Spatio-temporal Variation of Erosive Precipitation in Loess Plateau during Past 50 Years

In this study,the spatio-temporal variations of annual precipitation,erosive precipitation and rainstorm over the Loess Plateau were investigated on the basis of the observed data of daily precipitation at 99 stations for the period 1956-2005.The annual precipitation showed a decreasing trend over the Loess Plateau in the past 50 years.The significant decreasing region mainly appeared in the middle Huanghe(Yellow) River,especially in the Wuding River basin,the Fenhe River basin and the northern and central Shanxi Province,where the annual precipitation and erosive precipitation decreased more than 10%.Rainstorm variation showed a notable spatio-temporal difference in the Loess Plateau and an decreasing zone range from Shuozhou,Lishi,Linfen to Sanmenxia,where rainstorm have descended more than 20%.In the past 20 years,the annual precipitation had a significant decreasing trend over the Loess Plateau,whereas the decreasing of erosive precipitation was more intensive than annual precipitation variations and rainstorm changes more intensively than the erosive precipitation.