Bose Tushar, Kalbar Pradip P, Mondal Arpita
Faculty of Technology, CEPT University, Navrangpura, Ahmedabad, 380009, India; Interdisciplinary Program in Climate Studies, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.
Interdisciplinary Program in Climate Studies, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India; Centre for Urban Science and Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.
J Environ Manage. 2024 Aug;365:121500. doi: 10.1016/j.jenvman.2024.121500. Epub 2024 Jun 24.
Urban flooding poses a significant challenge to the rapidly growing Indian cities. Low-impact development strategies such as green roofs have shown the potential to reduce urban flooding. However, their performance assessment significantly varies across different studies. Therefore, the study's primary objective is to evaluate green roofs in the Indian context. For this evaluation, the green roofs are assessed based on building-level implementation scenarios for a high-density urban area in India for 25%,50%, and 75% application rates and different rainfall intensities (2,3 and 4-h duration and 2,5,10 and 25-year frequencies). Secondly, to probe the variations in the green roof performance across studies, uncertainty contributions to the runoff reduction from different parameters are quantified. The results show that green roofs can reduce up to 62% of flood volume and 24% of runoff. However, they are reasonably effective only beyond 25% application rates. Further, rainfall intensity contributes the most to the uncertainty of runoff reduction from green roofs. This uncertainty assessment implies that localized evaluation of green roofs depending on local rainfall conditions is required for city-wide policy planning. The study has a significant contribution to building confidence in the ability of green roofs to reduce urban floods in the context of developing countries like India.
城市内涝给快速发展的印度城市带来了重大挑战。诸如绿色屋顶之类的低影响开发策略已显示出减少城市内涝的潜力。然而，它们的性能评估在不同研究中差异很大。因此，该研究的主要目标是在印度背景下评估绿色屋顶。为了进行这种评估，基于印度高密度城市地区25%、50%和75%的应用率以及不同降雨强度（2、3和4小时持续时间以及2、5、10和25年一遇频率）的建筑层面实施场景对绿色屋顶进行评估。其次，为了探究不同研究中绿色屋顶性能的差异，对不同参数对径流减少的不确定性贡献进行了量化。结果表明，绿色屋顶可减少高达62%的洪水量和24%的径流量。然而，它们只有在应用率超过25%时才具有合理的有效性。此外，降雨强度对绿色屋顶径流减少不确定性的贡献最大。这种不确定性评估意味着，在进行全市范围的政策规划时，需要根据当地降雨条件对绿色屋顶进行本地化评估。该研究对于在印度等发展中国家背景下增强人们对绿色屋顶减少城市内涝能力的信心具有重大贡献。
