Water Balances along an Urban-to-Rural Gradient of Metropolitan Baltimore, 2001-2009
Water Balances along an Urban-to-Rural Gradient of Metropolitan Baltimore, 2001-2009
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DOI：
10.2113/gseegeosci.18.1.37
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发表时间：
2012-02-01
影响因子：
0.9
通讯作者：
Welty, Claire
中科院分区：
文献类型：
--
作者：
Bhaskar, Aditi S.;Welty, Claire
城市水平衡一般是未知的，但它们是必要的，以评估水的供应在一个城市化的世界，并了解城市化对水文循环的影响。我们评估了2001-2009年水资源年期间，马里兰州巴尔的摩大都市区65个流域水平衡的时空变化。每个水平衡项都是独立量化的，包括自然（降水，蒸散，径流）和管道（下水道渗透和流入[I&I]，草坪灌溉，供水管道泄漏）流域流入和流出。分析还比较了重力恢复和气候实验存储数据的变化，存储使用流域流入和流出之间的残差计算。我们发现，当只考虑自然水平衡条款，水平衡的剩余（流入减去流出）增加与城市化，主要是由于蒸散量的减少模拟的陆面模型全球陆地数据同化系统/诺亚。在丰水年，由于城市径流量的增加，城市和农村天然水平衡残差之间的差异缩小。城市地区自然水平衡中多余的水主要由I&I输出到废水收集管道;对于一些城市流域，这种多余的水大于测量的年流量。在巴尔的摩地区分析中，I&I还超过了草坪灌溉和供水管道泄漏的管道输入。管道流量对城市水平衡的净影响是流域输出量在300和465毫米/年之间，强调了工程用水和废水基础设施与自然水平衡组成部分之间相互作用的重要性。
Urban water balances are generally unknown, yet they are necessary for assessing water availability in an urbanizing world and for understanding the effects of urbanization on the hydrologic cycle. We assess the spatial and temporal variability of water balances of 65 watersheds in the Baltimore, MD, metropolitan area during Water Years 2001-2009. Each water balance term is quantified independently and includes both natural (precipitation, evapotranspiration, streamflow) and piped (sewer infiltration and inflow [I&I], lawn irrigation, water supply pipe leakage) watershed inflows and outflows. The analysis also compares Gravity Recovery and Climate Experiment storage data with changes in storage calculated using the residual between watershed inflows and outflows. We find that when considering only natural water balance terms, the water balance residual (inflows minus outflows) increases with urbanization, largely as a result of the decrease in evapotranspiration as modeled by the land surface model Global Land Data Assimilation System/Noah. During wet years, the difference between urban and rural natural water balance residuals narrows because of increased urban streamflow. Excess water of the natural water balance in urban areas is largely exported by I&I into wastewater collection pipes; for some urban watersheds this excess is greater than gauged annual streamflow. I&I also outweighs piped inputs from lawn irrigation and water supply pipe leakage in the Baltimore area analysis. The net effect of piped flows on the urban water balance is a watershed export ranging between 300 and 465 mm/yr, underscoring the importance of interactions between engineered water and wastewater infrastructure and natural water balance components.