The basin Yan-Shoei creek is chosen as the study area to investigate the influence of urbanizing on runoff hydrograph and flood storage ability, which are the subject we concern. To mitigate the influence of land use change, the non-structure flood mitigation method is proposed. 1972 LANDSAT MSS and 2000 SPOT satellite imageries are applied to identify the land use types by using unsupervised, supervised classification methods and the method that the image was classified by supervised classification after the thematic maps were first cut off. We found the last method has the best
result. The building area increases about 1600 acres from 1972 to 2000.
