Executive Summary : | India, a rapidly urbanizing country, faces risks such as heavy rainfall and flooding due to global warming-induced increases in intensity, duration, and frequency. Urban flood risk management and infrastructure design are directly influenced by water management practices and changes in land infiltration properties at the catchment scale. This study proposes a DandA analysis on observed changes in urban flood response, considering both climate and catchment scale changes. The analysis will involve analyzing changes in sub-daily extreme rainfall characteristics, delineating the role of urban water management practices on urban flooding risk, and exploring the opportunities and challenges of low impact developments (LIDs) in reducing urban runoff. LIDs, characterized by smaller-scale stormwater treatment devices, are characterized by bioretention systems, green roofs, and bioswales located near the source of runoff. To achieve these goals, the study will use long-term observed datasets of sub-daily rainfall at urban catchment scale, climate and hydraulic/hydrologic model simulations, and a statistical spatio-temporal disaggregation framework. Simulations of impact models, such as hydrologic and hydraulic models, will be employed, calibrated using short-term observed runoff data. The study will be conducted on Ahmedabad city as a case study, bringing together existing expertise at IIT Bombay on detection and attribution of climate change with respect to extreme rainfall and climate change mitigation in terms of stormwater management. |