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.
J Environ Manage. 2024 Aug;366:121829. doi: 10.1016/j.jenvman.2024.121829. Epub 2024 Jul 16.
Rain barrels/cisterns are a type of green infrastructure (GI) practice that can help restore urban hydrology. Roof runoff captured and stored by rain barrels/cisterns can serve as a valuable resource for landscape irrigation, which would reduce municipal water usage and decrease runoff that other stormwater infrastructures need to treat. The expected benefits of rainwater harvesting and reuse with rain barrels/cisterns are comprehensive but neither systematically investigated nor well documented. A comprehensive tool is needed to help stakeholders develop efficient strategies to harvest rainwater for landscape irrigation with rain barrels/cisterns. This study further improved the Soil and Water Assessment Tool (SWAT) in simulating urban drainage networks by coupling the Storm Water Management Model (SWMM)'s closed pipe drainage network (CPDN) simulation methods with the SWAT model that was previously improved for simulating the impacts of rainwater harvesting for landscape irrigation with rain barrels/cisterns. The newly improved SWAT or SWAT-CPDN was applied to simulate the urban hydrology of the Brentwood watershed (Austin, TX) and evaluate the long-term effects of rainwater harvesting for landscape irrigation with rain barrels/cisterns at the field and watershed scales. The results indicated that the SWAT-CPDN could improve the prediction accuracy of urban hydrology with good performance in simulating discharges (15 min, daily, and monthly), evapotranspiration (monthly), and leaf area index (monthly). The impacts of different scenarios of rainwater harvesting and reuse strategies (rain barrel/cistern sizes, percentages of suitable areas with rain barrels/cisterns implemented, auto landscape irrigation rates, and landscape irrigation starting times) on each indicator (runoff depth, discharge volume, peak runoff, peak discharge, combined sewer overflow-CSO, freshwater demand, and plant growth) at the field or watershed scale varied, providing insights for the long-term multi-functional impacts (stormwater management and rainwater harvesting/reuse) of rainwater harvesting for landscape irrigation with rain barrels/cisterns. The varied rankings of scenarios found for achieving each goal at the field or watershed scale indicated that tradeoffs in rainwater harvesting and reuse strategies exist for various goals, and the strategies should be evaluated individually for different goals to optimize the strategies. Efficient rainwater harvesting and reuse strategies at the field or watershed scale can be created by stakeholders with the assist of the SWAT-CPDN to reduce runoff depth, discharge volume, peak runoff, peak discharge, CSO, and freshwater demand, as well as improve plant growth.
雨水桶/蓄水池是一种绿色基础设施 (GI) 实践，可以帮助恢复城市水文学。雨水桶/蓄水池收集和储存的屋顶径流可以作为景观灌溉的宝贵资源，这将减少市政用水，并减少其他雨水基础设施需要处理的径流。雨水收集和再利用的预期好处是全面的，但既没有系统地调查，也没有很好地记录。需要一种全面的工具来帮助利益相关者制定有效的策略，以便利用雨水桶/蓄水池收集雨水进行景观灌溉。本研究通过将 Storm Water Management Model (SWMM) 的封闭管道排水网络 (CPDN) 模拟方法与先前改进的用于模拟雨水桶/蓄水池收集雨水进行景观灌溉对城市排水网络的影响的 SWAT 模型相结合，进一步改进了用于模拟城市排水网络的 Soil and Water Assessment Tool (SWAT)。新改进的 SWAT 或 SWAT-CPDN 用于模拟布伦特伍德流域（奥斯汀，德克萨斯州）的城市水文学，并在流域和流域尺度上评估利用雨水桶/蓄水池收集雨水进行景观灌溉的长期效果。结果表明，SWAT-CPDN 可以提高城市水文学的预测精度，在模拟排放（15 分钟、每日和每月）、蒸散（每月）和叶面积指数（每月）方面表现良好。不同雨水收集和再利用策略（雨水桶/蓄水池的大小、实施雨水桶/蓄水池的适宜区域的百分比、自动景观灌溉率和景观灌溉开始时间）对每个指标（径流深度、排放体积、峰值径流、峰值排放、合流制污水溢流-CSO、淡水需求和植物生长）的影响在流域或流域尺度上各不相同，为雨水桶/蓄水池收集雨水进行景观灌溉的长期多功能影响（雨水管理和雨水收集/再利用）提供了见解。在流域或流域尺度上实现每个目标的情景的不同排名表明，雨水收集和再利用策略之间存在权衡，对于不同的目标，应单独评估这些策略，以优化这些策略。利益相关者可以借助 SWAT-CPDN 创建流域或流域尺度的高效雨水收集和再利用策略，以减少径流深度、排放体积、峰值径流、峰值排放、CSO 和淡水需求，并改善植物生长。
