Comparative Study on the Spatial Variability of Rainfall and Its Spatial Interpolation Methods

In order to compare the advantages and disadvantages of the spatial interpolation methods of rainfall spatial variation studies, rainfall interpolation and spatial field variation are analyzed by using reverse-distance weighing method, trend surface fitting, sampling strip interpolation method, ordinary Kriging method and universal Kriging method with a target study of Wuding River Basin. As for the ordinary Kriging technique, the rainfall semi-variation function agrees well with the shape of sphere model. Through comparing the results of continuous spatial distribution of the interpolation methods with those of the actual observation, it is indicated that there is no significant differences between the results of the interpolation methods, the results of ordinary Kriging method and reverse-distance weighing method can obtain the better integer effect, especially that of the ring model of ordinary Kriging method the best. The spatial interpolation and mapping for the rainfall in the basin are also conducted by using the interpolation methods mentioned above.