Comparison of Four Precipatation Spatial Interpolation Methods in Gansu

Spatial interpolation of climate data is very important to those areas where the meteorological stations are rare and its distribution is unreasonable. Four methods Kriging、IDW、Spline and Trend were used to interpolate precipatation in Gansu province .The results presented that Kriging method was the best one for spatial interpolation .From the spatial distribution of precipation map obtained by Kriging in Gansu province ,we can see that the rainfull increased from southeast to northwest and that in the summer and autumn is much more than that in other seasons.