for better understanding of tehran ground water, samples were taken randomly from 340 out of 655 deep & semi deep wells in 1993, which dug by tehran water supply and sewage engineering company. 260 water specimens were examined chemically and physically and compared with the 1993 world health organization (who) and food and agriculture organization (fao) criteria and analyzed statistically. log...

background: nitrate and nitrite compounds are considered as groundwater’s contamination factors, which in recent years, their densities have been growing in these resources. this study was conducted aiming to measure nitrate and nitrite density in drinking water wells in villages around the industrial estate, city of orumieh, and to compare them to the approved standards. methods: this was a de...

satellite data have been used for temperature modeling both in urban areas and water. this paperstudies viability of aster satellite images that provide high spatial and spectral resolution to model watersurface temperature, as a fundamental water quality parameter. this study is focused on dez dam reservoirresiding in khuzestan province, south west of iran. after the image corrections required...

Modeling landscape with high-resolution digital elevation data (DEM) in a geographic information system can provide essential morphological and structural information for modeling surface processes such as geomorphologic process and water systems. This paper introduces several DEM-based spatial analysis processes applied to characterize spatial distribution and interactions of ground and surfac...

Water Howellia (Howellia aquatilis) is a rare and endangered wetland plant listed as a threatened species under the Federal Endangered Species Act. 70% of the world population is found in the 1:7 £ 10 ha Swan Valley, Montana, USA in wetlands of usually less than 1-ha. Survival of this aquatic species requires emergence during mid-summer, the drying out of occupied portions of the wetlands, a sl...

Main perennial rivers of Gujarat, Tapi, Narmada, Mahi and Sabarmatiare meeting Arabian Sea in Gulf of Khambhat. The out flow of Mahi River intothe sea is decreased due to construction of dams like Bajaj Sagar, Kadana, Panamand Wanakbori weir. So, Tidal effect of sea and sea water intrusion is beingincreased on landward side. Moreover, due to erratic nature of rainfall andimproper management of ...

GSFLOW is a new U.S. Geological Survey model for simulating ground-water/surface-water interactions. GSFLOW couples PRMS (the Precipitation Runoff Modeling System) to MODFLOW (the Modular Ground-Water Model) with modules for simulating flow and storage in unsaturated-zones, lakes, and streams. GSFLOW simulates infiltration, runoff generation, and lateral flow in temporarily saturated material (...

Numerical models that account for the effects of fluid density on ground water flow are being used more frequently to address scientific, engineering, and water resource management problems (Voss and Wood 1993; Voss 1999; Voss and Andersson 1993; Simmons et al. 1999; Simmons et al. 2002; Shoemaker and Edwards 2003; Langevin 2001). Also being used more frequently are inverse modeling routines ba...

Uncertainty of hydrogeologic conditions makes it important to consider alternative plausible models in an effort to evaluate the character of a ground water system, maintain parsimony, and make predictions with reasonable definition of their uncertainty. When multiple models are considered, data collection and analysis focus on evaluation of which model(s) is(are) most supported by the data. Ge...

Global sensitivity analysis techniques are better suited for analyzing input-output relationships over the full range of parameter variations and model outcomes, as opposed to local sensitivity analysis carried out around a reference point. This article describes three such techniques: (1) stepwise rank regression analysis for building input-output models to identify key contributors to output ...