Nonpoint Source Pollution Model for Agricultural and Rural Watersheds
A dynamic hydrologic and nonpoint source pollution simulation model for agricultural and rural watersheds; capable of simulating rainfall-runoff, soil erosion, sediment transport, mixing...

Numerical Estimation of Macrodispersivities in Heterogeneous Self-similar Aquifers
Numerical simulations of contaminant transport in a stratified aquifer characterized by a self-similar distribution of hydraulic conductivity were performed. Macrodispersivities were calculated...

Simulation of the Propagation of Conserevative Contamination
The hydrodynamic model of the pollutant transport in water bodies was developed and adopted for Volga water supply system of Moscow, which includes five reservoirs and a channel. The model...

A Two-Dimensional Flow and Hydrogeochemical Transport Model
A two-dimensional flow and hydrogeochemical transport model is designed for estimating the movement and attenuation of chemicals after they are released into subsurface systems. This model...

Investigation of Chloroform Plumes in a Porous Media
A sand box model was used in the laboratory to study the development and stability of the contaminant plume with respect to space and time. Steady, uniform flow velocities were established...

Flow and Transport of Nonaqueous Phase Liquids in Groundwater Systems
Nonaqueous phase liquids (NAPLs) are present at numerous hazardous waste sites and are suspected to exist at many more. Due to the numerous variables influencing NAPL transport and fate...

Runoff Prediction by Recession Curves
Based on the characteristics of the discharge hydrograph such as the rising limb and the recession curve, a simple water tank model is constructed. This water tank has cross-sectional...

Verification Tests for Transport Modeling in Coastal Aquifers
The U.S. Geological Survey three dimensional Heat and Solute Transport (HST3D) model is used to simulate fate and transport of dissolved contaminant in coastal aquifers. The model originally...

Polyacrylamide Decreases Furrow Erosion
Erosion from furrow irrigated land is a serious problem in southern Idaho and several other areas. Polyacrylamide, a very long chain polymer, increases aggregate stability and flocculates...

Sediment Entrapment by Stream Channel Vegetation
Degraded headwater streams are common in the mountainous West. They have experienced a variety of stresses from public and private uses and will require specific management consideration...

Pond Water, Sediment and Crystal Chemistry
The chemistry of pond waters is characterized with respect to TDS, major solute species and trace elements. Similar chemical characteristics are presented for pond bottom sediments as...

Stable Slopes of Alluvial Channels
An alluvial channel responds to the variation in the incoming sediment by changing its cross-section and especially the slope. Regime relations formulated by Lacey (1930) and many subsequent...

Sediment Yields from a Watershed in Taiwan
Characteristics of suspended sediment load were investigated for Shih-Men Reservoir watershed in Taiwan. Results of the investigation showed that annual suspended sediment load was correlated...

Hydraulic Desiltation for Noncohesive Sediment
Sedimentation reduces the useful life of a reservoir. The physical processes of flushing sediment are not well-understood. Flushing processes can be classified into two categories: local...

Optimization Modeling for Sedimentation in Alluvial Rivers Considering Uncertainties
A nonlinear optimization model is formulated for determining optimal reservoir releases to minimize channel bed aggradation and degradation in downstream rivers. The model is based upon...

Fundamental Principles of Tidal Wetland Restoration
Recognition of the vital role of tidal wetlands for sustaining migratory bird life, for indigenous animal habitat, and for the fishery of contiguous waters has stimulated efforts to restore...

Disaster Reduction in Dam and Reservoir Design
Disaster reduction for small- and medium-sized reservoir projects is considered for two specific types of dam failure: 1) during extremely high floods, and 2) when severe reservoir silting...

Total Sediment Loads of Tropical Rivers
Unmeasured and total sediment discharges were computed for 107 sets of data from the Amazon and Orinoco Rivers and their major tributaries. Unmeasured loads were generally small except...

Sedimentation and Flood Protection for the Lower Yellow River
The Lower Yellow River is known for its disastrous floods in the past. After 4 decades without major floodings, rapid economic and population growths along the River have drew concerns...

Surface Flows Over Intertidal Marshes
A marsh-flow measuring device has been designed to quantify the flow across the marsh surface. The fluorometric technique by tracking the visible substance (Rhodamine red dye) applied...

 

 

 

 

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