
Nyarko, A. A.: Assessment of groundwater quality and urban water provision: A case of Taifa township in the Ga-east district of the greater Accra region, Ghana, MSc Environmental Science, Kwame Nkrumah University of Science and Technology (KNUST), 72 pp., 2008.
Obi, C. N. and George, P.: The Microbiological and Physico_chemical Analysis of Borehole waters used by Off-Campus Students of Michael Okpara University of Agriculture Umudite (MOUAU), Abia-State, Nigeria, Res. J. Biol. Sci., 6, 602–607, 2011.
Obinna, N. C., Ezeabasili, A. C. C., and Okoro, B. U.: Assessment of ground water quality in Awka, Anambra state, Nigeria, J. Environ. Sci. Water Resour., 3, 80–85, 2014.
Obuobie, E. and Barry, B.: Groundwater in sub-Saharan Africa: Implications for food security and livelihoods,Ghana Country Status on Groundwater, final report, 48 pp., 2010.
Ojuri, O. O. and Bankole, O. T.: Groundwater Vulnerability Assessment and Validation for a Fast Growing City in Africa: A Case Study of Lagos, Nigeria, J. Environ. Protect. 4, 454–465, 2013.
Olden, J. D., Lawler, J. T., and Poff, N. L.: Machine learning methods without tears: a primer for ecologists, Quart. Rev. Biol., 83, 171–193, 2008.
Oliveira, S., Oehler, F., San-Miguel-Ayanz, J., Camia, A., and Pereira, J. M. C.: Modeling spatial patterns of fire occurrence in Mediterranean Europe using Multiple Regression and Random Forest, Forest Ecol. Manag., 275, 117–129, 2012.
Omoboriowo, A. O., Chiaghanam, O. I., Soronnadi-Ononiwu, G. C., Acra, E. J., Okengwu, K. O., Ugwueze, C. U., Yikarebogha, Y., and Momta, P. S.: Appraisal of the Groundwater Quality in Arochukwu Area, Afikpo Basin, Nigeria, Int. J. Sci. Technol., 2, 788–793, 2012.
Ornguga, T. T.: Groundwater Quality Assessment and Sanitary Surveillance of Boreholes in Rural Areas in Benue State Of Nigeria, Acad. J. Interdisc. Stud., 3, 153–158, 2014.
Osemwegie, I., Oga, Y. M.-S., Ahoussi, K. E., Koffi, Y. B., Kouassi, A. M., and Biémi, J.: Influence of Anthropogenic Activities of Groundwater from Hand Dug Wells within the Precarious Settlements of Southern Abidjan, Côte d'Ivoire: Case of the Slums of Anoumabo (Marcory) and Adjouffou (Port-Bout), J. Water Resour. Protect., 5, 427–439, 2013.
Ouedraogo, I., Defourny, P., and Vanclooster, M.: Mapping the groundwater vulnerability for pollution at the pan-African scale, Sci. Total Environ., 544, 939–953, 2016.
Ouedraogo, I. and Vanclooster, M.: Shallow groundwater poses pollution problem for Africa, Sci. Dev. Net, 4 pp., 2016.
Pavelic, P., Giordano, M., Keraita, B., Ramesh, V. and Rao, T.: Eds. Groundwater availability and use in sub-saharan Africa: a review of 15 countries. Colombo, Sri Lanka: International Water Management Institute (IWMI), 274 pp., 2012.
Pineros-Garcet J. D., Ordonnez, A., Roosen, J., and Vanclooster, M.: Metamodelling: theory, concepts, and application to nitrate leaching modelling, Ecol. Model., 193, 629–644, 2006.
Potter, P., Ramankutty, N., Bennett, E. M., and Donner, S. D.: Characterizing the Spatial Patterns of Global Fertilizer Application and Manure Production, Earth Interact., 14, 1–22, 2010.
Prasad, A. M., Iverson, L. R., and Liaw, A.: Newer classification and regression tree techniques: bagging and random forests for ecological prediction, Ecosystems, 9, 181–199, 2006.
Rawlings, J. O., Pantula, S. G., and Dickey, D. A.: Applied regression analysis, a research tool, Springer, 658 pp., 1998.
R Development Core Team.: A language and environment for statistical computing, Vienna, R Fundation Statistical Computing, available at: http://www.r-project.org/ (last access: 21 January 2015), 2015.
Rim-Rukeh, A., Ikhifa, G. O., and Okokoyo, P. A.: Physico-chemical characteristics of some waters used for drinking and domestic purposes in the Niger Delta, Nigeria, Environ. Monit. Assess. 128, 475–482, 2007.
Rivett, M. O., Buss, S. R., Morgan, P., Smith, J. W. N., and Bemment, C. D.: Nitrate attenuation in groundwater: a review of biogeochemical controlling processes, Water Res., 42, 4215–4232, 2008.
Rosillon, F., Savadogo, B., Kabore, A., Bado-Sama, H. and Dianou, D.: Attempts to Answer on the Origin of the High Nitrates Concentrations in Groundwaters of the Sourou Valley in Burkina Faso, J. Water Resour. Protect., 4, 663–673, 2012.
Rouabhia, A., Baali, F., Hani, A., and Djabri, L.: Impact des activités anthropiques sur la qualité des eaux souterraines d'un aquifère en zone semi-aride: Cas de la plaine de la Merdja, Nord Est de l'Alégrie, Sécheresse, 20, 279–285, https://doi.org/10.1684/sec.2009.0199, 2009.
Rouabhia, A., Baali, F., and Fehdi, C.: Impact of agricultural activity and lithology on groundwater quality in the Merdja area, Tebessa, Algeria, Arab. J. Geosci., 3, 307-318, 2010.
Sadek, M. and El-Samie, A. S.: Pollution vulnerability of the Quaternary aquifer near Cairo, Egypt, as indicated by isotopes and hydrochemistry, Hydrogeol. J., 9, 273–281, 2001.
Saffigna, P. G. and Keeney, D. R.: Nitrate and Chloride in Groundwater under irrigated agriculture in Central Wisconsin, Groundwater, 15, 170–177, 1997.
Saidi, S., Bouri, S., and Ben Dhia, H.: Groundwater vulnerability and risk mapping of the Hajeb jelma aquifer (Central Tunisia) using a GIS-based DRASTIC model, Environ. Earth Sci., 59, 1579–1588, 2010.
Salem, M. A. and Alshergawi, M. I.: Physico-chemical Evaluation of Drinking Water Quality in Alshati District of Libya, IOSR J. Environ. Sci. Toxicol. Food Technol., 4, 41–51, 2013.
Salim, L. H. M., Elhassan, B. M., and Elawad, M. A.: Physicochemical Analysis of Surface and Ground Water in Karrary Locality, Sudan, Int. J. Sci. Eng. Technol. Res., 3, 436–438, 2014.
Sall, M. and Vanclooster, M.: Assessing the well water pollution problem by nitrates in the small scale farming systems of the Niayes region, Senegal, Agr. Water Manage., 96, 1360–1368, 2009.
Sanok, F. M., Toriman, M. E. B., and Mokhtar, M.: Evaluation of Spatial and Temporal Variation in North East Jabal Al Hasawna wellfields Water quality, Libya, Int. J. Adv. Agr. Environ. Eng., 1, 23–28, 2014.
Saruchera, D. and Lautze, J.: Measuring Transboundary Water Cooperation: Learning from the Past to Inform the Sustainable Development Goals, IWMI, Working Paper 168, 20 pp., 2015.
Sbargoud, S.: Validité de l'application de la méthode de vulnérabilité DRASTIC à l'étude de la pollution par les nitrates dans la Mitidja (Nord d'Algérie), Geotunis, 2013, 22 pp., 2013.
Secunda, S., Collin, M., and Melloul, A. J.: Groundwater vulnerability assessment using a composite model combining DRASTIC with extensive land use in Israel's Sharon region, J. Environ. Manage., 54, 39–57, 1998.
Seeber, K., Daïra, D., Bala, A. M. and Vassolo, S.: Lake Chad Basin: Sustainable Water Management, Groundwater Quality Investigations in the Lower Logone Floodplain in April–May 2013, 47 pp., techn_rep07, available at: http://www.cblt.org/en/bgr-report?order=title&sort=asc (last access: 3 September 2015), 2014.
Semar, A., Saibi, H., and Medjerab, A.: Contribution of multivariate statistical techniques in the hydrochemical evaluation of groundwater from the Ouargla phreatic aquifer in Algeria, Arab. J. Geosci., 6, 3427–3436, 2013.
Sharaky, A. M., Atta, S. A., El Hassanein, A. S., and Khallaf, K. M. A.: Hydrogeochemistry of groundwater in the western Nile Delta aquifers, Egypt. 2nd International Conference on the Geology of Tethys, 19–21 March 2007, Cairo University, 23 pp., 2007.
Showers, W. J., Genna, B., McDade, T., Bolich, R., and Fountain, J. C.: Nitrate contamination in groundwater on an urbanized dairy farm, Environ. Sci. Technol., 42, 4683–4688, 2008.
Smahi, D.: Environmental Impact of Casablanca Landfill on Groundwater Quality, Morocco, Int. J. Geosci., 4, 202–211, 2013.
Smida, H., Abdellaoui, C., Zairi, M., and Dhia, H. B.: Cartographie des zones vulnérables à la pollution agricole par la méthode DRASTIC couplée à un Système d'information géographique (SIG): cas de la nappe phréatique de Chaffar(sud de Sfax, Tunisie), Sécheresse, 21, 131–146, 2010.
Sophocleous, M.: GROUNDWATER RECHARGE, in Groundwater, edited by: Silveira, L., Wohnlich, S., and Usunoff, E. J., in Encyclopedia of Life Support Systems (EOLSS), Developed under the Auspices of the UNESCO, Eolss Publishers, Oxford, UK, available at: http://www.eolss.net (last access: 3 September 2015), 2004.
Sorichetta, A., Ballabio, C., Masetti, M., Robinson Jr., G. R., and Sterlacchini, S.: A comparison of data-driven groundwater vulnerability assessment methods, Ground Water, 51, 866–879, 2013.
Sorlini, S., Palazzini, D., Sieliechi, J., and Ngassoum, M.: Assessment of Physical-Chemical Drinking Water Quality in the Logone Valley (Chad-Cameroon), Sustainability, 5, 3060–3076, 2013.
Spalding, R. F. and Exner, M. E.: Occurrence of nitrate in groundwater – a review, J. Environ. Qual., 22, 392–402, 1993.
Stadler, S., Osenbrück, K., Knöller, K., Himmelsbach, T., Suckow, A., and Weise, S. M.: Origin of nitrate in groundwaters of Kalahari, Botswana. European Society for Isotope Research, Seggauberg, Austria, 27 June–1 July 2004, 3 pp., 2004.
Stadler, S., Osenbrück, K., Knöller, K., Suckow, A., Sültenfuß, J., Oster, H., Himmelsbach, T., and Hötzl, H.: Understanding the origin and fate of nitrate in groundwater of semi-arid environments, J. Arid Environ., 72, 1830–1842, 2008.
Stevenson, F. J. and Cole, M. A.: Cycles of Soil Carbon, Nitrogen, Phosphorus, Sulfur, Micronutrients (2nd ed.), John Wiley and Sons Inc., 448 pp., 1999.
Suthar, S., Bishnoi, P., Singh, S., Mutiyar, P. K., Nema, A. K., and Patil, N. S.: Nitrate contamination in groundwater of some rural areas of Rajasthan, India, J. Hazard Mater., 171, 189–199, 2009.
Tabue, Y. J. G., Feumba, R., Wethe, J., Ekodeck, G. E., and De, M. G.: Evaluation of Groundwater Suitability for Domestic and Irrigational Purposes: A Case Study from Mingoa River Basin, Yaounde, Cameroon, J. Water Resour. Protect., 4, 285–293, https://doi.org/10.4236/jwarp.2012.45031, 2012.
Tabue, Y. J. G., Ntamack, D., Feumba, R., Ngnikam, E., Wéthé, J., and Tanawa, É.: Vulnérabilité des eaux souterraines et périmètres de protection dans le bassin versant de la Mingoa (Yaoundé, Cameroun), Revue de l'Université de Moncton, 40, 71–96, 2009.
Tadesse, N., Bheemalingeswara, K., and Abdulaziz, M.: Hydrogeological Investigation and Groundwater Potential Assessment in Haromaya Watershed, Eastern Ethiopia, Mekelle University, 2, 26–48, 2010.
Tagma, T., Hsissou, Y., Bouchaou, L., Bouragba, L., and Boutaleb, S.: Groundwater nitrate pollution in Souss-Massa basin (south-west Morocco), Afr. J. Environ. Sci. Technol., 3, 301–309, 2009.
Taha, G. M. E. E.: Determination, Source Identification and GIS Mapping for Nitrate Concentration in Ground water from Bara Aquifer, B.Sc. Honor (Chemistry), Faculty of Science, University of Khartoum, 95 pp., 2010.
Talabi, A. O.: Geostatistical Assessment of Groundwater Quality from coastal aquifers of Igbokoda, Southwestern Nigeria. Journal Of Environmental Science, Toxicology And Food Technology (IOSR-JESTFT) 2, 18–24, 2012.
Tay, C. and Kortatsi, B.: Groundwater Quality Studies: A Case Study of the Densu Basin, Ghana, West Afr. J. Appl. Ecol., 12, 18 pp., 2008.
Tegegn, F. E.: Physico-chemical pollution pattern in Akaki River basin, Addis Ababa, Ethiopia. Master's thesis Physical Geography and Quaternary Geology, Stockholm University, 38 pp., 2012.
Temgoua, E.: Chemical and Bacteriological Analysis of Drinking Water from Alternative Sources in the Dschang Municipality, Cameroon, J. Environ. Protect., 2, 620–628, 2011.
Tesoriero, A. J. and Voss, F. D.: Predicting the probability of Elevated Nitrate Concentrations in the Puget Sound-Basin, Implications for Aquifer Susceptibility and Vulnerability, Ground Water, 35, 1029–1039, 1997.
Thayalakumaran, T., Charlesworth, P. B., Bristow, K. L., van Bemmelen, R. J., and Jaffres, J.: Nitrate and Ferrous Iron Concentration in the Lower Burdekin Aquifers: Assessing Denitrification Potential, SuperSoil 2004: 3rd Australian New Zealand Soils Conference, 5–9 December 2004, University of Sydney, Australia, 2004.
Tilahun, K. and Merkel, B. J.: Assessment of groundwater vulnerability to pollution in Dire Dawa, Ethiopia using DRASTIC, Environ. Earth Sci., 59, 1485–1496, 2010.
Todd Engineers and Kennedy/Jenks Consultants: Revised Final Groundwater Vulnerability Study Santa Clara County, California, Project Report, 92 pp., October 2010.
Totin, H. S. V., Boukari, M., Faye, S., Alassane, A., Orékan, V., and Boko, M.: Climate and Land Use Change Impacts on Groundwater Quality in the Beninese Coastal Basin of the Transboundary Aquifer System Benin-Nigeria-Togo. International Conference “Transboundary Aquifers: Challenges and New Directions” (ISARM2010), 6–8 December 2010, 4 pp., 2010.
Totin, H. S. V., Amoussou, E., Odoulami, L., Edorh, P. A., Boukari, M., and Boko, M.: Groundwater pollution and the safe water supply challenge in Cotonou town, Benin (West Africa), Proceedings of H04, IAHS-IAPSO-IASPEI Assembly, Gothenburg, Sweden, July 2013 IAHS Publ. 361, 191–196, 2013.
Trambauer, P., Dutra, E., Maskey, S., Werner, M., Pappenberger, F., van Beek, L. P. H., and Uhlenbrook, S.: Comparison of different evaporation estimates over the African continent, Hydrol. Earth Syst. Sci., 18, 193–212, https://doi.org/10.5194/hess-18-193-2014, 2014.
UNEP/DEWA.: Sanitation and Groundwater Protection – a UNEP Perspective UNEP/DEWA, http://www.bgr.bund.de/EN/Themen/Wasser/Veranstaltungen/symp_sanitatgwprotect/present_mmayi_pdf.pdf?__blob=publicationFile&v=2 (last access: 13 August 2014), 18 pp., 2014.
US EPA (Environmental Protection Agency): Environmental indicators of water quality in the United States: Washington, D.C., US Environmental Protection Agency, Office of Water, EPA 841-R-96-002, 25 pp., 1996.
Wakida, F. T. and Lerner, D. N.: Non-agricultural sources of groundwater nitrate: a review and case study, Water Res., 39, 3–16, 2005.
Wang, L., Stuart, M. E., Lewis, M. A., Ward, R. S., Skirvin, D., Naden, P. S., Collins, A. L., and Ascott, M.: The changing trend in nitrate concentrations in major aquifers due to historical nitrate loading from agricultural land across England and Wales from 1925 to 2150, Sci Total Environ., 542, 694–705, 2016.
Wheeler, D. C., Nolan, B. T., Flory, A. R., DellaValle, C. T., and Ward, M. H.: Modeling groundwater nitrate concentrations in private wells in Iowa, Sci. Total Environ., 536, 481–488, 2015.
Wiens, J. A.: Spatial scaling in ecology. Funct. Ecol., 3, 385–397, 1989.
Winkel, L., Berg, M., Amini, M., Hug, S. J., and Johnson, A. C.: Predicting groundwater arsenic contamination in Southeast Asia from surface parameters, Nature Geosci., 1, 536–542, 2008.
WHO (World Heath Organization): Rolling Revision of the WHO Guidelines for Drinking-Water Quality. Draft for review and comments, Nitrates and nitrites in drinking-water, WHO/SDE/WSH/04.08/56: 133 pp., 2004.
Worrall, F. and Besien, T.: The vulnerability of groundwater to pesticide contamination estimated directly from observations of presence or absence in wells, J. Hydrol., 303, 92–107, 2005.
Worrall, F., Howden, N. J. K., and Burt, T. P.: Evidence for nitrogen accumulation: the total nitrogen budget of the terrestrial biosphere of a lowland agricultural catchment, Biogeochemistry, 123, 411–428, https://doi.org/10.1007/s10533-015-0074-7, 2015.
Wotany, E. R., Ayonghe, S. N., Fantong, W. Y., Wirmvem, M. J., and Ohba, T.: Hydrogeochemical and anthropogenic influence on the quality of water sources in the Rio del Rey Basin, South Western, Cameroon, Gulf of Guinea, Afr. J. Environ. Sci. Technol., 7, 1053–1069, 2013.
Xu, Y. and Usher, B.: Groundwater pollution in Africa, Taylor&Francis/Balkema, the Netherlands, 353 pp., 2006.
Yang, C. Y., Cheng, M. F., Tsai, S. S., and Hsieh, Y. L.: Calcium, magnesium, and nitrate in drinking water and gastric cancer mortality, Cancer Sci., 89, 124–130, 1998.
Yao, T. K., Oga, M. S., Fouche, O., Baka, D., Pernelle, C., and Biemi, J.: Évaluation de la potabilité chimique des eaux souterraines dans un bassin versant tropical, Cas du Sud-Ouest de la Côte d'Ivoire, Int. J. Biol. Chem. Sci., 6, 7069–7086, 2013.
Young, C. P., Oakes, D. B., and Wilkinson, W. B.: Prediction of future nitrate concentrations in groundwater, Ground Water, 14, 426–438, 1976.
Zghibi, A., Tarhouni, J., and Zouhri, L.: Assessment of seawater intrusion and nitrate contamination on the groundwater quality in the Korba coastal plain of Cap-Bon (North-east of Tunisia), J. Afr. Earth Sci., 87, 1–12, 2013.
Zingoni, E., Love, D., Magadza,C., Moyce, W., and Musiwa, K.: Effects of a semi-formal urban settlement on groundwater quality, Phys. Chem. Earth, 30, 680–688, 2005.
Short summary
In this paper, we present a meta-analysis of nitrate contamination in groundwater at the pan-African scale. A nitrate data set is constructed based on publications in the web of sciences, and combined with high-resolution generic spatial environmental attributes. A statistical model explains 65 % of the variation of nitrate contamination in groundwater in terms of generic spatial attributes. Nitrate contamination of groundwater at the pan-African scale is mainly affected by population density.
In this paper, we present a meta-analysis of nitrate contamination in groundwater at the...
