Water tables are dropping by approximately one meter annually throughout the North China Plain mainly due to water withdrawals for irrigating winter wheat year after year. In order to examine whether the drawdown can be reduced we calculate the net water use for an 11 year field experiment from 2003 to 2013 where six irrigated crops (winter wheat, summer maize, cotton, peanuts, sweet potato, ry...

this paper gives an account of the implementation of geomorphological, hydrogeological, hydrochemical and isotopic techniques to understand groundwater-surface water interactions in a multiple use area, los padres-la brava corridor (se of buenos aires province, argentina). the isophreatic map reveals a regional flow from the sw to ne sector, and allowed us to define the effluent-influent behav...

Dairy farms comprise a complex landscape of groundwater pollution sources. The objective of our work is to develop a method to quantify nitrate leaching to shallow groundwater from different management units at dairy farms. Total nitrate loads are determined by the sequential calibration of a sub-regional scale and a farm-scale three-dimensional groundwater flow and transport model using observ...

A simple rainfall-runoff model (Vardavas, I.M., 1988. A simple water balance daily rainfall-runoff model with application to the tropical Magela Creek catchment. Ecol. Model 42, 245–264) developed and applied to the tropical wet–dry Magela catchment in the Northern Territory of Australia has been modified and applied to the Mediterranean wet–dry Messara Valley catchment of Crete. The Messara Va...

Geochemical evaluation of the sources and movement of saline groundwater in coastal aquifers can aid in the initial mapping of the subsurface when geological information is unavailable. Chloride concentrations of groundwater in a coastal aquifer near San Diego, California, range from about 57 to 39,400 mg/L. On the basis of relative proportions of major-ions, the chemical composition is classif...

The unmanaged groundwater extraction and inadequate aquifer recharge is the major cause of groundwater depletion in different parts of the world. In this study, the groundwater flow system of Mahvelat-Feizabad aquifer (NE of Iran) has been numerically simulated using MODFLOW code in the GMS interface. The model, primarily, calibrated for steady state condition for the mean hydraulic values of o...

Groundwater from remote parts of the Middle Rio Grande Basin in north-central New Mexico has perchlorate (ClO4-) concentrations of 0.12-1.8 micro/L. Because the water samples are mostly preanthropogenic in age (0-28000 years) and there are no industrial sources in the study area, a natural source of the ClO4- is likely. Most of the samples have Br-, Cl-, and SO4(2-) concentrations that are simi...