城镇化低影响开发技术参数试验及数值模拟研究

China has entered a decisive stage of building a well-off society in an all-round way, and the degree of urbanization is one of the important symbols of a well-off society. The concept of low impact development conforms to the basic principles of the new national urbanization construction and the national strategic needs of "ecological priority and green development". Permeable paving, subsidence green space, biological detention facilities and ecologic riparian belt are the typical low impact development engineering facilities in the construction of "sponge city". Aiming to select the middle or small city in the Yangtze River Delta as the object, the prototype state physics models are built，which represent the above four types of low impact development engineering. The Infiltration law, water storage capacity, and reduction effect of rainwater runoff pollution in medium layer and surface vegetation of physics models are studied. The constitutive relation between technical parameters of low impact development projects is revealed. The hydrodynamic and water quality model is constructed applying to the four types engineering above. The optimal the structure and technical parameters for low impact development engineering are sought, which provide the effective and reliable quantitative basis for project planning and design.

我国已进入全面建成小康社会的决定性阶段，城镇化程度是小康社会的重要标志之一。低影响开发理念符合国家新型城镇化建设遵循的基本原则，以及“生态优先、绿色发展”国家战略需求。透水铺装、下沉式绿地、生物滞留设施及生态河岸带属于“海绵城市”建设中典型的低影响开发工程设施。本项目拟选择长江三角洲城市群中的中小型城市为对象，构造透水铺装、下沉式绿地、生物滞留设施及生态河岸带这四类低影响开发工程设施的原型态物理模型，探明各工程设施介质层及表层植被的入渗规律、蓄水能力及对雨水径流污染的削减效应，揭示低影响开发工程技术参数之间的本构关系，构建适用于上述四类工程设施的水动力-水质耦合模型，探寻低影响开发工程设施的优化结构及技术参数，为低影响开发工程规划设计提供有效可靠的定量依据及技术支撑。

探寻LID设施的优化结构和技术参数在改善城市生态环境中具有极其重要的价值。LID设施的关键参数值大多源于国外早期实验，难以满足当前海绵城市建设目标的有效性和可靠性。为探明各类工程设施系统整体的雨洪调蓄能力和径流污染的削减效应，需要构建数值耦合模型。本项目选取了不同类型和结构的LID设施，开展了一系列的水量、水质观测实验，分析了透水铺装、下沉式绿地、生物滞留设施和生态河岸带四类设施关键参数的取值区间和本构关系；构建了适用于各设施的水动力-水质耦合模型，并借助经过参数率定的模型评估了不同规模设施建设情景下的雨水径流调控及污染物削减效果。本项目的相关成果可以为LID设施的工程规划设计提供依据及技术支撑。