城镇化对长江下游地区产汇流影响机制与洪涝防控研究

The changes in the land use pattern due to rapid urbanization in the lower reaches of Yangtze River have adversely resulted in a series of problems, including the frequent occurrence of extreme rainstorm and the intensification of flood disaster. In the light of given facts, we take Taihu Basin, for example, as a typical study area to compare the changes of land use in different periods to reveal the temporal and spatial characteristics of the increase of impervious area and the attenuation of the river system quantitatively. The influences of urbanization on hydrological factors are ascertained by using the long-term data of precipitation, runoff and water level. Based on the analysis of the variations of the storm flood extreme event frequencies, the characteristics of storm flood influenced by urbanization are revealed. By means of observing the storm flood processes in response to varying degrees of urbanization and spatial scales, the rules of “four-water” transformation and runoff characteristics are discussed through the comparison among different experimental areas. Assisted with the comprehensive simulation of storm flood and the river flood routing, we demonstrate the mechanism of runoff formulation affected by urbanization. Considering the scheduling of flood control projects, such as pumps and sluices, dynamic simulations of flood storage capacity are carried out based on the analysis before. We coordinate the relationship of flood among the scales of city, region and basin from the view of watershed and region. The countermeasures of flood prevention and control in the highly urbanized area of the lower reaches of the Yangtze River are explored in order to provide the theoretical basis and technical support for regional flood control and disaster alleviation and promote the sustainable development of the region.

针对我国长江下游地区，快速城镇化下流域下垫面变化导致极端暴雨频发、洪涝危害加剧问题，以太湖流域等为典型区，对比分析不同时期下垫面变化，定量揭示城镇化背景下不透水面积增加与河流水系衰减的时空特征；利用长时间序列流域降雨、水位与径流资料，探讨城镇化对水文要素的影响；基于城镇化下暴雨洪水极端事件的频率变化分析，揭示城镇化下暴雨洪水变化特征；采用不同城镇化水平、不同空间尺度的暴雨洪水过程观测实验，通过不同实验区对比观测分析，探求城镇化下四水转换与径流特征变化规律，并借助流域暴雨洪水综合模拟与河网演进模拟，揭示城镇化对流域产汇流影响机制。在此基础上，结合区域内圩垸与闸泵等防洪工程调度，开展城镇化地区洪涝调蓄能力动态模拟，从流域与区域层面来协调城市、区域与流域洪涝之间的关系，探寻城镇化地区洪涝防控的对策措施，为长江下游地区防洪减灾提供技术支撑，促进区域经济社会可持续发展。

本研究针对我国长江下游地区，快速城镇化下流域下垫面变化导致极端暴雨频发、洪涝危害加剧问题，以太湖流域等为典型区，对比分析不同时期下垫面变化，定量揭示了城镇化背景下不透水面积增加与河流水系衰减的时空特征；利用长时间序列流域降雨、水位与径流资料，探讨了城镇化对水文要素的影响；基于城镇化下暴雨洪水极端事件的频率变化分析，揭示了城镇化下暴雨洪水变化特征；采用不同城镇化水平、不同空间尺度的暴雨洪水过程观测实验，通过不同实验区对比观测分析，探求城镇化下四水转换与径流特征变化规律，并借助流域暴雨洪水综合模拟与河网演进模拟，揭示了城镇化对流域产汇流影响机制。在此基础上，结合区域内圩垸与闸泵等防洪工程调度，开展城镇化地区洪涝调蓄能力动态模拟，从流域与区域层面来协调城市、区域与流域洪涝之间的关系，探寻了城镇化地区洪涝防控的对策措施，为长江下游地区防洪减灾提供技术支撑，促进区域经济社会可持续发展。