SUITABILITY ASSESSMENT FOR PLUVIAL FLOOD MITIGATION IN DENSE URBAN AREAS, USING NATURE-BASED SOLUTIONS: A CASE OF DELHI

Over the past few years, pluvial floods have become a major concern for Indian cities. Factors that exacerbate the conditions include climate change, urbanisation, outdated stormwater infrastructure, decreasing capacity of natural wetlands, and natural stormwater sinks. India's metropolitan cities are at risk due to the current rate of urbanisation. The paper aims to develop a methodology that can be used to identify the areas at risk due to pluvial floods at a watershed scale and its mitigation through nature-based solutions (NBS) using geospatial analysis by considering the case of Delhi. Based on local flood data, the settlements at risk of pluvial floods were mapped using GIS, and the "Pluvial flood susceptibility map" has been developed to assess the risk of flooding, followed by selection of the most vulnerable local action area with the help of parameters like susceptibility (based on past pluvial flooding incidences) and urbanisation. Further, in the research, the "NBS suitability map" for the milli watershed (area of about 1000 to 10,000 ha) has been generated using the geospatial overlay technique of GIS. It can help identify potential areas within the study region at a sub-watershed level where nature-based solutions can be integrated, considering suitable and unsuitable conditions based on physical, environmental, and planning parameters.