Impact of the Change in Topography Caused by Road Construction on the Flood Vulnerability of Mobility on Road Networks in Urban Areas

Abstract

In urban watersheds, floods directly affect mobility on road networks. The present study proposes a methodology for analysing the impact of road construction or reconstruction on topography and, ultimately, on causing floods. The study first proposes a methodology to estimate the vulnerability to mobility on road networks due to flooding, illustrated on a road network in Nagpur city in central India. The study proposes the flood vulnerability road mobility index (FVRMI) through hydrologic modeling using parameters such as precipitation trends, the land use function, elevation models generated by satellite data, flood inundation depth calculated using the soil conservation service curve number (SCS-CN) method, a time area histogram, and the flood-safe driving speed of a road network. Then, FVRMI was estimated for the changed topography observed through elevation models generated by satellite data due to road reconstruction from 2010 to 2018. Results show that this has affected the flow regime of the Nagpur urban watersheds. The estimated FVRMI was 20% higher for the changed topography in 2018 (Model II) than the topography scenario of the base year, 2010 (Model I). The results show that about 63% of road segments had a higher FVRMI value in 2018.