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United States Department of Agriculture

Agricultural Research Service

Title: Using Temporally Limited Wind Data in the Wind Erosion Prediction System

Authors
item Skidmore, Edward
item Liao, Chaoying - NORTHWEST A&F UNIVERSITY
item Van Donk, Simon - FORMER ARS EMPLOYEE

Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 21, 2007
Publication Date: July 17, 2007
Citation: Skidmore, E.L., Liao, C. 2007. Using Temporally Limited Wind Data in the Wind Erosion Prediction System. Transactions of the ASABE. 51(5):1585-1590. Available: http://asae.frymulti.com/techpapers.asp?confid=min2007

Interpretive Summary: The Wind Erosion Prediction System (WEPS) requires hourly wind data but these are not always available. Therefore, a procedure was developed to stochastically generate wind speed and direction from temporally limited wind data. For three locations, two statistical datasets were created to be used with the WEPS stochastic wind generator, based on 1) the full dataset with 24 observations per day and 2) a subset of 4 observations per day: at 2, 8, 14, and 20 hours local time. Erosive wind power densities, calculated from both datasets, agreed well with each other. The same was true for prevailing wind erosion direction and WEPS-simulated soil loss. In spite of temporally limited wind data, it is possible to use WEPS to estimate wind erosion hazard and relative effectiveness of various conservation practices.

Technical Abstract: The Wind Erosion Prediction System (WEPS) is a daily time step computer model for the simulation of windblown sediment loss from a field. The model can be used to evaluate the effect of alternative cropping systems and management scenario’s on wind erosion. WEPS requires hourly wind data but these are not always available. Therefore, we investigated whether wind speed and direction can be simulated adequately from temporally limited data for use in WEPS. For three locations (La Junta, Colorado; Sidney, Nebraska; and Pendleton, Oregon), two statistical datasets were created to be used with the WEPS stochastic wind generator. The first was based on the full dataset with 24 observations per day and the second on a subset of 4 observations per day: at 2, 8, 14, and 20 hours local standard time. Erosive wind power densities, calculated from both datasets, agreed well with each other. The discrepancy was greatest for La Junta with a difference of 0.8 W m-2 (6%). Prevailing wind erosion direction and WEPS-simulated soil loss also showed good agreement between the two data sets. Many other subsets of two, three, and four measurements per day performed as well or better. In spite of temporally limited wind data, it is possible to use WEPS to estimate wind erosion risks and the effectiveness of various conservation practices. The results of this study allow one to evaluate whether limited data, measured at certain times of the day, are suitable for use in WEPS. For a new station, where only a few measurements per day are going to be made, they may be used as a guide to choose the times of the day to take these measurements.

Last Modified: 8/27/2014
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