【摘要】 闸坝工程的大量修建,严重影响了流域水文情势和水循环过程,天然状况下流域汇流单位线已无法适用.本文在传统Nash瞬时单位线将流域对洪水的调蓄视为n个线性串联水库出流的基础上,考虑闸坝工程对洪水过程推移和坦化的影响,通过添加与前n个水库不同的第n+1个虚拟水库,等效模拟闸坝工程对洪水过程的调蓄作用,提出了适用于闸坝影响下的流域汇流单位线,并应用于闸坝影响突出的淮河流域洪水预报.研究表明:相比传统Nash单位线,该方法能显著提高洪水预报精度,对洪峰流量和退水过程的模拟效果改进尤佳.本文所提出的方法发展了单位线理论,拓展了单位线适用范围,提高了闸坝工程影响下的洪水预报精度,为研究人类活动对流域水文水资源的影响提供了一种新方法.更多还原

【Abstract】 The construction of dams and sluices will directly influence the water cycle,which resulted in the inappropriate application of traditional Unit Hydrograph( UH) proposed based on the assumption of natural watersheds. In this paper,based on the theory of Nash Instantaneous Unit Hydrograph( Nash IUH),which regarded the attenuation of floods from watersheds as the outlet flow of n cascades of reservoirs,a new unit hydrograph was proposed which was suitable for dams and sluices influenced watersheds. This UH added an extra reservoir,i. e. the( n + 1) th reservoir which was different from the previous n reservoirs,at the cascades end to simulate the translation and attenuation impacts of these water projects. The new method was then applied to the flood forecasting in the Huai River Basin where large amount of water projects were built.The results indicated that compared with the Nash IUH,the proposed method can greatly improve the flood forecasting accuracy,especially for the peak discharge and flow recession. The method introduced in this paper not only develops the theory of UH,but also expands the application scope of UH. It can greatly enhance the accuracy of flood forecasting under the impacts of dams and sluices,which provides a new approach for investigation into the human impacts on hydrology and water resources.更多还原