Abstract
Wind rises particular strong in April and May at Okunakayama Highland, located in Northern Iwate, where wind erosion damages highland vegetables and crops. In order to realize actual situations of wind erosion, quantity of wind- drift soil particles, wind velocity and soil water content were observed during April and May for three years from 2005 to 2007. It was found that wind erosion occurred when soil water content fell below 28% and wind velocity reached 8m·s-1. Also soil water content fell to nearly 28% within three days after significant rainfall. Past occurrence situations of wind erosion was estimated by using the data of drought days and wind velocity, based on the weather data in April and May of past 30 years. It was found that wind erosion was the yearly event, especially it occurred between mid-April and beginning of May. Also found that the quantity of wind-drift soil particles increased between 11 am and 3 pm, and wind erosion rarely occurred in the morning, the evening and the mid-night.
