绿色屋顶雨水滞留能力变化过程研究

Green Roofs, as one type of the advantageous practices of the Low Impact Development and Sponge City strategies，are now more and more widely used in urban areas. It’s important to understand the changes in stromwater retention capacity of green roofs (SRCGR) for their hydrologic design, modeling, and performance evaluation. Studies about the depletion (rainfall—runoff) process of SRCGR are active, while there are few studies investigating the recovery (evapotranspiration) process. In this study, both of the depletion and recovery processes of SRCGR will be comprehensively analyzed on the basis of continuous on-site observation of the meteorological and hydrological processes (rainfall, runoff and moisture contents) of 9 different green roofs. This study intends to explore the cycle (depletion & recovery) mechanisms of SRCGR and investigate the impacts of seasons, rainfall, growing media and vegetation conditions on the change of SRCGR. Based on the observations and analyses, a green roof retention capacity model which can reflect the impacts of seasons, rainfall, growing media and vegetation conditions on the change of SRCGR will be developed to simulate the depletion & recovery processes of SRCGR. And this model will be coupling embedded into the SWMM to improve the hydrological simulation of green roofs using SWMM. The results could be helpful to the hydrologic design, modeling, and performance evaluation of green roofs, and also provide reference for the implementation of the Sponge City strategies in China.

绿色屋顶作为海绵城市建设和低影响开发模式的优势措施之一，其雨水滞留效益受到越来越广泛的关注。掌握绿色屋顶雨水滞留能力的变化规律是合理设计绿色屋顶和准确评估绿色屋顶径流调控效益的重要基础。以往关于绿色屋顶雨水滞留能力的研究主要集中在消耗过程（降雨—径流过程），而对其恢复过程（蒸散发过程）的研究相对比较薄弱。本项目拟对9个不同类型绿色屋顶气象和水文过程进行连续监测，系统研究绿色屋顶雨水滞留能力的消耗和恢复过程，探索绿色屋顶雨水滞留能力的循环变化规律及其关键影响因素，重点揭示季节、降雨、生长基质及植被对绿色屋顶雨水滞留能力消耗和恢复过程的影响。在此基础上构建绿色屋顶雨水滞留能力消耗和恢复过程模型；将该模型与SWMM耦合，改进SWMM模拟绿色屋顶水文过程的精度。研究结果对绿色屋顶的水文过程模拟、水文设计和径流调控效益评估具有重要科学意义，并可为海绵城市建设提供理论支撑。

绿色屋顶作为城市生态修复的重要措施之一，其雨水滞留效益受到越来越广泛的关注。掌握绿色屋顶雨水滞留能力的变化规律是合理设计绿色屋顶和准确评估绿色屋顶径流调控效益的重要基础。本项目在北京建设15个不同基质类型与厚度、不同植被类型的实验绿色屋顶，通过三年连续动态监测、室内分析与水文模拟，在以下6方面取得重要进展：（1）揭示了绿色屋顶雨水滞留能力循环变化规律；（2）明确关键因素（基质类型与厚度、植被类型、气候条件）对绿色屋顶雨水滞留能力循环变化过程影响；（3）研发绿色屋顶雨水滞留能力消耗和恢复过程模型；（4）基于实验、Hydrus-1D、和SWMM模拟定量评估不同基质和植被条件下绿色屋顶径流调控效益；（5）通过实验监测解答绿色屋顶径流污染源汇问题；（6）初步监测评估绿色屋顶景观效益。项目执行3年来，较圆满完成各项计划任务和考核目标：（1）发表论文12篇（其中7篇SCI，2篇EI），共同主编相关教材1部，参编教材和专著各1部；（2）积累绿色屋顶的降雨（95场）、径流、雨水滞留能力、径流调控效益数据集1套；（3）培养博士毕业生1名，硕士毕业生4名；（4）对研究成果进行了广泛的学术交流，参加国际学术会议并做口头报告4次，参加国内会议4次。研究结果对绿色屋顶的水文过程模拟、水文设计和径流调控效益评估具有重要科学意义，并可为海绵城市提供理论支撑。