Flood Process Simulation in a Karst Landform Watershed
Karst landform has a disturbance effect on the process of runoff generation and flow concentration,resulting in gener-ally low accuracy of flood forecasting.The karst hydrological model was established based on the distribution curve of water hold-ing capacity of karst units.The runoff generation in karst area was divided into fast karst flow and slow karst flow,and the flow concentration calculation was carried out to enter the river network respectively.Coupled with the three-water sources Xin'anjiang model,a flood forecast model that was suitable for the underlying surface conditions of karst landform was established.The water-shed above Yangchang hydrological station of Sancha River in Guizhou province was selected as the study area,and the sub-watershed units were divided to test the application effect of the model in the simulation of the flood processes.The results show that among the 20 floods simulated by the Xin'anjiang karst model,16 floods meet the allowable error requirements of flood peak,flood volume and peak occurrence time forecast,with the qualified rate reaching 80％and the average deterministic coeffi-cient being 0.68.Compared with the original Xin'anjiang model,the improved model considering the influence of karst conditions has better accuracy for the simulation of the flood processes.
karst watershedXin'anjiang karst modelWater holding capacity of karst areaflood simulation
万方数据
维普
