基于城市复杂下垫面特征的分布式水文模型研究

Urbanization, at the same time of bringing chances of economic development, technical innovation and social progress, is often with ecological costs. The most two obvious negative effects of fast urbanization are more severe criticized due to increased risk of flooding and water scarcity. Stormwater management has the potential to reduce the risk and impact of flooding and deliver an additional water resource to augment potable supply. Distributed hydrological model has become an essential tool in stormwater management, which can provide the decision information by describing the storm runoff process in detail. According to the underlying surface characteristics, a distributed hydrological model adopting triangulated irregular network is developed and applied in Liangshui basin, Which locates in Beijing city. Based on the quantitative description of the underlying surface and the spatial distribution of the rivers and streets, the triangulated irregular network is generated. The processes of runoff generation is simulated using tanks as triangulated grids in vertical direction, which is adopted in the Physically-based Distributed Tank model (PDTank). Physically based equations are utilized to describe water movement along the grid network, i.e., the 2D Saint-Venant equation is used to simulate the overland flow process along the planar direction in the grid network, and the 1D Saint-Venant equation is used to simulate the street, sewer, and river flows. The finite volume method is used to solve these equations. By using the triangulated irregular network for spatial discretization, the model can not only represent the heterogeneity of underlying surface in a realistic and efficient manner, but also be suitable for the couple modeling of strom runoff processes. The aim of the research is to provide accurate and timely information for stormwater management, and prompt the development of urban hydrological models by studying the modeling method of complex underlying surface.

随着我国城市化的发展，洪涝灾害和水资源紧张的矛盾日益凸显。开展雨洪管理，合理利用雨洪资源，是解决这一问题的有效途径。开发分布式水文模型，系统模拟雨洪过程，将能为城市雨洪管理提供全面的信息支持。研究选择北京市马草河流域为研究对象，针对城市下垫面特点，构建基于不规则三角形网格的分布式水文模型。通过对下垫面特征的定量描述和河流、街道等汇流通道的空间叠加分析，生成反映城市下垫面产汇流特征的不规则三角形格网。在PDTANK模型的产流机制的基础上，分别采用一维和二维水动力学模型模拟城市区域的多种汇流形式。并采用有限体积法建立了求解方案。研究通过采用不规则三角形的离散形式，充分利用下垫面的多尺度信息，更好的反映洪水演进过程的边界特征，提高城市雨洪过程模拟的效率和精度。与此同时，深入探讨城市复杂下垫面条件下的分布式水文模型建模和求解方法，将有力促进城市水文模型的发展。

城市雨洪管理是城市可持续发展的重要的重要保障。在过去三十年，我国经历了快速的城市化过程。由于城市水文气象条件的改变，洪涝灾害频发已经成为我国城市水安全的重要威胁。因此，海绵城市建设成为我国城市水安全的重要战略。其中，可靠的水文模型是海绵城市建设重要的技术支撑。.研究以北京市凉水河流域(马草河的上级流域，含马草河流域)为典型，在对SWMM模型进行深入研究的基础上，开发适用于城市复杂下垫面特征的分布式水文模型。.首先，研究对SWMM模型在北京市的适用性进行了研究。在北京市主城区凉水河流域、通惠河流域、清河流域及坝河流域建立了SWMM模型，并采用实测流量数据对模型参数进行了率定及验证。并以凉水河大红门排水区为研究对象，采用SWMM模型分别对城市化前、后两种情景进行模拟，并通过设置不同频率降水情景，定量分析快速城市化对流域产汇流的影响。其次，采用Morris筛选法、GLUE方法对SWMM模型的主要参数的敏感性以及模型结果的不确定性进行研究，为模型改进奠定基础。针对城市防洪的需要，开发了基于多目标的城市洪水预报模型不确定性分析方法。通过在凉水河流域的应用发现，在包含相同的观测洪水的同时，多目标分析方法的不确定范围大幅降低，尤其是洪峰流域，中值预报成果也显著提高。最后，通过将不规则网格填洼模型和SWMM模型进行耦合，构建了适合城市复杂下垫面的分布式水文模型。通过在天堂河流域的应用以及与MIKE11/MIKE21模型的精度对比，淹没水深与相关水动力学研究结果较为一致，在模型精度相似的同时，实现了更快的运行时间和模型效率。.项目开发的北京市凉水河、通惠河流域城市雨洪模拟模型已经在北京市防汛抗旱指挥部和北京市水文总站投入实际运行，为首都水安全提供了支撑与保障；与此同时，项目在城市雨洪模拟模型的不确定性分析、城市洪涝模拟模型的开发上取得创新。共发表论文11篇，其中SCI，EI论文3篇。且有5篇SCI论文在外审阶段。