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...
Locating and Sizing Air Release Valves on Irrigation Systems
This writing is directed to persons involved in irrigation systems and describes the usage of air release and vacuum valves. Principles described are applicable to many other piping systems,...
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,...
Computer Control of Houston's Water System
The City of Houston's Central Surveillance and Control System utilizes dual host computers and over 100 'smart' Remote Terminal Units to control...
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...
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