降雨空间分辨率对城市内涝模拟敏感性研究

为研究降雨空间分辨率对城市内涝模拟的影响规律以及一、二维耦合的城市雨洪模型的敏感性降雨空间分辨率，本研究选取西安市小寨片区为研究区，以西安市气象局提供的3场降雨为基础，采用空间插值算法获取5种降雨（0.2、0.5、1.0、2.0和4.0 km）空间分辨率，引入洛伦兹曲线、基尼系数判断不同降雨空间分辨率的不均匀程度，驱动一、二维耦合的城市雨洪模型进行模拟分析。结果表明，3场降雨0.5 km降雨空间分辨率对应的基尼系数分别为0.163、0.201、0.165，评价结果均为均匀分布。随着降雨空间分辨率的降低，基尼系数逐渐减小，峰值积水面积相对误差、内涝积水水量相对变化范围、内涝淹没水深相对变化范围均逐渐增大。对于这3个水力要素评价指标，降雨空间分辨率为0.5 km对应的模拟误差最小，且该降雨空间分辨率为敏感性降雨空间分辨率。

Sensitivity of rainfall data spatial resolution to urban inundation simulation

To study the impact of rainfall spatial resolution on the simulation of urban inundation and the sensitivity of a one-two-dimensional coupled urban inundation model, this research selected the Xiaozhai area of Xi’an City as the study area. Based on three rainfall datasets provided by the Xi’an Meteorological Bureau, the spatial interpolation algorithm of inverse distance weighting was used to obtain five rainfall spatial resolutions: 0.2, 0.5, 1.0, 2.0, and 4.0 km. The Lorenz curve and Gini coefficient were introduced to assess the uniformity of different rainfall spatial resolutions, and they were used to drive the one-two-dimensional coupled urban inundation model for simulation analysis. The results indicate that for the three rainfall events, the Gini coefficients corresponding to the 0.5 km rainfall spatial resolution are 0.163, 0.201, and 0.165, indicating uniformly distributed evaluations. As the rainfall spatial resolution decreases, the Gini coefficient gradually decreases, while the relative errors of peak inundation area, relative changes in inundation volume, and relative changes in inundation depth all gradually increase. In terms of these three hydraulic evaluation indicators, the simulation error is the smallest for the rainfall spatial resolution of 0.5 km, and this resolution is identified as the sensitive rainfall spatial resolution.