Study on the Feasibility of PRISM in Spatial Interpolation of Rainfall in Complex Terrain

JIANG Yuhao;LIU Pengju;XIA Zhiwu;XU Dengping;LIU Changchun;Research Institute of Resource Information Techniques,Chinese Academy of Forestry;Foresty Bureau of Xiangtan Country;Academy of Forest Inventory and Planning,SFA;

PRISM;;complex terrain;;DEM;;rainfall;;spatial interpolation

Rainfall is one of the important forestry meteorological data,and how to obtain high-precision rainfall data in complex terrain environment is of great significance for the study of forest ecology and environment.Considering the impact brought by elevation,slope and distance factors,a new meteorology based on PRISM was supposed to interpolate the spatial distribution of rainfall with DEM and data of automatic weather stations in northwest of Beijing,and output the results in GDAL.We used the method of cross-validation to validate the precision of results,and the MAE is 1.68 mm,RMSE is 2.26 mm,while the interpolation precision of high altitude is less than that of the low altitude.To further demonstrate the superiority of PRISM,the results were also compared with common methods,such as IDW,Kriging,Spline and Trend.The results showed most of the results obtained by interpolation methods had shown that rainfall increased with elevation,and the results of PRISM were the most detailed,while the results of IDW and Kriging come next,but Spline was poor,or even had negative values.As for trend,the results were ordinary,and lacked of the detail.Compared with data of seven verification stations,the conclusion further illustrated that the results of PRISM were closer to the field measured data.These results showed that PRISM was more accurately than other interpolation methods to express the spatial distribution of rainfall under the complex terrain conditions,.