Crop water requirement isoline based on GIS and geostatistics

The water requirement isogram of the winter wheat in Shandong province could be mapped through many different interpolation methods by experimental data of the crop water requirement, which comes from "Data Base of National Irrigation Experimental Materials". The EXCELL of Microsoft and ARCGIS of ERIS were employed to combine organically the function of the space data management in GIS with that of the space analysis in Geostatistics. The result shows that the method of the Geostatistics is better than the conventional inverse distance weighting, the polynomial and the radial basis functions. That the five indexes in the Geostatistics, namely, the mean of the Ordinary Kriging spherical model, the Root-Mean-Square the Average Standard Error, the Mean Standardized, and the Root-Mean-Square Standardized are superior to the Ordinary Kriging exponential model, the simple Kriging spherical model and the Kriging exponential model with high precision.