Estimation of EIA by Semi-Automated Direct Method for Western Indian Urban Catchment Area

Abstract

Urbanization impacts water resources, with impervious surfaces indicating the degree of disturbance. Effective impervious area (EIA) is a better measure than total impervious area (TIA) for urban runoff. EIA is the portion of TIA connected to the storm sewer system. Remote sensing data alone is insufficient for EIA determination. An alternative approach integrates remote sensing data with drainage networks to ensure connectivity of impervious surfaces. This approach uses GIS data including multi-sensor data. The modified literature algorithm was used in python to analyze the study area. It is observed that for western Indian urban catchment area, some empirical equation such as Sutherland’s and Alley-Veenhuis showed under-estimation and over-estimation at some watershed parts which were obtained using DEM delineation. Based on the results obtained from proposed method, a quadratic relationship was established between easily measured TIA and hydraulically relevant EIA for an urban catchment in western India. These outcomes should result in more effective and properly designed SCMs, with potential improvements in water quality and cost savings.