Quantifying the effects of urbanization on floods in a changing environment to promote water security - A case study of two adjacent basins in Texas

JOURNAL OF HYDROLOGY

卷:589

Article

Shao, Manqing¹  Zhao, Gang¹  Kao, Shih-Chieh^2,3  Cuo, Lan^4,5  Rankin, Cheryl¹  Gao, Huilin¹ 

[1] Texas A&M Univ, Zachry Dept Civil & Environm Engn, College Stn, TX 77843 USA

[2] Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA

[3] Oak Ridge Natl Lab, Climate Change Sci Inst, POB 2008, Oak Ridge, TN 37831 USA

[4] Chinese Acad Sci, Ctr Excellence Tibetan Plateau Earth Sci, Inst Tibetan Plateau Res, Key Lab Tibetan Environm Changes & Land Surface P, Beijing 100101, Peoples R China

[5] Univ Chinese Acad Sci, Beijing 100101, Peoples R China

关键词: Urbanization;    Paired catchments;    Hydrological modeling;    Changing climate;    Land cover change;    Water security;   

DOI  :  10.1016/j.jhydrol.2020.125154

来源: Elsevier

【 摘 要 】

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 a paired catchments approach 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 lithe 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.

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