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...

Thermal Regimes at Tailwaters of Hydroelectric Dam
Continuous temperature data were collected in the field for periods of approximately two weeks in Center Hill Tailwater. These data were analyzed to determine the warming rates and travel...

Two-Dimensional Analysis of Furrow Infiltration
A general applicable two-dimensional unsaturated-saturated model for transient soil-water flow conditions in heteogeneous soils was developed. The water flow model was applied to simulate...

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,...

Heavy Metal Transport in the Columbia River, British Columbia
Data on the total forms of selected metals were used to assess their concentrations at two sampling sites on the Canadian Columbia River from 1984 to 1989. Cadmium, the response variable...

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...

Discharge Forecast of Underground Tunnel System
An underground tunnel system can be discribed with linear system theory and its mathematical model can be made up according to its recharge and discharge conditions. But, because of so...

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...

History of Irrigation Water Development in Hawaii
Hawaii has a rich heritage of irrigated agriculture from the time of the first Polynesian settlers to the present. Following the ancient stream diversions by Hawaiians, sugar planters...

Imperial Irrigation District Water Conservation
Imperial Irrigation District (IID) and Metropolitan Water District (MWD) have entered into a Water Conservation Agreement to conserve 106, 110 acre-feet (1.31 ? 108...

Flexible Supply Schedule Missing Link for Effective Surface Irrigation and Automation
Surface irrigation methods - furrow and border-strip are generally thought of as being inefficient and labor intensive. Careful evaluations have shown that as methods they can be very...

Plugging Evaluation in the Re-Use of Sewage Effluent by Drip Irrigation
Primary and secondary effluent can be reused for irrigation by a drip system. When a proper lateral line with an emitter size of 0.75 mm is selected, the plugging can be maintained at...

Forecasting Irrigation Water Supply Using a Computer Model and Remotely Sensed Snow Cover
Improved streamflow forecasting in the Sevier River Basin is one objective of the Sevier River Water Management Study. Short-term forecasts are needed for optimum operations of irrigation...

Enhanced Multi-Dimensional Modelling of Marshes and Wetlands
This paper summarizes the verification and application of a two-dimensional finite element model capable of simulating the complex circulation characteristics in marshes and wetlands for...

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...

 

 

 

 

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