Study On The Distribution Of The Rainfall Over Watershed In The Loess Region Of West Shanxi

Based on Geostastics the density and distribution of rain gauge..,distribution of rainfall ,and center of rainfall have been studied in this artic.According to the principle of spatial autocorrection,the author advances that the rain gauge shoud be builded along with the shape of watershed and the distance between these be 0.5km-1km. Author correct this theory using the spatial interpolation of litter gauge and found that the distribution of rainfall can be exactly reflected when the distance of rain gauge is not beyond 2km and lots of information is lost and the grid can only explain the tendency when the distance of rain gauge is beyond 2km..The grid of rainfall produced on the data of rain gauge whose distance are aroud 1km shows that the distribution of rainfall change greatly in the Loess region of west Shanxi,The max is five time more than min.The center of rainfall is not obvious in the watershed,the region of max rainfall tranverse the boundary of watershed and occured in different places ,so the center of rainfall is distributed in larger criterion,and happens occacionly.