Research On Small Watershed Classification And Early-Warning Indicators Of Flash Flood Disasters In Prevention Areas

Watershed precipitation characteristics and underlying surface conditions are the main influencing factors of the forming and occurring of mountain flood disasters. Based on the rainstorm and run-off district classification of Shandong Hydrologic Atlas, firstly this thesis taking the typical counties of prevention areas as researching objects, summarized the historical disaster statistics from aspects of their occurrence time, occurrence types, disaster types and disaster causes, and worked out the forming factors and characteristics of different regions. Furthermore, we analyzed the characteristics of every single small watershed of prevention areas, including geometric features, landform, soil type, land use type and human activities.Basing on the three similar elements such as climate, underlying surface and hydrological response relationship, we built the hydrological similarity factor according to the structural characteristics of small watersheds, and respectively used clustering methodology and hydrological response model parameter method divided the watersheds in Licheng District into 4 types:hilly region, sub-hilly region, plain area, similar-plain area. We analyzed their main characteristics and then studied hydrological parameter determination method and runoff forming regular, so as to figure them out in small watersheds of no data areas using hydrologic comparison method or interpolation.At last, we chose three typical watersheds to analyze the applicability of model in the aspects of model construction, parameter alibration result assessment. Then we used the HEC-HMS model to accomplish the of typical hilly region and sub-hilly region small watershed in Wohushan Reservoir Watershed and studied the determination method of early warning indicators based on the hydrological models.