2.1 Hydrological analysis

Logically，catchment，river network，and corresponding attributes arethe main elements we should obtain before we can set up a hydrological model.The flow chart of hydrologic analysis can be shown in Figure 2-1.In distributed hydrological modeling，the first thing is hydrological analysis that ismainly the terrain preprocessing and watershed processing.It enables us to obtain basin scale digital information from original digital elevation model，DEM.Thus，GIS tools should be used for calculation.DEM is the only rawmaterial that can be used to extract simulated river network and for successivecatchment delineation.Although DEM has general image of terrain，the rivernetwork extracted from it may still be different from reality meaning that westill need measured river network for modi ......     （共7889字）    [阅读本文]>>