ion, afforestation, urbanisation (Grootjans et al. 1998; Martinez et al., 2004; Provoost 106 et al., 2011), nitrogen deposition (Jones et al., 2004; Plassmann et al., 2008; Sival and 107 Strijkstra-Kalk, 1999) and from grass and scrub encroachment or exotic species invasion 108 (Martinez et al., 2004). In addition, changes in evapotranspiration due to vegetation change or 109 management will af...

In many semi-arid basins during extended periods when surface snowmelt or storm runoff is absent, groundwater constitutes the primary water source for human habitation, agriculture and riparian ecosystems. Utilizing regional groundwater models in the management of these water resources requires accurate estimates of basin boundary conditions. A critical groundwater boundary condition that is cl...

Riparian forests can remove large amounts of nitrate from the groundwater discharges of adjacent uphill croplands. We review the mechanisms that could account for NO3 removal. Denitrification is hypothesized to be important, but measurement problems limit the relevant field data. We used large chambers (1-20 mZ) and tunable-diode laser infrared spectrophotometry to measure nitrous oxide (NzO) e...

Multi-objective optimization was used to calibrate a regional surface water-groundwater model of the Yaqui Valley, a 6800 km2 irrigated agricultural region located along the Sea of Cortez in Sonora, Mexico. The model simulates three-dimensional groundwater flow coupled to onedimensional surface water flow in the irrigation canals. It accounts for the spatial distribution of annual recharge from...

Groundwater resources are increasingly being relied on in rural areas for income generation and food security. However, there is currently a lack of simple, yet accessible hydrogeological tools to monitor critical groundwater resources, both for quantity and quality. This is particularly true in developing countries underlain by fractured hard rock aquifers, with low productivities. Electrical ...

Th e aims of the study were to apply, test and to present the ability of the deterministic simulation models SIMWASER and CERES-Wheat computing soil-water balance components, percolation losses, ground water recharge and capillary rise. Two case studies for the assessment of percolation losses from irrigated carrots to deep groundwater at Obersiebenbrunn in the Marchfeld (Austria) and ground wa...

This study tests the representativeness of groundwater recharge estimates through the chloride mass balance (CMB) method in a tropical environment. The representativeness of recharge estimates using this methodology is tested using evaporation estimates from isotope data, the general spatial distribution of the potential field, and the topographical variations in the area. This study suggests t...

Sustainable groundwater production from karst aquifers is primarily dictated by its recharge rate. Therefore, it is essential to accurately quantify annual groundwater recharge in order to limit overexploitation and to evaluate artificial methods for groundwater enrichment. Infiltration during erratic flood events in karst basins may substantially contribute to aquifer recharge. However, the co...

High levels of naturally occurring and carcinogenic radium isotopes have been measured in low-saline and oxic groundwater from the Rum Group of the Disi sandstone aquifer in Jordan. The combined 228Ra and 226Ra activities are up to 2000% higher than international drinking water standards. Analyses of the host sandstone aquifer rocks show 228Ra and 226Ra activities and ratios that are consistent...

This study evaluates the piezometric weighing lysimeter method of van der Kamp and Schmidt, based on two annual cycles of measurements in a mature boreal aspen forest in western Canada. The method is used to infer components of the moisture balance on a scale of hectares. The method is based on accurate measurement of groundwater pore pressure in thick clay formations, and depends on the princi...