Sophisticated Computer Tools for Water Management
Sophisticated new computer tools were applied to develop a water management plan for Nassau County, Long Island. A regional groundwater flow model and two 3-dimensional saltwater intrusion...

Transfer Function Modeling of Evapotranspiration
The correct estimation of evapotranspiration is a fundamental step in planning, design and operation of most water resources projects. The dependence on various climatological parameters...

Sustained Yield of the Provo Groundwater Basin
The sustained yield of the Provo Groundwater Basin has been determined by a correlation analysis of the change in groundwater levels with the April-October stream flow at the mouth of...

Acidity and Chemistry of Arizona's Snowpacks
Acid snow, the frozen version of the acid rain phenomena, has been sampled in several western states, e.g., California, Nevada, Montana, and Oregon. Measurements of snowpack acidity in...

Parameter Sensitivity of a Non-Linear, Process-Based Soil Erosion Model
Process-based, parameter distributed models have become widely accepted tools to predict the impacts of land use changes. Unfortunately these computer models are becoming more complex...

Chaos Characteristics of Tree-Ring Series
Thirteen tree-ring series from the Salt and Verde River basins in Arizona are studied to distinguish between chaos and randomness. A chaotic moving average model that represents the time...

Probabilistic Characteristics of Elapsed Time Between Rainfalls
The elapsed time between rainfalls is analyzed statistically using the hourly rain data at two locations: the flat-plain at Urbana, Illinois and the northwestern Appalachian foothills...

Analysis of Spatial and Temporal Precipitation Data Over a Densely Gaged Experimental Watershed
Historical precipitation data from the densely gaged Walnut Gulch Experimental Watershed in southeastern Arizona are used to quantify watershed-scale properties of precipitation. Daily,...

Watershed Simulation for Characterizing Droughts Under the Influence of Climate Change
The paper describes a model for simulating soil moisture deficit on a daily basis using historical rainfall and climatic data for the analysis of droughts. Distributed parameter hydrologic...

Application of Distributed Parameter Watershed Model for Determining the Effects of Climate Change on Water Resources
Projected scenarios of climate change are likely to have significant effects on hydrology and water resources in the semi-arid western United States. The paper describes the application...

Irrigation Lettuce with Buried Drip, Surface Drip, and Furrow Irrigation: Spatial Variability of Plants, Soil, and Water
Spatial variability of plant growth, soil, and water was investigated for a furrow, surface drip, and subsurface drip irrigation systems. Variability was analyzed by sampling plant weight,...

Selenium in Soil, Water, Sediment, and Biota of the Lower Sun River Area, West-Central Montana
A U.S. Department of the Interior study started in 1990 examined the source, movement, fate, and possible biological effects of selenium associated with irrigation drainage from the Sun...

Estimating ET Using Turbulent Coherent Structures
Two methods for estimating sensible heat flux to use in energy balance equations for computing crop evapotranspiration are discussed. The methods use high frequency temperature measurements...

Growing Season Evapotranspiration and Crop Coefficient
The Bowen ratio-energy balance (BREB) method was used to continuously estimate 20-minute actual evapotranspiration (ETa) in the middle of a 36-ha...

Hourly Reference Evapotranspiration by Bowen Ratio and Penman Methods
Hourly and daily reference evapotranspiration (ETo) computed from Bowen ratio energy balance (BREB) measurements were compared with ETo estimated from the hourly Penman equation (ETP)....

Revision of Oregon Crop Water Use and Irrigation Requirements
A project to revise the crop water use estimates and irrigation requirements for the state at Oregon is described. The FAO modified Blaney-Criddle method was applied in this project since...

Soil Bulk Density Sampling for Neutron Gauge Calibration
The ASCE Task Committee on Neutron Gauge Calibration met in Logan, Utah in July 1992 to investigate the various methods of soil sampling, installation of access tubes, effect of various...

Measuring Soil Bulk Density Profiles with a Single Probe Gamma Density Gauge
Calibrating neutron depth gauges for measuring soil water content profiles requires soil bulk density data. In this study, the feasibility of using a single probe gamma density gauge to...

Error Analysis of Bulk Density Measurements for Neutron Moisture Gauge Calibration
Six bulk density sampling methods were evaluated for use in neutron gauge calibration. All six methods provided estimates of bulk density which were generally within 5% of bulk density...

Performance Factors of Neutron Moisture Probes Related to Position of Source on Detector
The performances of two commercially available neutron moisture probes with different source-detector placement were evaluated. The probes were the Troxler with the neutron source placed...

 

 

 

 

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