Abstract: In order to simulate the spatial distribution of complex terrain better,the 1∶250000 DEM (digital elevation model) was used with the help of ArcGIS. At the same time,precipitation was also taken into account. Due to the precipitation of different time had difference impacts on drought,so the key periods of precipitation was selected. Combined with the geographical factor,the regression-statistical model was established,which to simulate the spatial distribution of seasonal drought frequency in Chongqing. In order to verify the model,this article also used inverse distance square interpolation method to get the spatial distribution of drought frequency,which was used to compare the results of regression-statistical model with the observations. The compare results showed that the regression-statistical method considering geographical factor and precipitation was significantly better than the inverse distance square interpolation method,and could better reflect the spatial distribution trends of drought frequency over the rugged areas in Chongqing.

Key words: Drought, Drought, Spatial extension method, Rugged terrains, GIS, Chongqing