Stream Water Quality Modeling in Ankara Metropolitan Area
At the time this study was undertaken, untreated wastewaters from Ankara metropolitan area (capital of Turkish Republic) were being discharged directly into Ankara Creek and its tributaries....

Underground Water Conservation Districts: A Case Study in Water Resources Management
Ground water supplies approximately half of the annual water use in the state of Texas. The water law system in the state is extremely complex and non-integrated, making the management...

Effects of Uranium Mining, Puerco River, New Mexico
Effluent from uranium-mine dewatering and acidic water released by a tailings-pond dike failure increased radionuclide activities in streamflow in the Puerco River in New Mexico and Arizona....

Use of Stable Isotopes, Tritium, Soluble Salts, and Redox-Sensitive Elements to Distinguish Ground Water from Irrigation Water in the Salton Sea Basin
Evaporative concentration of irrigation water diverted from the Colorado River to the Salton Sea basin for several decades has produced an overlying system (that includes drainwater and...

Uncertainty in Pesticide Leaching Potential
Uncertainty in the pesticide leaching index AF is examined for the pesticides Atrazine and Diuron with attention to the contribution of temporal variability and estimation error in recharge....

Economic Evaluation of Farning Systems to Protect Surface and Ground Water Quality
Two approaches are discussed for evaluating the economic and environmental effects of farming systems designed to protect water quality. The scenario approach evaluates specific farming...

Ground Water Impacts from Irrigated Ridge-Tillage
The Northern Cornbelt Sand Plain Project is a cooperative research effort between the State Agricultural Experiment Stations, USDA/Agricultural Research Service and U.S. Geological Survey...

Impact of Nitrogen and Water Management on Ground Water Quality
Nitrate-nitrogen (NO3-N) concentrations in shallow ground water of the Platte River Valley in Central Nebraska have been increasing since the 1950s...

Impact of Farming Systems on Water Quality in Iowa
Increased detection of nitrate and pesticides in surface and ground water has prompted concern about the impact of farming systems on water quality. A number of studies have been incorporated...

Long-Term Effects of Tillage and Crop Rotation on the Leaching of Nitrate and Pesticides to Shallow Groundwater
Contamination of groundwater by nitrate-nitrogen (NO3-N) and pesticides is a serious problem and concern in Iowa. The extent of contamination can...

Modeling Nitrogen Movement Through Loess Soils
This study evaluates the ability of the Root Zone Water Quality Model (RZWQM) to track the movement and fate of nitrate (NO3--N)...

Irrigation Management to Control Sediment Pollution
Unchecked serious irrigation erosion occurs on 20% or 10+ million irrigated acres in the U.S. It may cause water use impairment from sediment pollution. Serious erosion in many areas can...

The National Water-Quality Assessment (NAWQA) Program?A Basis for Water-Resource Policy Development
The concepts that are the basis for the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) program began forming in the early 1980's. By 1986,...

Overview of the Ohio Management Systems Evaluation Area
The Ohio Buried Valley Aquifer Management System Evaluation Area (Ohio MSEA) project is part of a regional study developed to investigate the effects of farming systems on productivity,...

Nutrient Loads to Delaware's Inland Bays Estuary
A management plan has been developed for the Inland Bays which is a major coastal estuary. Agriculture is the largest contributor of nitrogen and phosphorus to the Inland Bays. Best management...

Phosphorus Transport from Delaware's Rural Watershed
Phosphorus loads were estimated for 62 watersheds. Major land uses in the watersheds were cropland and forestland. Annual phosphorus loads varied from 0.42 to 1.19 kg/ha. Watersheds with...

Tributary Pollutant Effects in the Urban Stream Network
With considering unsteady flow and backwater effects, a linear water quality model is developed based on the finite difference approximation. The model is composed to two components which...

Effects of Drainage on Water, Sediment and Biota
The U.S. Department of the Interior started a program in 1985 to identify effects of irrigation-induced trace constituents in water, bottom sediment and biota. The program was developed...

Effects of Wastewater Irrigation on Aqueous Geochemistry
A comprehensive assessment of the environmental impact of a full-scale, operating overland flow (OLF) land treatment system was made of the Campbell Soup, Inc. OLF system in Paris, Texas....

Common Mistakes in Model Applications
To apply models to groundwater problems, the hydrologist generally uses the following three-phased approach: (1) system conceptualization, (2) history matching (or model calibration),...

 

 

 

 

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