Department of Environmental and Sustainable Engineering, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA.
Department of Environmental and Sustainable Engineering, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY 12222, USA.
Sci Total Environ. 2021 Dec 1;798:149336. doi: 10.1016/j.scitotenv.2021.149336. Epub 2021 Jul 30.
Rain barrels/cisterns, a popular type of low impact development (LID) practice, can restore urban hydrological processes and decrease municipal water use by harvesting roof runoff for later use, such as landscape irrigation. However, tools to assist decision makers in creating efficient rainwater harvesting and reuse strategies are limited. This study improved the Soil and Water Assessment Tool (SWAT) in simulating the subdaily hydrological impacts of rainwater harvesting for landscape irrigation with rain barrels/cisterns, including the simulation of rainwater harvesting with rain barrels/cisterns, rainwater reuse for auto landscape irrigation, evapotranspiration, initial abstraction, impervious area, soil profile, and lawn management operation. The improved SWAT was applied in the urbanized Brentwood watershed (Austin, TX) to evaluate its applicability and investigate the impacts of rainwater harvesting and reuse strategies on the reductions and reduction efficiencies (reductions per volume of rain barrels/cisterns implemented) of field scale runoff (peak and depth) and watershed scale streamflow (peak and volume) for two storm events. Scenarios explored included different sizes of rain barrels/cisterns, percentages of rooftop areas with rain barrels/cisterns implemented, auto landscape irrigation rates, and landscape irrigation starting times. The performance of rainwater harvesting and reuse strategies, which is determined by features of fields, watersheds, and storm events, varied for different reduction goals (streamflow or runoff, and peak or depth/volume). For instance, the scenario with rain barrel/cistern sizes of 7.5 mm (design runoff depth from treated roof area) and the scenario with 10% of suitable area implemented with rain barrels/cisterns provided the highest peak streamflow reduction efficiency and total streamflow volume reduction efficiency at the watershed scale, respectively for the smaller storm event. To achieve sustainable urban stormwater management, the improved SWAT model has enhanced capability to help stakeholders create efficient rainwater harvesting and reuse strategies to reduce field scale runoff and watershed scale streamflow.
雨水桶/蓄水池是一种流行的低影响开发 (LID) 实践，可以通过收集屋顶径流用于后期景观灌溉等用途来恢复城市水文过程并减少市政用水量。然而，用于协助决策者制定高效雨水收集和再利用策略的工具有限。本研究改进了土壤和水评估工具 (SWAT)，以模拟雨水桶/蓄水池用于景观灌溉的亚日尺度雨水收集对水文的影响，包括雨水桶/蓄水池的雨水收集模拟、雨水自动景观灌溉再利用、蒸散、初始提取、不透水面积、土壤剖面和草坪管理作业。改进后的 SWAT 应用于布伦特伍德流域（奥斯汀，TX）进行城市化，以评估其适用性，并研究雨水收集和再利用策略对减少和减少效率（每实施雨水桶/蓄水池体积的减少）的影响田间尺度径流（峰值和深度）和流域尺度溪流（峰值和体积）的两个风暴事件。探讨的情景包括不同大小的雨水桶/蓄水池、实施雨水桶/蓄水池的屋顶面积百分比、自动景观灌溉率和景观灌溉开始时间。雨水收集和再利用策略的性能取决于流域和风暴事件的特征，因不同的减少目标（流量或径流、峰值或深度/体积）而异。例如，对于较小的风暴事件，雨水桶/蓄水池尺寸为 7.5 mm（处理后屋顶面积的设计径流深度）的情景和 10%的合适区域实施雨水桶/蓄水池的情景分别提供了流域尺度上最高的峰值流量减少效率和总流量减少效率。为了实现可持续的城市雨水管理，改进后的 SWAT 模型具有增强的能力，可以帮助利益相关者制定高效的雨水收集和再利用策略，以减少田间尺度的径流和流域尺度的流量。
