水资源容调蓄能力对快速城市化的响应及其敏感性研究

The rapid urbanization dramatically changes the underlying surface and the river network structure in recent years. It leads to constantly decreasing of water storage and regulation capacity, and causes a serious of problems, such as growing floods disaster, which has become a serious threat to the regional sustainable development. The project intends to take the Qinhuai River basin of the Yangtze River Delta as a typical area to carry out the response and sensitivity analysis of water storage and regulation capacity to the rapid urbanization based on the combined GIS-spatial-analysis, statistic and model technique. The aim of this study is to reveal the response mechanism of the storage and regulation capacity of the catchment/river to the underlying surface and river network structure during the rapid urbanization process; to quantificationally analyze the threshold and the temporal-spatial regularity of the capacity change; to clarify the temporal, spatial, and model sensitivity of the storage and regulation capacity; and finally propose countermeasures for the restore and protection of the catchment/river storage and regulation capacity. This study discuss the effects of the underlying surface and river network change on water storage and regulation capacity. The results can not only promote the development of hydrology research under changing environment, but also provide basis for decision making in urban flood prevention and control.

近年来城市化快速发展使区域下垫面及河流水系结构发生剧烈改变，致使流域与河道对水资源的容蓄及调蓄能力不断降低，由此引发的洪涝灾害加剧等问题严重威胁着区域可持续发展。本项目拟以长江三角洲的秦淮河流域为典型区，采用GIS空间分析、数理统计分析与耦合的数字模拟计算相结合的方法，开展水资源容调蓄能力对快速城市化发展的响应及其敏感性研究，旨在揭示剧烈城市化过程中研究区流域及河道容调蓄能力对下垫面及河网水系变化的响应机理、方式及程度，定量分析容调蓄能力的时空分异规律与变化阈值，阐明容调蓄能力对城市化进程响应的敏感性，最后基于敏感性分析提出流域水资源容调蓄能力恢复的对策。本研究探讨下垫面与河流水系变化对流域与河道水资源容调蓄能力的影响，以便丰富和发展变化环境下的水文研究，同时为城市防洪决策提供参考依据。

本研究以高度发达的长三角典型地区为例，综合运用RS和GIS技术，探究典型流域快速城市化进程中水系衰减和水位上涨等引起的流域容调蓄能力降低等严重的水安全问题，以及河流地貌学、水文地理学、景观生态学和空间统计学等多学科分析方法，遵循“河网水系格局演化→河网水位变化→流域容调蓄能力变化→应对措施”的主线，揭示了变化环境下河网水系格局演化和连通变化的特征与规律，剖析了水系演变与水位变化对河网调蓄的影响机制，研究时段内秦淮河流域总体调蓄能力呈下降趋势，下降幅度达到13.45%，由1980s的129.05*106m3到2010s的108.08*106m3，河网调蓄能力在城市化进程中最为稳定，相对下降幅度最小，对流域总体调蓄能力贡献最大。湖泊调蓄能力对城市化进程最为敏感，研究时段内有大幅增加70.75%。流域季节性调蓄与生态调蓄能力都有所降低，其中生态调蓄的下降幅度与数量都相对较大。贡献率最大的调蓄模块为河道调蓄能力。