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...

Neutron Gauge Calibration Comparison of Methods
Several methods for obtaining soil samples for determining soil water content were used for field calibration of neutron gauges. This paper compares the results of calibration curves obtained...

Effect of Moisture and Bulk Density Sampling on Neutron Moisture Gauge Calibration
Three moisture and bulk density sampling methods were evaluated for use in neutron gauge calibration. Each of the methods was comprised of a single core or portions of a core taken during...

Multiquadrics in Engineering Modeling
The theory of multiquadrics (MQ) is advancing rapidly and it is usable today. When appropriate MQ can accurately interpolate for unknown values with less computational cost than Kriging....

Evapotranspiration of Dry Beans with Drip Irrigation
Information about the effect of irrigation on dry bean production in the Southwestern Colorado is very limited. The primary objective of this study is to establish a crop water use (ET)...

Computing in Civil and Building Engineering
This proceeding consists of papers presented at the Fifth International Conference on Computing in Civil and Building Engineering held in Anaheim, California, June 7-9, 1993. The proceedings...

Concentration History During Pumping from a Leaky Aquifer with Stratified Initial Concentration
Analytical and numerical solutions are employed to examine the concentration history of a dissolved substance in water pumped from a leaky aquifer. Many aquifer systems are characterized...

Parameter Estimates for a Groundwater Model
This paper presents a parameter sensitivity study of a two dimensional flow and transport model of a contaminated site. Hydrogeological and site data from previous investigations were...

Simulation of Buoyant, Miscible Liquid Plumes in Heterogeneous Aquifers
Laboratory experiments have been conducted in a sand tank with a single heterogeneity into which NaNO3 is continuously injected. From samples along, across and over the depth of the tank...

An Overview of Methods to Delineate Capture Zones of Pumping Wells
Rainfall over the surface area of an unconfined aquifer, which contributes flow to a pumping well under Dupuit conditions, was estimated. Using a two-dimensional analytical model with...

Nonlinear Hydrodynamic Pressures on Dam Faces with Arbitrary Reservoir Shapes
A finite-difference method was used to calculate the nonlinear hydrodynamic pressures acting on the rigid dam faces during earthquakes. The geometry of the reservoir is in a realistic...

Watershed Erosion
Scientific agricultural planning requires knowledge of the relations between soil and water that cause soil loss, and of the procedure to reduce such losses on cropland. This paper presents...

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...

 

 

 

 

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