Spatial interpolation of precipitation considering geographic and topographic influences - A case study in the Poyang Lake Watershed, china

Precipitation is important in many fields. It is meaningful and valuable to estimate the spatial distribution of precipitation. However, existing methods introduced for precipitation interpolation are not satisfactory. In this paper, geographic and topographic factors are taken into consideration and put into Cokriging method to interpolate the precipitation maps of annual precipitation in Poyang Lake Watershed of China. At the same time, IDW (Inverse distance weight) method, Ordinary Kriging method and Cokriging method considering elevation only has been used to interpolate the precipitation. Evaluating by MAE (mean absolute error), MRE (mean relative error), as well as RMSIE(Root mean squared interpolation error). The results indicate that Cokriging method considering geographic and topographic facotors is suoprior than IDW method and Cokriging method considering elevation only, and it has no obvious advantage compared with ordinary Kriging method.