Leveraging Nature-Based Solutions for Urban Resilience and Climate Adaptation: Fid-Bau Portal

Leveraging Nature-Based Solutions for Urban Resilience and Climate Adaptation

Nair, Manish M. / Parween, Shama / Sinha, Rajan Chandra

In the last few decades, the escalation of pluvial flood occurrences has posed a significant concern for densely populated urban centres. This surge is attributed to amplified precipitation patterns driven by climate change, insufficient infiltration capacities due to land use and cover alterations, increased surface sealing, and inadequate stormwater infrastructure, all consequences of rapid urbanization. Over recent years, pluvial flood incidences have increased globally, particularly affecting Southeast Asian nations. Delhi, for instance, witnessed six urban floods between 2002 and 2016, indicative of the alarming pace of urbanization in the national capital, with 75.09% of its geographical area now classified as urban. According to the 2011 census, 97.5% of Delhi's populace resides in urban locales, with 60% of residents inhabiting unplanned settlements. These urban expansions, fuelled by migration, have encroached upon agricultural and green spaces, exacerbating the risk of pluvial floods. During the peak monsoon periods, numerous unplanned neighbourhoods and transport networks in Delhi are inundated, causing traffic disruptions and inconvenience for commuters. Addressing this challenge requires sustainable and resilient infrastructure solutions, prioritizing the implementation of nature-based approaches. This chapter proposes an integrated four-stage stormwater planning system employing Nature-Based Solutions (NBS) such as swales, rain gardens, permeable pavements, stormwater ponds, curb extensions, planters, and vegetative filter strips. The Soil Conservation Service Curve Number (SCS-CN) method was used to estimate runoff generated during the 10-year maximum rainfall event in Aug 2020. The runoff left after initial abstraction and the quantity conveyed through stormwater pipelines was estimated to be 29% of the runoff generated per hour. Through a four-stage planning approach, NBS features were strategically integrated within the study area, resulting in an 85.67% reduction in excess runoff, predominantly through stormwater collection (80.48%) and infiltration (5.19%). This study provides valuable insights for stakeholders in devising strategies for the selection, placement, and execution of future nature-based planning strategies, aligning with the Sustainable Development Goals (SDGs) 11, 6, and 13, thus contributing to the 2030 agenda for sustainable development.