If there is no resource or sink in the coarse grid block, the numerical computing method of effective permeability of coarse grid blocks has been given,where the fluid flow rate is the same flowing through the coarse grid block as all fine grid blocks in the coarse grid.

if there are not resource or sink in the coarse grid blocks,the 3D solution of the fine grid blocks has been obtained by solving 3D fluid equations in porous media with direct method,and then the effective permeability of coarse grid blocks has been computed by the 3D solutions.

Where the permeability or porosity change is abnormal, the fine grid blocks are automatically adopted and the 3D fluid equations in porous media is solved by the direct method.

Based on the principle of climatology and the observed meteorological and hydrological data (1971-2000) , statistics and spline methods were used to establish the models of calculating agricultural climatic elements in fine grids of 100×100 meters under the support of RS (Remote Sensing) , GIS (Geographical Information System) and computer s technology.