基于两种建模方式的嵌套式城市雨洪模型研究与应用

Research and application of nested urban rainstorm modeling based on two modeling approaches

全球气候变化和快速城镇化打破了城市水循环平衡,造成近些年来我国城市暴雨洪涝事件频繁发生。城市暴雨洪涝(雨洪)模型是应对城市洪涝事件的重要技术保障。然而,对于城市暴雨洪涝模拟,模拟精度和计算效率往往是一对矛盾体。本文总结了目前两种应用比较广泛的建模方式,即基于部分物理机制的水文单向驱动水动力模拟方式和基于完整物理机制的全过程双向耦合模拟方式。在此基础上,为了提高防汛应急处置工作的前瞻性和准确性,本文提出基于上述两种建模方式的嵌套式模拟方法。针对昆明主城区及其局部汇水区的模拟应用研究表明,嵌套式模拟方法在一定程度上缓解了城市雨洪模型在“整体”和“局部”、“精度”和“效率”之间的矛盾,具有较好的实用价值。

Global climate change and rapid urbanization have disrupted the balance of urban water cycle,leading to frequent occurrences of flood events in China’s cities in recent years.The urban pluvial flood model is an important technique for responding to urban flood events.However,for urban rainstorm and flood simulations,simulation accuracy and computational efficiency are often a trade-off.This paper summarizes the two widely used modeling approaches:the hydrological one-way driving hydrodynamic simulation method based on partial physical mechanisms and the full-process two-way coupling simulation method based on complete physical mechanisms.Based on this,in order to improve the foresight and accuracy of flood control and emergency response work,this paper proposes a nested simulation method based on the above two modeling approaches.Simulation applications for Kunming’s main urban area and its local watershed area show that the nested simulation method can to some extent alleviate the contradiction between“overall”and“local”,“accuracy”and“efficiency”in urban pluvial flood models and has good practical value.