The Water Erosion Prediction Project: Erosion Processes
The erosion process on hillslopes is conceptualized in the USDA Water Erosion Prediction Project (WEPP) as being divided into rill and interrill processes. Rill detachment occurs when...
The Influence of Water Tables on Herbicide Losses
Atrazine and metolachlor were applied preemergent on April 22, 1987, to silage corn on high watertable fields which were either subsurface drained (104 mm drain tubes 1 m deep) or surface...
A Review of Water Table Management & BMP Effects on Selected Nitrogen Processes
This study addresses the combined impacts of water table management (WTM) and best management practices (BMP's) on surface and ground water quality. DRAINMOD (water table...
State Financing of Soil Conservation Programs
Federal financial incentives to implement conservation programs under traditional programs probably will not increase. Any increases in present financial incentives and new incentive alternatives...
What is Necessary to Forecast River Flows Reliably?
The problem of forecasting river flows employing conceptual rainfall-runoff models is reviewed stressing the important connections that exist among data requirements, model structure,...
IRSIS, A Software Package for Irrigation Scheduling
IRSIS (IRrigation Scheduling Information System) has been developed to solve problems concerning irrigation scheduling at field level. For a given climate, crop and field it offers the...
Biological Methods Petroleum Hydrocarbons Cleanup
Cleanup of the ground water and soils from hydrocarbon spills has mainly focused on air stripping and activated carbon for ground-water treatment, and vapor extraction and excavation followed...
The Formation of Meandering and Braided Channels
Flow in alluvial channels implies flow past boundaries that form and deform under the action of the flow. Interaction between the flow and the mobile boundaries produces channel patterns...
New Developments About Mud Transport Models. Application to a Macrotidal Estuary
In order to assess the fate of fine particles and adsorbed contaminants due to tidal forcing in estuaries, a mathematical modeling system for cohesive suspended matter transport and bottom...
Model Study of Side Slope Riprap
Laboratory experiments were conducted in 10-m long channels having 1.5 H : 1 V side slopes protected with a 20.7-mm diameter rock layer 1.5 diameters thick. Four models were tested. In...
Using Sediment-Threshold Theories in Waves and Currents
Fundamentally different threshold-of-motion theories were applied to sand transport in two different coastal environments. Several recommendations for threshold application were reached....
A Finite Element Application of Sand Terrace Formation Process
In this paper, the formation process of a sand terrace in front of river mouth is simulated numerically by means of the finite element method. The two-step explicit scheme is applied as...
Mid-Scale Laboratory Tests on a Two-Dimensional Movable-Bed Sand Model
A two-dimensional physical model was used to simulate wave-induced scour in front of a concrete dike sloped at 1:4. The tests were conducted at the U.S. Army Engineers Waterways Experiment...
Method to Predict Cropland Ephemeral Gully Erosion
The U.S. Soil Conservation Service (SCS) in cooperation with the Agricultural Research Service (ARS) has developed a microcomputer program to provide estimates of the average annual material...
Areal Sampling Techniques
Three areal methods, commonly used for sampling the coarser surface layer of gravel-bed streams, are examined. An idealized sediment deposit, that consists of cubic particles and accounts...
Sediment Transport Modelling from Grain Size Data
Grain-size analysis can be useful in determining some of the hydrodynamic aspects of the evolution of a natural sand body. The suite statistics approach minimizes single-sample anomalies...
The Relationship of Milligrams Per Liter to Parts Per Million
Derivations of the relationships between mg/l and ppm are presented. Although forms of these relationships can be found in scattered references, the author's intent is to...
Hyperconcentrations, Mud and Debris Flows?A Summary
Brief descriptions of the properties of mud and debris flow and hyperconcentrated stream flow materials and their importance to the descriptions and modeling of these flows are presented....
Relationship Between Channel Migration and Radius of Curvature on the Red River
The system behavior of meanders was investigated on the Red River between Shreveport, LA, and Index, AR. The effects of plan form geometry (r/w) and erodibility of bank material on the...
Exceedance of Allowable Velocity in Bank Stability
The authors have developed a method to account for flow duration in the application of the allowable velocity method through comparison with observed bank instabilities on a river system....
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