Study on the method of GIS based spatial interpolation of climate factors in China

Annual average temperature data, annual rainfall and annual accumulated temperature data from 2114 meteorological stations in China and surrounding countries from 1961 to 1990 were interpolated by using inverse distance weighing (IDW), ordinary kriging (OK) and spline with ArcMap. Crossvalidation was applied to evaluate the three interpolation methods. The result indicated that the precision of interpolation results were varied significantly along with the number of selected meteorological stations for interpolating. For the three climate factors, ordinary Kriging shown the best precision. For annual average temperature and annual rainfall, spline shown better result than IDW, but for annual accumulated temperature, IDW was better than spline. The research indicated that the spatial distribution of moisture and temperature in China shown an obvious westeast, southnorth line as same with the HU population line. In the west of this line, the moisture and temperature conditions were poor and in the east of this line, the conditions were good.