| Based on the precipitation data of 60 meteorological stations between March ～ October in Gansu Province from 1961 to 2004,rainfall and days of light rain,moderate rain,heavy rain,torrent rain and times of successive rain days in March ～ October were calculated,and response of arid meteorological disaster to variation of different intensity precipitation days were analyzed.The results are as follows: there has been a decrease in rainfall,days of light rain,moderate rain,heavy rain and torrent rain,and times of successive rain,while the drought area and the grain reduction have increased;rainfall and moderate rain days and times of successive rain have a much closer negative correlation with drought area and grain reduction than light rain and heavy rain do.Decreases of successive rain times and moderate rain days are important factors that enlarged the drought area and resulted in a considerable decrease in grain production. |