HEC-HMS模型在城市化流域洪水模拟中的应用

流域城市化过程影响了城市洪水形成的产汇流条件,显著增大了流域洪水模拟预报难度。采用HECHMS水文模型,选取秦淮河流域城市化前1980~1988年间共8场降雨-径流过程、城市化后2007~2013年间共7场降雨-径流过程开展洪水模拟研究,率定城市化前后不同土地利用情景下的产汇流参数,并设计城市化影响洪水模拟方案,对比分析城市化影响下的流域水文响应。结果表明:HEC-HMS模型在秦淮河流域城市化前后均具有很好适用性,且单峰洪水过程模拟精度高;城市化后流域内其他用地向城市建设用地转移,流域内不透水面积增加明显,使得产流量增加,洪峰流量增大,峰现时间提前约2 h。

Flood simulation of typical urbanized watershed by HEC-HMS model

The basin urbanization can affect flood formation and confluence and significantly increase the difficulty in flood forecasting. In this paper, the HEC-HMS hydrological model is used to simulate the selected eight rainfall-runoff processes from 1980 to 1988 before urbanization in Qinhuai River Basin and seven rainfall-runoff processes from 2007 to 2013 after urbanization. Flood formation and confluence parameters under different land use scenarios were calibrated and the flood simulation schemes before and after urbanization were put forward for the analysis of watershed hydrological response to urbanization. The results show that the HEC-HMS model has good applicability in Qinhuai River Basin before and after the urbanization, and the simulation accuracy of the single-peak flood process is high. After the urbanization, other land use in watershed was transferred to urban construction land, so the watershed impermeable area increased significantly, leading to the increase of runoff and flood peak and 2 hours ahead of flood peak arriving.