An Interactive Microcomputer Program for One-Dimensional Solute Transport in Saturated Soil-Water Systems
This paper presents a user-friendly microcomputer program for one-dimensional solute transport in saturated soil-water systems. Eight different types of adsorption isotherms, ranging from...

The MSU Sprinkling Infiltrometer: A Device to Measure Time-to-Ponding
Time-to-ponding can be determined quickly and with minimal disturbance to the soil surface by the use of a sprinking infiltrometer developed at Michigan State University (MSU). Solenoid...

Effective On-Farm Irrigation Scheduling in the Humid Southeast
An extension demonstration of a checkbook type irrigation scheduling system using a personal computer and spread sheet is described. The system incorporates typical crop water use curves,...

The Water Erosion Prediction Project: Model Overview
A new generation of water erosion prediction technology is being developed by the USDA Water Erosion Prediction Project (WEPP). The WEPP models are a new erosion prediction technology...

The Water Erosion Prediction Project: Erosion Parameter Estimation
The USDA Water Erosion Prediction Project (WEPP) includes a large field program for collection of experimental data to evaluate soil erodibility. Rainfall simulation techniques are used...

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...

Derivation of a Stability Principle from the Shields Criterion
The widely used specific energy equation, which defines the subcritical and supercritical states of the open channel flow, is a direct result of the integration of the Froude number corresponding...

Self-Accelerated Turbidity Current Prediction Based Upon Dynamic Turbulence Models
The structure of a self-accelerated turbidity current appears to be significantly better predicted by a dynamic Reynolds stress turbulence model than by one- and two- equation models....

Modeling Sediment Transport in Rectangular Ducts with a Two-Equation Model of Turbulence
The paper deals with the application of a two-equation model of turbulence to the calculation of flows in rectangular ducts. A non-linear relationship is used to link the Reynolds stresses...

Mathematical Models for Turbulent Shear Stress in Sediment-Laden Flows
Turbulent shear stress in sediment-laden flows has been examined by several investigators including H.A. Einstein and N. Chien A. Zagustin and J.C. Willis. Three derivations resulted in...

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....

 

 

 

 

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