Impacts of Urbanization on Watershed Water Balances Across the Conterminous United States
Impacts of Urbanization on Watershed Water Balances Across the Conterminous United States
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DOI：
10.1029/2019wr026574
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发表时间：
2020-06
影响因子：
5.4
通讯作者：
Cheng Li;G. Sun;P. Caldwell;E. Cohen;Yuan Fang;Yindan Zhang;L. Oudin;G. Sanchez;R. Meentemeyer
中科院分区：
文献类型：
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作者：
Cheng Li;G. Sun;P. Caldwell;E. Cohen;Yuan Fang;Yindan Zhang;L. Oudin;G. Sanchez;R. Meentemeyer
城市化通过从根本上改变流域降水、产水量和蒸散量之间的平衡，影响流域生态系统功能和服务。未来水文影响的准确量化对于国家城市规划和流域管理决策至关重要。我们假设，“水文城市化的影响是不平等的”作为一个结果，在气候和土地利用/土地覆盖变化（LULCC）的大空间变异性。验证并应用每月水平衡模型来量化美国本土（CONUS）81，900个12位水文单位代码（HUC）流域对2000年、2010年、2050年和2100年历史和预测LULC的水文响应。逐步回归和地理加权回归模型被用来确定关键因素控制的空间变化的水文影响整个美国大陆。虽然在国家层面上，未来城市化对产水量平均变化（ΔQ）的模拟影响很小，但到2050年和2100年，分别有1，046个和3，747个流域发生了显著变化（ΔQ > 50 mm/年）。水文响应在空间上各不相同，在美国东部更为明显。总体而言，城市化对产水量的影响受到当地气候，以前的LULC特征，以及土地利用和不透水面的变化幅度的影响。不透水面的持续增加，特别是在以前的城市化流域，和背景降水的贡献最大的未来ΔQ通过增加直接径流和减少ET。有效的国家级流域综合管理战略必须考虑当地的气候和土地利用/土地利用变化条件，以最大限度地减少城市化对水文的负面影响。
Urbanization impacts ecosystem functions and services by fundamentally altering the balances between precipitation, water yield (Q), and evapotranspiration (ET) in watersheds. Accurate quantification of future hydrologic impacts is essential for national urban planning and watershed management decision making. We hypothesize that “hydrologic impacts of urbanization are not created equal” as a result of the large spatial variability in climate and land use/land cover change (LULCC). A monthly water balance model was validated and applied to quantify the hydrologic responses of 81,900 12‐digit Hydrologic Unit Code (HUC) watersheds to historical and projected LULC in 2000, 2010, 2050, and 2100 in the conterminous United States (CONUS). Stepwise regression and Geographically Weighted Regression models were used to identify key factors controlling the spatially varied hydrologic impacts across CONUS. Although the simulated impact of future urbanization on mean change in water yield (ΔQ) was small at the national level, significant changes (ΔQ > 50 mm/year) were found in 1,046 and 3,747 watersheds by 2050 and 2100, respectively. Hydrologic responses varied spatially and were more pronounced in the eastern United States. Overall, the impacts of urbanization on water yield were influenced by local climate, previous LULC characteristics, and the magnitude of changes in land use and impervious surfaces. The continued increase in impervious surface, especially in previously urbanized watersheds, and background precipitation contributed most to future ΔQ through both increase in direct runoff and reduction in ET. Effective national‐scale integrated watershed management strategies must consider local climatic and LULC conditions to minimize negative hydrologic impacts of urbanization.