NUMERICAL SIMULATION OF THE SURFACE RADIATION FIELD IN A HILLY COUNTRY^*

Based on the simulations of the topographic parameters(mean orientation,slope,and terrain screen angle)in a hilly land,discussion is made term by term of the technique for modelling of all components is done in the surface radiation balance over a rugged terrain,thus presenting a computer model for each component.In terms of experimental data,the components is calculated for the mesh grids of 100m×100 m each over 3.0×3.5 km2 in the Zhaogongling,southern Dabie Mountains and a map is prepared showing the distribution of these components for January and July.Results show that the hilly-land surface radiation field matches the terrain element field quite well,which reveals the determining function of the latter,with orientational effect dominant in winter and terrain screen effect most significant in summer.The simulation technique presented is in principle applicable to the calculation for a radiation field in any kind of topography,thus providing a means for further exploration of hilly-land climate resource.