BACKGROUND The nontherapeutic use of antibiotics in swine feed can select for antibiotic resistance in swine enteric bacteria. Leaking swine waste storage pits and the land-application of swine manure can result in the dispersion of resistant bacteria to water sources. However, there are few data comparing levels of resistant bacteria in swine manure-impacted water sources versus unaffected sou...

Karst regions, occupy approximately 25% of the land surface of the earth. Karst aquifers are often major sources of water supply in these areas. However, karst aquifers are generally considered to be particularly vulnerable to pollution and anthropogenic impacts. Large withdrawals of water in karst areas for municipal, agricultural, and industrial use may competitively affect water supply in su...

The nuclear weapons testing programme of the USA has released radionuclides to the subsurface at the Nevada Test Site. One of these tests has been used to study the hydrological transport of radionuclides for over 25 years in groundwater and the deep unsaturated zone. Ten years after the weapon's test, a 16 year groundwater pumping experiment was initiated to study the mobility of radionuclides...

Whole-watershed accounting assesses all surface and groundwater flows and storage over a large area. The idea is to account for all the major sources of water at once, rather than focusing on only a portion of them, such as what’s stored in surface water reservoirs. This work can reveal how joint management of surface and groundwater flows and storage could increase the overall amount of water ...

[1] Fluvial erosion on early Mars was dominated by valley networks created through a combination of groundwater processes and surface runoff. A reduced greenhouse effect due to CO2 loss, together with a declining geothermal heat flux, promoted the growth of a cryosphere and a Hesperian hydrologic regime dominated by outflow channel formation. We test the hypothesis that the transition from vall...

The changes in human population often correspond with change in land use, including expansion of urban areas, agriculture and increasing industrialization, which necessitate increasing the available amount of drinking water. As the surface water sources are under the pressure of pollution, it has become necessary to use groundwater at an increasing rate. Groundwater recharge can be abundant in ...

excessive withdrawal of groundwater and reduced rainfall in recent years have caused the drawdown of groundwater table. therefore, it is necessary to manage it for preventing its damage. the present study was carried out to investigate the effect of increasing the irrigation efficiency on groundwater fluctuation on ajab-shir plain aquifer. the aquifer was simulated by using visual modflow 3.1 s...

for more than half a century isotopes have been employed as a powerful tool in studying various aspects of water resources in a largenumber of countries. however, in developing countries like iran the application of such techniques is in its infancy. the first research iniran was carried out in 1975 to identify the source of saline groundwaters in south iran, and the first national conference o...