STOCHASTIC WIND SIMULATION FOR EROSION MODELING

The purpose of this study was to develop a wind simulator to furnish wind direction and sub-hourly wind speed to users of wind speed information, particularly for wind erosion modeling. We analyzed the Wind Energy Resource Information System data to determine scale and shape parameters of the Weibull distribution for each of the 16 cardinal directions for each month at 704 locations in the United States. We also summarized wind direction distributions, ratio of daily maximum to daily minimum wind speed, and hour of maximum wind speed by month for each location. This summary of historical wind statistics constitutes a compact data base for wind simulation. Equations were formulated and procedures developed and used with the compact data base and a random number generator to simulate wind direction and sub-hourly wind speed. Cumulative wind speed distributions, calculated from the Weibull parameters, and wind speeds simulated at one-hour intervals for 1000 days agreed well. The model reflects historical day-to-day wind variation and wind speed variations within a day. It will be useful to those needing wind speed and wind direction information and will provide the wind simulator requirements in a wind erosion prediction system.