THE WALNUT GULCH RAINFALL SIMULATOR: A COMPUTER-CONTROLLED VARIABLE INTENSITY RAINFALL SIMULATOR

2004 ◽  
Vol 20 (1) ◽  
pp. 25-31 ◽  
Author(s):  
G. B. Paige ◽  
J. J. Stone ◽  
J. R. Smith ◽  
J. R. Kennedy
Keyword(s):  
Variable Intensity ◽  
Rainfall Simulator ◽  
Computer Controlled ◽  
Walnut Gulch

scholarly journals Development and testing of a large, transportable rainfall simulator for plot-scale runoff and parameter estimation

2014 ◽  
Vol 18 (10) ◽  
pp. 4169-4183 ◽  
Author(s):  
T. G. Wilson ◽  
C. Cortis ◽  
N. Montaldo ◽  
J. D. Albertson
Keyword(s):  
Hydraulic Conductivity ◽  
Overland Flow ◽  
Field Tests ◽  
Soil Surface ◽  
Saturated Hydraulic Conductivity ◽  
Water Retention Curve ◽  
Soil Water Retention Curve ◽  
Soil Water Retention ◽  
Variable Intensity ◽  
Rainfall Simulator

Abstract. There is increased interest in the interplay between vegetation conditions and overland flow generation. The literature is unclear on this relationship, and there is little quantitative guidance for modeling efforts. Therefore, experimental efforts are needed, and these call for a lightweight transportable plot-scale (>10 m2) rainfall simulator that can be deployed quickly and quickly redeployed over various vegetation cover conditions. Accordingly, a variable-intensity rainfall simulator and collection system was designed and tested in the laboratory and in the field. The system was tested with three configurations of common pressure washing nozzles producing rainfall intensities of 62, 43, and 32 mm h-1 with uniformity coefficients of 76, 65, and 62%, respectively, over a plot of 15.12 m2. Field tests were carried out on a grassy field with silt–loam soil in Orroli, Sardinia, in July and August 2010, and rainfall, soil moisture, and runoff data were collected. The two-term Philip infiltration model was used to find optimal values for the saturated hydraulic conductivity of the soil surface and bulk soil, soil water retention curve slope, and air entry suction head. Optimized hydraulic conductivity values were similar to both the measured final infiltration rate and literature values for saturated hydraulic conductivity. This inexpensive (less than USD 1000) rainfall simulator can therefore be used to identify field parameters needed for hydrologic modeling.

scholarly journals Rainfall simulation experiments in the Southwestern USA using the Walnut Gulch Rainfall Simulator

2017 ◽  
Author(s):  
Viktor Polyakov ◽  
Jeffry Stone ◽  
Chandra Holifield Collins ◽  
Mark A. Nearing ◽  
Ginger Paige ◽  
...  
Keyword(s):  
Ground Cover ◽  
Rainfall Simulation ◽  
Supplementary Information ◽  
Simulation Experiments ◽  
Data Set ◽  
Rainfall Simulator ◽  
Ecological Sites ◽  
Erosion Rates ◽  
Southwestern Usa ◽  
Walnut Gulch

Abstract. The dataset contains hydrological, erosion, vegetation, ground cover, and other supplementary information from 272 rainfall simulation experiments conducted on 23 semi-arid rangeland locations in Arizona and Nevada between 2002 and 2013. On 30 % of the plots simulations were conducted up to five times during the decade of study. The rainfall was generated using the Walnut Gulch Rainfall Simulator on 2 m by 6 m plots. Simulation sites included brush and grassland areas with various degree of disturbance by grazing, wildfire, or brush removal. This dataset advances our understanding of basic hydrological and biological processes that drive soil erosion on arid rangelands. It can be used to quantify runoff, infiltration, and erosion rates on a variety of ecological sites in the Southwestern USA. Inclusion of wildfire and brush treatment locations combined with long term observations makes it important for studying vegetation recovery, ecological transitions, and effect of management. It is also a valuable resource for erosion model parameterization and validation. The data set available from the National Agricultural Library at https://data.nal.usda.gov/search/type/dataset (https://doi.org/doi:10.15482/USDA.ADC/1358583).

scholarly journals Development and testing of a large, transportable rainfall simulator for plot-scale runoff and parameter estimation

2014 ◽  
Vol 11 (4) ◽  
pp. 4267-4310
Author(s):  
T. G. Wilson ◽  
C. Cortis ◽  
N. Montaldo ◽  
J. D. Albertson
Keyword(s):  
Hydraulic Conductivity ◽  
Overland Flow ◽  
Field Tests ◽  
Soil Surface ◽  
Saturated Hydraulic Conductivity ◽  
Water Retention Curve ◽  
Soil Water Retention Curve ◽  
Soil Water Retention ◽  
Variable Intensity ◽  
Rainfall Simulator

Abstract. There is increased interest in the interplay between vegetation conditions and overland flow generation. The literature is unclear on this relationship and there is little quantitative guidance for modeling efforts. Therefore, experimental efforts are needed and these call for a lightweight transportable plot-scale (>10 m2) rainfall simulator that can be deployed quickly and quickly redeployed over various vegetation cover conditions. Accordingly, a variable intensity rainfall simulator and collection system was designed and tested in the laboratory and in the field. The system was tested with three configurations of common pressure washing nozzles producing rainfall intensities of 62, 43, and 32 mm h−1 with uniformity coefficients of 76, 65, and 62, respectively, over a plot of 15.12 m2. Field tests were carried out in on a grassy field with silt-loam soil in Orroli, Sardinia in July and August 2010, and rainfall, soil moisture, and runoff data were collected. The two-term Philip infiltration model was used to find optimal values for the saturated hydraulic conductivity of the soil surface and bulk soil, soil water retention curve slope, and air entry suction head. Optimized hydraulic conductivity values were comparable to both the measured final infiltration rate and literature values for saturated hydraulic conductivity. This inexpensive rainfall simulator can therefore be used to identify field parameters needed for hydrologic modeling.

scholarly journals Rainfall simulation experiments in the southwestern USA using the Walnut Gulch Rainfall Simulator

2018 ◽  
Vol 10 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Viktor Polyakov ◽  
Jeffry Stone ◽  
Chandra Holifield Collins ◽  
Mark A. Nearing ◽  
Ginger Paige ◽  
...  
Keyword(s):  
Ground Cover ◽  
Rainfall Simulation ◽  
Supplementary Information ◽  
Simulation Experiments ◽  
Rainfall Simulator ◽  
Ecological Sites ◽  
Erosion Rates ◽  
Model Parameterization ◽  
Southwestern Usa ◽  
Walnut Gulch

Abstract. This dataset contains hydrological, erosion, vegetation, ground cover, and other supplementary information from 272 rainfall simulation experiments conducted on 23 semiarid rangeland locations in Arizona and Nevada between 2002 and 2013. On 30 % of the plots, simulations were conducted up to five times during the decade of study. The rainfall was generated using the Walnut Gulch Rainfall Simulator on 2 m by 6 m plots. Simulation sites included brush and grassland areas with various degrees of disturbance by grazing, wildfire, or brush removal. This dataset advances our understanding of basic hydrological and biological processes that drive soil erosion on arid rangelands. It can be used to estimate runoff, infiltration, and erosion rates at a variety of ecological sites in the Southwestern USA. The inclusion of wildfire and brush treatment locations combined with long-term observations makes it important for studying vegetation recovery, ecological transitions, and the effect of management. It is also a valuable resource for erosion model parameterization and validation. The dataset is available from the National Agricultural Library at https://data.nal.usda.gov/search/type/dataset (DOI: https://doi.org/10.15482/USDA.ADC/1358583).

Computer-Controlled Variable Intensity Rain Simulator

1997 ◽  
Vol 61 (4) ◽  
pp. 1182-1189 ◽  
Author(s):  
R. J. Lascano ◽  
J. T. Vorheis ◽  
R. L. Baumhardt ◽  
D. R. Salisbury
Keyword(s):  
Variable Intensity ◽  
Computer Controlled ◽  
Rain Simulator

SPECTRA: A program for processing electron images of crystals

1992 ◽  
Vol 50 (1) ◽  
pp. 132-133
Author(s):  
M.F. Schmid ◽  
R. Dargahi ◽  
M. W. Tam
Keyword(s):  
Lattice Distortion ◽  
Data Transfer ◽  
Reciprocal Lattice ◽  
Data Entry ◽  
Image Data ◽  
Distortion Correction ◽  
Specimen Preparation ◽  
Electron Image ◽  
Computer Controlled ◽  
Program Modules

Electron crystallography is an emerging field for structure determination as evidenced by a number of membrane proteins that have been solved to near-atomic resolution. Advances in specimen preparation and in data acquisition with a 400kV microscope by computer controlled spot scanning mean that our ability to record electron image data will outstrip our capacity to analyze it. The computed fourier transform of these images must be processed in order to provide a direct measurement of amplitudes and phases needed for 3-D reconstruction.In anticipation of this processing bottleneck, we have written a program that incorporates a menu-and mouse-driven procedure for auto-indexing and refining the reciprocal lattice parameters in the computed transform from an image of a crystal. It is linked to subsequent steps of image processing by a system of data bases and spawned child processes; data transfer between different program modules no longer requires manual data entry. The progress of the reciprocal lattice refinement is monitored visually and quantitatively. If desired, the processing is carried through the lattice distortion correction (unbending) steps automatically.

Applications of CCEM to Environmental Health Problems

1985 ◽  
Vol 43 ◽  
pp. 102-103
Author(s):  
R. J. Lee ◽  
J. S. Walker
Keyword(s):  
Electron Microscopy ◽  
Image Analysis ◽  
Environmental Health ◽  
Computer Control ◽  
External Agent ◽  
External Agents ◽  
Computer Controlled ◽  
Primitive State ◽  
Textural Changes ◽  
General Aspects

Electron microscopy (EM), with the advent of computer control and image analysis techniques, is rapidly evolving from an interpretative science into a quantitative technique. Electron microscopy is potentially of value in two general aspects of environmental health: exposure and diagnosis.In diagnosis, electron microscopy is essentially an extension of optical microscopy. The goal is to characterize cellular changes induced by external agents. The external agent could be any foreign material, chemicals, or even stress. The use of electron microscopy as a diagnostic tool is well- developed, but computer-controlled electron microscopy (CCEM) has had only limited impact, mainly because it is fairly new and many institutions lack the resources to acquire the capability. In addition, major contributions to diagnosis will come from CCEM only when image analysis (IA) and processing algorithms are developed which allow the morphological and textural changes recognized by experienced medical practioners to be quantified. The application of IA techniques to compare cellular structure is still in a primitive state.

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