We combine radon and stable isotopes in water to determine total submarine groundwater discharge (SGD) in the Ria Formosa and discriminate its component modes. We show that tidal action filters the entire water volume in the lagoon through local beaches 3.5 times a year, driving an estimated 350Ton nitrogen/year into the system. Conversely, fresh groundwater is discharged into the lagoon only occasionally, adding ~ 61 Ton nitrogen/year, but is capable of driving new production in the system.

Efficient groundwater protection from pollution originating in agriculture requires effective monitoring means capable of tacking pollution processes in the vadose zone, long before groundwater pollution turns into an unavoidable fact. In this study, a vadose zone monitoring system that was installed under a crop field fertilized by dairy slurry enabled real-time tracking of nitrate plum migration down the vadose zone from the land surface to the water table at 18m depth.

Forecasts are produced as probabilities of occurrence of specific events, which is both an added value and a challenge for users. This paper presents a game on flood protection, "How much are you prepared to pay for a forecast?", which investigated how users perceive the value of forecasts and are willing to pay for them when making decisions. It shows that users are mainly influenced by the perceived quality of the forecasts, their need for the information and their degree of risk tolerance.

We assess the sustainability of planned water uses in complex mesoscale river basins by modeling water demand and availability under climatic and anthropogenic changes. We present an analysis through indicators that relate to water management goals. The impacts of climate projections on both water availability and demand question the water allocations and environmental constraints currently planned for the coming decades. This work brings an essential long-term perspective to water sharing plans.

The anticipation of sea-level rise has led to an innovative project called the Sand Engine, where a large volume of sand was placed on the Dutch coast. The intention is that the sand is redistributed by wind, current and tide, reinforcing coastal defence structures. Model simulations show that this large sand replenishment can result in a substantial growth of fresh groundwater resources. Thus, sand replenishments could combine coastal protection with an increase of fresh groundwater resources.

The Tibetan Plateau plays a major role in regional and global climate. The knowledge of latent heat flux can help to better describe the complex interactions between land and atmosphere. The purpose of this paper is to provide a detailed cross-comparison of existing latent heat flux products over the TP. The results highlight the recently developed latent heat product – High Resolution Land Surface Parameters from Space (HOLAPS).

Bivariate wavelet coherence has been used to explore scale- and location-specific relationships between two variables. In reality, a process occurring on land surface is usually affected by more than two factors. Therefore, this manuscript is to develop a multiple wavelet coherence method. Results showed that new method outperforms other multivariate methods. Matlab codes for a new method are provided. This method can be widely applied in geosciences where a variable is controlled by many factors.

We study detectability of changes in water surface areas on orthophotomaps. We use unmanned aerial vehicles to acquire visible light photographs. We offer a new method for detecting changes in water surface areas and river stages. The approach is based on the application of the Student's t test, in asymptotic and bootstrapped versions. We test our approach on aerial photos taken during 3-year observational campaign. We detect transitions between all characteristic river stages using drone data.

Geomorphometry, the science of quantitative terrain characterization, has traditionally focused on the investigation of terrestrial landscapes. More recently, a suite of geomorphometric techniques have been applied to characterize the seafloor. The dynamic, four-dimensional nature of the marine environment and differences in data collection methods cause issues for geomorphometry that are specific to marine applications. This article offers the first review of marine geomorphometry to date.

Projecting water deficit depends on how researchers combine possible future climate scenarios such as general circulation models (GCMs), evapotranspiration estimation method (ET), and greenhouse gas emission scenarios. Using global sensitivity analysis, we found the relative contribution of each of these factors to projecting future water deficit and the choice of ET estimation method are as important as the choice of GCM, and greenhouse gas emission scenario is less influential than the others.

We test the cloud tolerance of two technologies to estimate land surface temperature (LST) from space: microwave (MW) and thermal infrared (TIR). Although TIR has slightly lower errors than MW with ground data under clear-sky conditions, it suffers increasing negative bias as cloud cover increases. In contrast, we find no direct impact of clouds on the accuracy and bias of MW-LST. MW-LST can therefore be used to improve TIR cloud screening and increase sampling in clouded regions.

Oceanic–atmospheric climate modes, such as El Niño–Southern Oscillation (ENSO), are known to affect the streamflow regime in many rivers around the world. A new method is presented for ENSO conditioning of the ensemble streamflow prediction (ESP) method, which is often used for seasonal streamflow forecasting. The method was tested on three tributaries of the Columbia River, OR. Results show an improvement in forecast skill compared to the standard ESP.

We derive a new dual ensemble Kalman filter (EnKF) for state-parameter estimation. The derivation is based on the one-step-ahead smoothing formulation, and unlike the standard dual EnKF, it is consistent with the Bayesian formulation of the state-parameter estimation problem and uses the observations in both state smoothing and forecast. This is shown to enhance the performance and robustness of the dual EnKF in experiments conducted with a two-dimensional synthetic groundwater aquifer model.

In this study, we focused on analyzing the variation and factors influencing deep soil moisture content based on a soil moisture survey of the Ansai watershed. Our results revealed the variation characteristics of deep soil moisture and its controlling mechanism at a moderate scale. The results of this study are of practical significance for vegetation restoration strategies and the sustainability of restored ecosystems.

Current water quality problems due to intensification of corn in agricultural watersheds is expected to be exacerbated by the projected change in climate further in the 21st century. Therefore, there is an urgent need to develop alternative biofuel cropping systems and/or implement effective management practices to counteract future water quality problems that could develop from relying on extensive production of row crops in Corn Belt region watersheds.

Impacts of climate change on hydropower potential of China are investigated using projections from multiple general circulation models and global hydrological models. Results show that the projected total hydropower potential of China generally increases (e.g., in southwest China) while the maximum production of current hydropower stations may decrease (e.g., in Sichuan and Hubei provinces) in the future. This study prompts the consideration of climate change in hydropower planning in China.

We demonstrated that the readily available NDII remote sensing product is a very useful proxy for moisture storage in the root zone of vegetation. We compared the temporal variation of the NDII with the root zone storage in a hydrological model of eight catchments in the Upper Ping River in Thailand, yielding very good results. Having a reliable NDII product that can help us to estimate the actual moisture storage in catchments is a major contribution to prediction in ungauged basins.

Application of digital terrain analysis (DTA), which is typically a modeling process involving workflow building, relies heavily on DTA domain knowledge. However, the DTA knowledge has not been formalized well to be available for inference in automatic tools. We propose a case-based methodology to solve this problem. This methodology can also be applied to other domains of geographical modeling with a similar situation.

In this work we analyse the recent evolution and meteorological drivers of the atmospheric evaporative demand in the Canary Islands. We found that the reference evapotranspiration increased by 18.2 mm decade⁻¹ – on average – between 1961 and 2013, with the highest increase recorded during summer. This increase was mainly driven by changes in the aerodynamic component, caused by a statistically significant reduction of the relative humidity.

We developed an analytical method to estimate thermal attributes (seasonal and diel periodicities as well as irregularities) in stream temperature at data-poor sites. We extrapolated the thermal attributes of a glacier-fed stream in the Swiss Alps using 2 years of hourly recorded temperature to the data-poor sites. The R scripts used in this study are available in the Supplement.

The goal of this study was to compare how differences in urban stream restoration and sanitary infrastructure affect sources and fluxes of water and nutrients. Stream restoration reduced peak discharge and lowered nutrient export compared to unrestored streams, but was similar to a stream with upland stormwater management. The primary source of nitrate at all sites was leaky sanitary sewers, suggesting that combining stream restoration with sanitary pipe repairs may help reduce nutrient loads.

This theoretical paper describes the energy fluxes and dissipation along the flow paths involved in root water uptake, an approach that is rarely taken. We show that this provides useful additional insights for understanding the biotic and abiotic impediments to root water uptake. This approach shall be applied to explore efficient water uptake strategies and help locate the limiting processes in the complex soil–plant–atmosphere system.