Department of Civil Engineering, Bangladesh University of Engineering and Technology, Dhaka, Bangladesh; Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, NC, USA.
Department of Civil Engineering, Bangladesh University of Engineering and Technology, Dhaka, Bangladesh; Department of Civil, Construction, and Environmental Engineering, North Carolina State University, Raleigh, NC, USA.
J Environ Manage. 2021 Jul 1;289:112507. doi: 10.1016/j.jenvman.2021.112507. Epub 2021 Apr 8.
This study proposes a community rainwater harvesting (RWH) system as an alternative water supply solution for Paikgacha, a water-scarce coastal urban area in Bangladesh. Although individual household-based RWH systems have been implemented in many areas in Bangladesh, to date, no study has been conducted designing a community RWH system and assessing its reliability and financial feasibility. This study employs historical observed and available climate model predicted future rainfall data into stormwater management model (SWMM) for rainfall-runoff simulation of the community RWH, and compares SWMM's performance with rational formula based estimation. We then calculate volumetric and time reliability of the proposed system and assess its financial viability. We observe good agreement in reliability curves generated by SWMM and rational formula-based model. Under the historical rainfall scenario, our proposed community RWH shows up to 99% reliability for 100 L per day household demand, given that proper community size and storage tank size are chosen. Predicted rainfall pattern of 2041-2070 period shows similar reliability-tank size relation to that of historical observed rainfall; however, predicted high precipitation intensity during 2021-2040 and 2071-2100 seem to assist the system in attaining higher reliability. Cost-benefit analysis indicates the financial viability of the proposed system. Finally, we develop a nomograph incorporating interactive factors of RWH, which would ease decision making by the policymakers regarding the implementation of community RWH.
本研究提出了一种社区雨水收集（RWH）系统，作为孟加拉国缺水沿海城市 Paikgacha 的替代供水解决方案。尽管在孟加拉国的许多地区已经实施了个体家庭为基础的 RWH 系统，但迄今为止，尚未有研究设计社区 RWH 系统并评估其可靠性和财务可行性。本研究将历史观测和现有气候模型预测的未来降雨数据应用于雨水管理模型（SWMM），以模拟社区 RWH 的降雨径流，并将 SWMM 的性能与基于合理公式的估算进行比较。然后，我们计算了所提出系统的体积和时间可靠性，并评估了其财务可行性。我们观察到 SWMM 和基于合理公式的模型生成的可靠性曲线之间存在良好的一致性。在历史降雨情景下，我们提出的社区 RWH 对于每天 100 升的家庭需求，只要选择适当的社区规模和储水罐规模，可靠性高达 99%。2041-2070 年预测的降雨模式与历史观测的降雨模式具有相似的可靠性-储水罐尺寸关系；然而，预测的 2021-2040 年和 2071-2100 年期间高降水强度似乎有助于提高系统的可靠性。成本效益分析表明了所提出系统的财务可行性。最后，我们开发了一个包含 RWH 交互因素的诺谟图，这将为决策者在实施社区 RWH 方面的决策提供便利。
