陆气耦合模型在实时暴雨洪水预报中的应用

Application of a coupled atmospheric-hydrological modeling system to real-time flood forecast

采用加拿大区域性中尺度大气模式MC2（Canadian Mesoscale Compressible Community）和新安江模型单向耦合模型系统，对2005年7月4～15日发生在淮河流域的一场暴雨洪水，进行了实时预报。采用王家坝以上流域的实测降水和王家坝断面的实测洪水资料，对MC2预报降水的时空分布和陆气耦合模型预报的洪水过程进行了分析。结果表明，MC2对该场强降水过程具有很好的预报能力，陆气耦合模型有效地增长了洪水预报的预见期，具有很好的应用前景。

A coupled atmospheric-hydrological modeling system is established over the Huaihe River Basin for predicting severe precipitation and real-time flood forecast. This system is the high-resolution regional atmospheric MC2 （Canadian Mesoscale Compressible Community） model that is one-way coupled to the Xinanjiang hydrological model. The system was tested for the July 4 to 15, 2005 severe flood event in real-time over the basin. The MC2 precipitation is first evaluated using observations from rain gauges over the Wangjiaba sub-region. The Xinanjiang model flood forecast is then validated with the observed hydrograph at the Wangjiaba Station. MC2 performs reasonably well in predicting severe precipitation with the forecast lead time up to 96-h. The flood forecast using MC2 precipitation shows a good result of flood timing and peak discharges at the Wangjiaba Station. The encouraging result obtained in this study demonstrates the potential of using mesoscale model precipitation for real-time flood forecast, which provides a longer flood lead time compared to many traditional methods.