Articles | Volume 20, issue 6
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 and Marnik Vanclooster
No articles found.
José Luis Gabriel, Miguel Quemada, Diana Martín-Lammerding, and Marnik Vanclooster
Hydrol. Earth Syst. Sci. Discuss.,
Revised manuscript not acceptedShort 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.,
Manuscript not accepted for further reviewShort 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.,
Revised manuscript not acceptedShort 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,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,
H. Sellami, I. La Jeunesse, S. Benabdallah, N. Baghdadi, and M. Vanclooster
Hydrol. Earth Syst. Sci., 18, 2393–2413,
A. P. Tran, M. Vanclooster, and S. Lambot
Hydrol. Earth Syst. Sci., 17, 2543–2556,
J. Minet, N. E. C. Verhoest, S. Lambot, and M. Vanclooster
Hydrol. Earth Syst. Sci. Discuss.,
Revised manuscript has not been submitted
Related subject area
Subject: Water Resources Management | Techniques and Approaches: Modelling approachesMinimizing the impact of vacating instream storage of a multi-reservoir system: a trade-off study of water supply and empty flushingGlobal cotton production under climate change – Implications for yield and water consumptionSignatures 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 changeField-scale soil moisture bridges the spatial-scale gap between drought monitoring and agricultural yieldsSocio-hydrologic modeling of the dynamics of cooperation in the transboundary Lancang–Mekong RiverMulti-level storylines for participatory modeling – involving marginalized communities in Tz'olöj Ya', Mayan GuatemalaBenchmarking an operational hydrological model for providing seasonal forecasts in SwedenImpact of the quality of hydrological forecasts on the management and revenue of hydroelectric reservoirs – a conceptual approachA novel causal structure-based framework for comparing a basin-wide water–energy–food–ecology nexus applied to the data-limited Amu Darya and Syr Darya river basinsProjection of irrigation water demand based on the simulation of synthetic crop coefficients and climate changeComparative analysis of kernel-based versus ANN and deep learning methods in monthly reference evapotranspiration estimationAssessing the value of seasonal hydrological forecasts for improving water resource management: insights from a pilot application in the UKFrom skill to value: isolating the influence of end user behavior on seasonal forecast assessmentThe value of citizen science for flood risk reduction: cost–benefit analysis of a citizen observatory in the Brenta-Bacchiglione catchmentRisk assessment in water resources planning under climate change at the Júcar River basinInterplay of changing irrigation technologies and water reuse: example from the upper Snake River basin, Idaho, USAThe benefit of using an ensemble of seasonal streamflow forecasts in water allocation decisionsEvapotranspiration partition using the multiple energy balance version of the ISBA-A-gs land surface model over two irrigated crops in a semi-arid Mediterranean region (Marrakech, Morocco)Irrigation return flow causing a nitrate hotspot and denitrification imprints in groundwater at Tinwald, New ZealandMulti-objective calibration by combination of stochastic and gradient-like parameter generation rules – the caRamel algorithmA novel data-driven analytical framework on hierarchical water allocation integrated with blue and virtual water transfersA novel regional irrigation water productivity model coupling irrigation- and drainage-driven soil hydrology and salinity dynamics and shallow groundwater movement in arid regions in ChinaAn evapotranspiration model self-calibrated from remotely sensed surface soil moisture, land surface temperature and vegetation cover fraction: application to disaggregated SMOS and MODIS dataOn the assimilation of environmental tracer observations for model-based decision supportInferred inflow forecast horizons guiding reservoir release decisions across the United StatesAssessment of potential implications of agricultural irrigation policy on surface water scarcity in BrazilAbility of a soil–vegetation–atmosphere transfer model and a two-source energy balance model to predict evapotranspiration for several crops and climate conditionsAssessing water security in the São Paulo metropolitan region under projected climate changeWHAT-IF: an open-source decision support tool for water infrastructure investment planning within the water–energy–food–climate nexusRepresentation and improved parameterization of reservoir operation in hydrological and land-surface modelsWater restrictions under climate change: a Rhône–Mediterranean perspective combining bottom-up and top-down approachesQuantifying thermal refugia connectivity by combining temperature modeling, distributed temperature sensing, and thermal infrared imagingReconstructed natural runoff helps to quantify the relationship between upstream water use and downstream water scarcity in China's river basinsCan global precipitation datasets benefit the estimation of the area to be cropped in irrigated agriculture?Seasonal drought prediction for semiarid northeast Brazil: what is the added value of a process-based hydrological model?Characterizing the potential for drought action from combined hydrological and societal perspectivesIncorporating the logistic regression into a decision-centric assessment of climate change impacts on a complex river systemAssessment of food trade impacts on water, food, and land security in the MENA regionAssessing the effect of flood restoration on surface–subsurface interactions in Rohrschollen Island (Upper Rhine river – France) using integrated hydrological modeling and thermal infrared imagingImplications of water management representations for watershed hydrologic modeling in the Yakima River basinClimate change vs. socio-economic development: understanding the future South Asian water gapDo users benefit from additional information in support of operational drought management decisions in the Ebro basin?Global phosphorus recovery from wastewater for agricultural reuseEvaporation suppression and energy balance of water reservoirs covered with self-assembling floating elementsDeveloping a decision support tool for assessing land use change and BMPs in ungauged watersheds based on decision rules provided by SWAT simulationModeling the glacial lake outburst flood process chain in the Nepal Himalaya: reassessing Imja Tsho's hazardSeasonal streamflow forecasting in the upper Indus Basin of Pakistan: an assessment of methodsGrey water footprint reduction in irrigated crop production: effect of nitrogen application rate, nitrogen form, tillage practice and irrigation strategyFramework for developing hybrid process-driven, artificial neural network and regression models for salinity prediction in river systemsA spatially detailed blue water footprint of the United States economy
Chia-Wen Wu, Frederick N.-F. Chou, and Fong-Zuo Lee
Hydrol. Earth Syst. Sci., 25, 2063–2087,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,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,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,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,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,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.
Marc Girons Lopez, Louise Crochemore, and Ilias G. Pechlivanidis
Hydrol. Earth Syst. Sci., 25, 1189–1209,Short summary
The Swedish hydrological warning service is extending its use of seasonal forecasts, which requires an analysis of the available methods. We evaluate the simple ESP method and find out how and why forecasts vary in time and space. We find that forecasts are useful up to 3 months into the future, especially during winter and in northern Sweden. They tend to be good in slow-reacting catchments and bad in flashy and highly regulated ones. We finally link them with areas of similar behaviour.
Manon Cassagnole, Maria-Helena Ramos, Ioanna Zalachori, Guillaume Thirel, Rémy Garçon, Joël Gailhard, and Thomas Ouillon
Hydrol. Earth Syst. Sci., 25, 1033–1052,
Haiyang Shi, Geping Luo, Hongwei Zheng, Chunbo Chen, Olaf Hellwich, Jie Bai, Tie Liu, Shuang Liu, Jie Xue, Peng Cai, Huili He, Friday Uchenna Ochege, Tim Van de Voorde, and Philippe de Maeyer
Hydrol. Earth Syst. Sci., 25, 901–925,Short summary
Some river basins are considered to be very similar because they have a similar background such as a transboundary, facing threats of human activities. But we still lack understanding of differences under their general similarities. Therefore, we proposed a framework based on a Bayesian network to group watersheds based on similarity levels and compare the causal and systematic differences within the group. We applied it to the Amu and Syr Darya River basin and discussed its universality.
Michel Le Page, Younes Fakir, Lionel Jarlan, Aaron Boone, Brahim Berjamy, Saïd Khabba, and Mehrez Zribi
Hydrol. Earth Syst. Sci., 25, 637–651,Short summary
In the context of major changes, the southern Mediterranean area faces serious challenges with low and continuously decreasing water resources mainly attributed to agricultural use. A method for projecting irrigation water demand under both anthropogenic and climatic changes is proposed. Time series of satellite imagery are used to determine a set of semiempirical equations that can be easily adapted to different future scenarios.
Mohammad Taghi Sattari, Halit Apaydin, Shahab S. Band, Amir Mosavi, and Ramendra Prasad
Hydrol. Earth Syst. Sci., 25, 603–618,Short summary
The aim of study is to estimate the reference evapotranspiration (ET0) amount with artificial intelligence using minimum meteorological parameters in the Corum region, which is an agricultural center of Turkey. Kernel-based GPR and SVR and BFGS-ANN and LSTM models were used to estimate ET0 amounts in 10 different combinations. The results show that all four methods used predicted ET0 amounts at acceptable accuracy and error levels. The BFGS-ANN model showed higher success than the others.
Andres Peñuela, Christopher Hutton, and Francesca Pianosi
Hydrol. Earth Syst. Sci., 24, 6059–6073,Short summary
In this paper we evaluate the potential use of seasonal weather forecasts to improve reservoir operation in a UK water supply system. We found that the use of seasonal forecasts can improve the efficiency of reservoir operation but only if the forecast uncertainty is explicitly considered. We also found the degree of efficiency improvement is strongly affected by the decision maker priorities and the hydrological conditions.
Matteo Giuliani, Louise Crochemore, Ilias Pechlivanidis, and Andrea Castelletti
Hydrol. Earth Syst. Sci., 24, 5891–5902,Short summary
This paper aims at quantifying the value of hydroclimatic forecasts in terms of potential economic benefit to end users in the Lake Como basin (Italy), which allows the inference of a relation between gains in forecast skill and gains in end user profit. We also explore the sensitivity of this benefit to both the forecast system setup and end user behavioral factors, showing that the estimated forecast value is potentially undermined by different levels of end user risk aversion.
Michele Ferri, Uta Wehn, Linda See, Martina Monego, and Steffen Fritz
Hydrol. Earth Syst. Sci., 24, 5781–5798,Short summary
As part of the flood risk management strategy of the Brenta-Bacchiglione catchment (Italy), a citizen observatory for flood risk management is currently being implemented. A cost–benefit analysis of the citizen observatory was undertaken to demonstrate the value of this approach in monetary terms. Results show a reduction in avoided damage of 45 % compared to a scenario without implementation of the citizen observatory. The idea is to promote this methodology for future flood risk management.
Sara Suárez-Almiñana, Abel Solera, Jaime Madrigal, Joaquín Andreu, and Javier Paredes-Arquiola
Hydrol. Earth Syst. Sci., 24, 5297–5315,Short summary
This work responds to the need for an effective methodology that integrates climate change projections into water planning and management to guide complex basin decision-making. This general approach is based on a model chain for management and drought risk assessments and applied to the Júcar River basin (Spain), showing a worrying deterioration of the basin's future water resources availability and drought indicators, despite a considerable uncertainty of results from the mid-century onwards.
Shan Zuidema, Danielle Grogan, Alexander Prusevich, Richard Lammers, Sarah Gilmore, and Paula Williams
Hydrol. Earth Syst. Sci., 24, 5231–5249,Short summary
In our case study we find that increasing the efficiency of irrigation technology will have unintended consequences like reducing water available for aquifer replenishment or for other irrigators. The amount of water needed to stabilize regional aquifers exceeds the amount that could be saved by improving irrigation efficiency. Since users depend upon local groundwater storage, which is more sensitive to management decisions than river flow, comanagement of surface and groundwater is critical.
Alexander Kaune, Faysal Chowdhury, Micha Werner, and James Bennett
Hydrol. Earth Syst. Sci., 24, 3851–3870,Short summary
This paper was developed from PhD research focused on assessing the value of using hydrological datasets in water resource management. Previous studies have assessed how well data can help in predicting river flows, but there is a lack of knowledge of how well data can help in water allocation decisions. In our research, it was found that using seasonal streamflow forecasts improves the available water estimates, resulting in better water allocation decisions in a highly regulated basin.
Ghizlane Aouade, Lionel Jarlan, Jamal Ezzahar, Salah Er-Raki, Adrien Napoly, Abdelfattah Benkaddour, Said Khabba, Gilles Boulet, Sébastien Garrigues, Abdelghani Chehbouni, and Aaron Boone
Hydrol. Earth Syst. Sci., 24, 3789–3814,Short summary
Our objective is to question the representation of the energy budget in surface–vegetation–atmosphere transfer models for the prediction of the convective fluxes in crops with complex structures (row) and under transient hydric regimes due to irrigation. The main result is that a coupled multiple energy balance approach is necessary to properly predict surface exchanges for these complex crops. It also points out the need for other similar studies on various crops with different sparsity levels.
Michael Kilgour Stewart and Philippa Lauren Aitchison-Earl
Hydrol. Earth Syst. Sci., 24, 3583–3601,Short summary
This paper is important for water resource management, being concerned with irrigation return flow causing
hotspotsin nitrate concentrations in groundwater and
denitrification imprintswhere nitrate concentrations are reduced by denitrification although the dissolved oxygen concentration is not low. The work is highly significant for modelling of nitrate transport through soil–groundwater systems, for understanding denitrification processes, and for managing fertilizer application to land.
Céline Monteil, Fabrice Zaoui, Nicolas Le Moine, and Frédéric Hendrickx
Hydrol. Earth Syst. Sci., 24, 3189–3209,Short summary
Environmental modelling is complex, and models often require the calibration of several parameters that are not able to be directly evaluated from a physical quantity or a field measurement. Based on our experience in hydrological modelling, we propose combining two algorithms to obtain a fast and accurate way of calibrating complex models (many parameters and many objectives). We built an R package, caRamel, so that this multi-objective calibration algorithm can be easily implemented.
Liming Yao, Zhongwen Xu, Huijuan Wu, and Xudong Chen
Hydrol. Earth Syst. Sci., 24, 2769–2789,Short summary
Results show that coalitional strategy of blue and virtual water transfers can substantially save water and improve utilization efficiency without harming sectors' benefits and increasing ecological stresses. Under various polices, we use data-driven analysis to simulate hydrological and economic parameters, such as available water, crop import price, and water market price. Different water allocation and transfer results are obtained by adjusting hydrological and economic parameters.
Jingyuan Xue, Zailin Huo, Shuai Wang, Chaozi Wang, Ian White, Isaya Kisekka, Zhuping Sheng, Guanhua Huang, and Xu Xu
Hydrol. Earth Syst. Sci., 24, 2399–2418,Short summary
Due to increasing food demand and limited water resources, the quantification of the irrigation water productivity (IWP) is critical. Hydrological processes in irrigated areas differ in different watersheds owing to different irrigation–drainage activities, and this is more complex with shallow groundwater. Considering the complexity of the IWP, we developed a regional IWP model to simulate its spatial distribution; this informs irrigation managers on where they can improve IWP and save water.
Bouchra Ait Hssaine, Olivier Merlin, Jamal Ezzahar, Nitu Ojha, Salah Er-Raki, and Said Khabba
Hydrol. Earth Syst. Sci., 24, 1781–1803,
Matthew J. Knowling, Jeremy T. White, Catherine R. Moore, Pawel Rakowski, and Kevin Hayley
Hydrol. Earth Syst. Sci., 24, 1677–1689,Short summary
The incorporation of novel and diverse data sources into predictive models is expected to improve the reliability of model forecasts. This study critically and rigorously explores the extent to which this expectation holds given the imperfect nature of numerical models (and therefore their compromised ability to appropriately assimilate information-rich data). We show that environmental tracer observations may be of variable benefit in reducing forecast uncertainty and may induce forecast bias.
Sean W. D. Turner, Wenwei Xu, and Nathalie Voisin
Hydrol. Earth Syst. Sci., 24, 1275–1291,Short summary
To understand human vulnerability to flood and drought risk across large regions, researchers increasingly use large-scale hydrological models that convert climate to river flows. These models include the important effects of river regulation by dams but do not currently capture dam operators' use of flow forecasts to mitigate risk. This research addresses this problem by developing an approach to infer the forecast horizons contributing to the operations of a large sample of dams.
Sebastian Multsch, Maarten S. Krol, Markus Pahlow, André L. C. Assunção, Alberto G. O. P. Barretto, Quirijn de Jong van Lier, and Lutz Breuer
Hydrol. Earth Syst. Sci., 24, 307–324,Short summary
Expanding irrigation in agriculture is one of Brazil's strategies to increase production. In this study the amount of water required to grow the main crops has been calculated and compared to the water that is available in rivers at least 95 % of the time. Future decisions regarding expanding irrigated cropping areas must, while intensifying production practices, consider the likely regional effects on water scarcity levels, in order to reach sustainable agricultural production.
Guillaume Bigeard, Benoit Coudert, Jonas Chirouze, Salah Er-Raki, Gilles Boulet, Eric Ceschia, and Lionel Jarlan
Hydrol. Earth Syst. Sci., 23, 5033–5058,Short summary
The purpose of our work is to estimate landscape evapotranspiration (ET) fluxes over agricultural areas by relying on two surface modeling approaches with increasing complexity and input data needs. Both approaches, compared sequentially and over the entire crop cycle, showed quite similar performance except under developed vegetation and stressed conditions. This study helps lay the groundwork for exploring the complementarities between instantaneous and continuous ET mapping with TIR data.
Gabriela Chiquito Gesualdo, Paulo Tarso Oliveira, Dulce Buchala Bicca Rodrigues, and Hoshin Vijai Gupta
Hydrol. Earth Syst. Sci., 23, 4955–4968,Short summary
We investigate the influence of anticipated climate change on water security in the Jaguari Basin, which is the main source of freshwater for 9 million people in the São Paulo metropolitan region. Our findings indicate an expansion of the basin critical period, and identify October and November as the most vulnerable months. There is an urgent need to implement efficient mitigation and adaptation policies that recognize the annual pattern of variation between insecure and secure periods.
Raphaël Payet-Burin, Mikkel Kromann, Silvio Pereira-Cardenal, Kenneth Marc Strzepek, and Peter Bauer-Gottwein
Hydrol. Earth Syst. Sci., 23, 4129–4152,Short summary
We present an open-source tool for water infrastructure investment planning considering interrelations between the water, food, and energy systems. We apply it to the Zambezi River basin to evaluate economic impacts of hydropower and irrigation development plans. We find trade-offs between the development plans and sensitivity to uncertainties (e.g. climate change, carbon taxes, capital costs of solar technologies, environmental policies) demonstrating the necessity for an integrated approach.
Fuad Yassin, Saman Razavi, Mohamed Elshamy, Bruce Davison, Gonzalo Sapriza-Azuri, and Howard Wheater
Hydrol. Earth Syst. Sci., 23, 3735–3764,
Eric Sauquet, Bastien Richard, Alexandre Devers, and Christel Prudhomme
Hydrol. Earth Syst. Sci., 23, 3683–3710,Short summary
This study aims to identify catchments and the associated water uses vulnerable to climate change. Vulnerability is considered here to be the likelihood of water restrictions which are unacceptable for agricultural uses. This study provides the first regional analysis of the stated water restrictions, highlighting heterogeneous decision-making processes; data from a national system of compensation to farmers for uninsurable damages were used to characterize past failure events.
Jessica R. Dzara, Bethany T. Neilson, and Sarah E. Null
Hydrol. Earth Syst. Sci., 23, 2965–2982,Short summary
In Nevada's Walker River, stream temperatures nearly always exceed optimal temperature thresholds for adult trout. We used high-resolution measured data to verify simulated stream temperatures and estimate the spatial distribution of cold-water pockets for fish. Irrigation return canals, beaver dams, and groundwater seeps were river features with cold-water, and the average distance between pockets of cold-water in this river was 2.8 km.
Xinyao Zhou, Yonghui Yang, Zhuping Sheng, and Yongqiang Zhang
Hydrol. Earth Syst. Sci., 23, 2491–2505,Short summary
Quantifying the impact of upstream water use on downstream water scarcity is critical for water management. Comparing natural and observed runoff in China's 12 basins, this study found surface water use increased 1.6 times for the 1970s-2000s, driving most arid and semi-arid (ASA) basins into water scarcity status. The water stress decreased downstream in ASA basins due to reduced upstream inflow since the 2000s. Upstream water use caused over a 30 % increase in water scarcity in ASA basins.
Alexander Kaune, Micha Werner, Patricia López López, Erasmo Rodríguez, Poolad Karimi, and Charlotte de Fraiture
Hydrol. Earth Syst. Sci., 23, 2351–2368,Short summary
The value of using longer periods of record of river discharge information from global precipitation datasets is assessed for irrigation area planning. Results show that for all river discharge simulations the benefit of choosing the irrigated area based on the 30 years of simulated data is higher compared to using only 5 years of observed discharge data. Hence, irrigated areas can be better planned using 30 years of river discharge information from global precipitation datasets.
Tobias Pilz, José Miguel Delgado, Sebastian Voss, Klaus Vormoor, Till Francke, Alexandre Cunha Costa, Eduardo Martins, and Axel Bronstert
Hydrol. Earth Syst. Sci., 23, 1951–1971,Short summary
This work investigates different model types for drought prediction in a dryland region. Consequently, the performances of seasonal reservoir volume forecasts derived by a process-based and a statistical hydrological model were evaluated. The process-based approach obtained lower accuracy while resolution and reliability of drought prediction were comparable. Initialisation of the process-based model is worthwhile for more in-depth analyses, provided adequate rainfall forecasts are available.
Erin Towler, Heather Lazrus, and Debasish PaiMazumder
Hydrol. Earth Syst. Sci., 23, 1469–1482,Short summary
Drought is a function of both natural and human influences, but fully characterizing the interactions between human and natural influences on drought remains challenging. To better characterize the drought feedback loop, this study combines hydrological and societal perspectives to characterize the potential for drought action. We discuss how the results can be used to reduce potential disagreement among stakeholders and promote sustainable water management.
Daeha Kim, Jong Ahn Chun, and Si Jung Choi
Hydrol. Earth Syst. Sci., 23, 1145–1162,Short summary
In this study, we proposed an approach for gauging the risks of non-successful water supply and environmental reliabilities varying across a large river basin. The proposed method enables the measurement of system robustness to climate change with consideration of conflicting stakeholder interests. We simply converted the expected system performance under climate stresses into binary outcomes and applied them to the logistic regressions. A case study for a South Korean river basin is provided.
Sang-Hyun Lee, Rabi H. Mohtar, and Seung-Hwan Yoo
Hydrol. Earth Syst. Sci., 23, 557–572,Short summary
In this study, we quantified the holistic impacts of food trade on food security and water–land savings and revealed that the MENA region saved significant amounts of national water and land based on the import of barley, maize, rice, and wheat within the period from 2000 to 2012. In addition, the MENA region focused more on increasing the volume of virtual water imported during the period 2006–2012, yet little attention was paid to the expansion of connections with country exporters.
Benjamin Jeannot, Sylvain Weill, David Eschbach, Laurent Schmitt, and Frederick Delay
Hydrol. Earth Syst. Sci., 23, 239–254,Short summary
A hydrological model is used in combination with thermal measurements to investigate the effect of restoration actions in an artificial island of the Upper Rhine river. The injection of water in a newly built channel is efficient as it enhances overall hydrologic dynamics of the system with possible benefits for water quality and biodiversity. The combined use of the model and thermal measurements is also proven to be a relevant tool to study the effect of restoration on hydrological systems.
Jiali Qiu, Qichun Yang, Xuesong Zhang, Maoyi Huang, Jennifer C. Adam, and Keyvan Malek
Hydrol. Earth Syst. Sci., 23, 35–49,Short summary
Complex water management activities challenge hydrologic modeling. We evaluated how different representations of reservoir operation and agricultural irrigation affect streamflow simulations in the Yakima River basin. Results highlight the importance of the inclusion of reliable reservoir and irrigation information in watershed models for improving watershed hydrology modeling. Models used here are public and hold the promise to benefit water assessment and management in other basins.
René Reijer Wijngaard, Hester Biemans, Arthur Friedrich Lutz, Arun Bhakta Shrestha, Philippus Wester, and Walter Willem Immerzeel
Hydrol. Earth Syst. Sci., 22, 6297–6321,Short summary
This study assesses the combined impacts of climate change and socio-economic developments on the future water gap for the Indus, Ganges, and Brahmaputra river basins until the end of the 21st century. The results show that despite projected increases in surface water availability, the strong socio-economic development and associated increase in water demand will likely lead to an increase in the water gap, indicating that socio-economic changes will be the key driver in the evolving water gap.
Clara Linés, Ana Iglesias, Luis Garrote, Vicente Sotés, and Micha Werner
Hydrol. Earth Syst. Sci., 22, 5901–5917,Short summary
In this paper we follow a user-based approach to examine operational drought management decisions and how the role of information on them can be assessed. The approach combines a stakeholder consultation and a decision model representing the interrelated decisions of the irrigation association and farmers. The decision model was extended to include information on snow cover from satellite. This contributed to better decisions in the simulation and ultimately higher benefits for the farmers.
Dirk-Jan D. Kok, Saket Pande, Jules B. van Lier, Angela R. C. Ortigara, Hubert Savenije, and Stefan Uhlenbrook
Hydrol. Earth Syst. Sci., 22, 5781–5799,Short summary
Phosphorus (P) is important to global food security. Thus it is concerning that natural P reserves are predicted to deplete within the century. Here we explore the potential of P recovery from wastewater (WW) at global scale. We identify high production and demand sites to determine optimal market prices and trade flows. We show that 20 % of the agricultural demand can be met, yet only 4 % can be met economically. Nonetheless, this recovery stimulates circular economic development in WW treatment.
Milad Aminzadeh, Peter Lehmann, and Dani Or
Hydrol. Earth Syst. Sci., 22, 4015–4032,Short summary
Significant evaporative losses from local water reservoirs in arid regions exacerbate water shortages during dry spells. We propose a systematic approach for modeling energy balance and fluxes from covered water bodies using self-assembling floating elements, considering cover properties and local conditions. The study will provide a scientific and generalized basis for designing and implementing this important water conservation strategy to assist with its adaptation in various arid regions.
Junyu Qi, Sheng Li, Charles P.-A. Bourque, Zisheng Xing, and Fan-Rui Meng
Hydrol. Earth Syst. Sci., 22, 3789–3806,Short summary
The paper proposed an approach to develop a decision support tool to evaluate impacts of land use change and best management practices (BMPs) on water quantity and quality for large ungauged watersheds. It was developed based on statistical equations derived from Soil and Water Assessment Tool (SWAT) simulations in a small experimental watershed. The decision support tool reproduced annual stream discharge and sediment and nutrient loadings for another watershed fairly well.
Jonathan M. Lala, David R. Rounce, and Daene C. McKinney
Hydrol. Earth Syst. Sci., 22, 3721–3737,Short summary
Many glacial lakes in the Himalayas are held in place by natural sediment dams, which are prone to collapse, causing a glacial lake outburst flood (GLOF). This study models a GLOF as a process chain, in which an avalanche enters the lake, creates a large wave that erodes the sediment dam, and produces a flood downstream. Results indicate that Imja Tsho presents little hazard for the next 30 years, but the model is replicable and should be used at other lakes that may present greater hazard.
Stephen P. Charles, Quan J. Wang, Mobin-ud-Din Ahmad, Danial Hashmi, Andrew Schepen, Geoff Podger, and David E. Robertson
Hydrol. Earth Syst. Sci., 22, 3533–3549,Short summary
Predictions of irrigation-season water availability are important for water-limited Pakistan. We assess a Bayesian joint probability approach, using flow and climate indices as predictors, to produce streamflow forecasts for inflow to Pakistan's two largest dams. The approach produces skilful and reliable forecasts. As it is simple and quick to apply, it can be used to provide probabilistic seasonal streamflow forecasts that can inform Pakistan's water management.
Abebe D. Chukalla, Maarten S. Krol, and Arjen Y. Hoekstra
Hydrol. Earth Syst. Sci., 22, 3245–3259,Short summary
This paper provides the first detailed and comprehensive study regarding the potential for reducing the grey WF of crop production by changing management practice such as the nitrogen application rate, nitrogen form (inorganic N or manure N), tillage practice and irrigation strategy. The paper shows that although water pollution (grey WF) can be reduced dramatically, this comes together with a great yield reduction.
Jason M. Hunter, Holger R. Maier, Matthew S. Gibbs, Eloise R. Foale, Naomi A. Grosvenor, Nathan P. Harders, and Tahali C. Kikuchi-Miller
Hydrol. Earth Syst. Sci., 22, 2987–3006,Short summary
This research proposes a generalised hybrid model development framework and applies it to a case study of salinity prediction in a reach of the Murray River. The hybrid model combines five sub-models which describe one process of salt entry each and are developed based on the amount of system knowledge and data that are available to support each individual process. The model demonstrates increased performance over two benchmark models and has implications for future model development processes.
Richard R. Rushforth and Benjamin L. Ruddell
Hydrol. Earth Syst. Sci., 22, 3007–3032,Short summary
The National Water Economy Database is a new data resource to better understand the human economy's water use impact on the hydrosphere. NWED quantifies and maps a spatially detailed and economically complete blue water footprint for the United States, utilizing several datasets: US Geological Survey, the US Department of Agriculture, the US Energy Information Administration, the US Department of Transportation, the US Department of Energy, and the US Bureau of Labor Statistics.
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.
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...