大清河北支“12·7”特大暴雨洪水流域产汇流参数变化分析

Watershed Runoff Parameter Analysis After July 21 Rainstorm Flood in the Northern Branch of Daqinghe River

2012年7月21日，海河流域大清河北支水系突降特大暴雨，大清河北支拒马河暴发洪水，拒马河上游张坊水文站最大流量2570m^3／s，南拒马河落宝滩水文站最大流量2520m3／s，洪水总量5000万m^3，经过40km下泄到北河店，北河店最大流量降至120m3／s，洪水总量I862万甜。通过对历史洪水分析，大清河北支流域河道产汇流参数发生了巨大变化，而产汇流参数的变化，直接影响着洪水计算结果。

On July 21,2012, heavy rainstorm hit the water system of the northern branch of Daqinghe River in Haihe River Basin. Floods occurred at the Jumahe River in the northern branch of Daqinghe River. The maximum flood flow at Zhangfang Hydrological Station in the upper reaches of the Jumahe River was 2 570 m3/s; the maximum flood flow at Luobaotan Hydrological Station in the southern Jumahe River was 2 520 m3/s with flood volume 50 million m3. When the flood went 40 km downwards to the Beihedian,its maximum flow reduced to120 ma/s,and the flood volume there was 18. 62 million m3. According to the analysis on historical floods, the tremendous changes of the parameters of runoff yield and flow concentration in the tributaries of the Daqinghe River took place, which could directly influence the calculated flood results.