Characteristics of Heavy Rainfall by Typhoon 9709 in the Northern Part of Yamaguchi Prefecture and Rice Damage with Accumulation of Earth and Sand by Bank Collapse of Farm Pond

Abstract

Agricultural damage was caused by heavy rainfall during typhoon 9709 in the northern part of Yamaguchi Prefecture and the western part of Shimane Prefecture.In Mutsumi village, the amount of precipitation measured by five automatic weather stations from July 26 to 28 was 582∼782m, and the amount of precipitation on July 27 was 429∼547mm.We had more rainfall in Mutsumi village than registered at the observation station(AMeDAS)of the meteorological agency.A farm pond in collapsed four places due to the heavy rainfall at Mutsumi village.At the Asou farm pond, rice plants were buried by earth and sand because of bank collapse.The relationships between accumulation depth of earth and sand and top dry weight and grain weight were approximated by a second-order equation.In this case, the accumulation depth of earth and sand was 50cm and top dry weight was zero.In this case of a depth of 35cm, grain weight was zero.