基于高精度DEM的城市道路积水淹没计算方法研究

针对河南省郑州市城区道路微尺度场景的暴雨内涝积水计算问题,以车载LiDAR技术建立的积水路段高精度格网DEM为基础,按照有源淹没方式,采用种子蔓延法计算积水淹没范围;通过构建郑州市暴雨洪水模型获取暴雨时积水点溢流水量,运用二分法实现淹没水位与溢流水量间的快速逼近求解。以郑州市某积水路段进行实例应用,对比分析计算结果与电子水尺实测水深数据可知,Nash-Sutcliff确定性系数为0.94,RMSE为0.05,相对误差为10.3%,表明淹没计算结果具有较高精度,模拟淹没过程符合该积水区实际淹没过程,研究方法适用于城市街道区域的暴雨积水淹没范围和水深计算。

High precision DEM-based study on method for calculation of urban road waterlogging and submergence

Aiming at the calculation of the waterlogging caused by rainstorm in the micro-scale scene of the urban road in Zhengzhou, the waterlogging submerged range is calculated with the seed spread algorithm according to the mode of source flood submergence on the basis of establishing the high precision grid DEM with the technique of vehicle LiDAR, and then the quick approaching solving between the submerged level and the amount of overflow is realized with the dichotomy method by obtaining the amount of overflow at the point of waterlogging during rainstorm through constructing the rainstorm-flood model of Zhengzhou. By taking a waterlogging road section in Zhengzhou as the application case, it is known from the comparison made between the results of the analysis and calculation and the data of water depth measured by electronic watergauge that the Nash-Sutcliff determination coefficient is 0. 94, RMSE is 0. 05 and the relative error is 10. 3%, which indicates that the calculated result of the submergence has higher precision and the simulated submergence process of the waterlogging area is coincided with that of the actual situation.The method is suitable for the calculations of both the submerged range and water depth of rainstorm waterlogging in the urban street area concerned.