Quantifying the effects of urbanization on floods in a changing environment to promote water security — A case study of two adjacent basins in Texas
Quantifying the effects of urbanization on floods in a changing environment to promote water security — A case study of two adjacent basins in Texas
复制标题
DOI：
10.1016/j.jhydrol.2020.125154
复制
发表时间：
2020-10
影响因子：
6.4
通讯作者：
M. Shao;Gang Zhao;S. Kao;L. Cuo;C. Rankin;Huilin Gao
中科院分区：
文献类型：
--
作者：
M. Shao;Gang Zhao;S. Kao;L. Cuo;C. Rankin;Huilin Gao
城市化和全球气候变化导致的洪灾事件增多，对水安全构成了巨大威胁。为了系统地评估城市化对洪水的影响，我们对德克萨斯州中南部的两个相邻的河流流域--城市化速度较快的圣安东尼奥河流域(SARB)和土地覆盖变化较小的瓜达卢佩河流域(GRB)--采用了APARED集水方法。采用一个基于物理的分布式水文模型--嵌入多用途水库模块的分布式水文土壤植被模型(DHSVM-RES)模拟径流和水库蓄水。这些模拟是在不同的土地覆盖情景下进行的，包括新开发的连续土地覆盖系列(CLCS)。然后使用三种方法对配对流域进行整体分析：分析选定的洪水事件、检测每月洪水的变化点(CP)和测试长期洪水动态的弹性。结果表明：(1)城市化可以缩短滞后时间，将洪峰抬高3-30%；(2)当土地覆盖变化不大时，气候变化是月最大径流变化的主要驱动因素；(3)快速城市化可以放大径流变率，显著增加月最大径流量，从而改变CP的时间；(4)从CP前到CP后，SARB观测到的径流MMS平均增加了75.7%。这项全面的研究填补了我们目前对城市化对洪水的孤立影响的理解的空白，预计将支持未来对洪水的人为影响的探索。
The increased occurrence of flood events resulting from urbanization and global climate change is a great threat to water security. To systematically evaluate the impacts of urbanization on floods, we applied apaired catchmentsapproach to two adjacent river basins in south-central Texas — the San Antonio River Basin (SARB), with fast urbanization; and the Guadalupe River Basin (GRB), with little land cover change. A physics-based distributed hydrological model — the Distributed Hydrology Soil Vegetation Model, embedded with a multi-purpose reservoir module (DHSVM-Res) — was used to simulate streamflow and reservoir storage. The simulations were conducted under different land cover scenarios, including a newly developed continuous land cover series (CLCS). Holistic analyses were then conducted for the paired basins using three methods: analyzing the selected flood events, detecting change points (CP) of monthly floods, and testing the elasticity of long-term flood regimes. The results suggest that: (1) urbanization may reduce lag time and elevate flood peaks significantly by 3–30% in our study area; (2) when there is little land cover change, changing climate is the major driver of variations in the monthly maximum streamflow (MMS); (3) fast urbanization can amplify streamflow variability, increase MMS significantly, and thus alter the timing of CP; and (4) the mean MMS of observed streamflow in the SARB has increased by as much as 75.7% from the pre-CP to post-CP periods. This comprehensive study fills in a gap in our current understanding of the isolated impacts of urbanization on flooding and is expected to support future explorations of anthropogenic influences on floods.