A GIS-Based Hydrological Assessment of Urban Runoff in Shimla Using the SCS-CN Method

Urbanization in hilly regions like Shimla has significantly altered natural hydrological processes, leading to increased surface runoff and flood risks. This study presents a GIS-based hydrological assessment of urban runoff in the Shimla urban area using the Soil Conservation Service-Curve Number (SCS-CN) method. The research integrates remote sensing data, land use/land cover (LULC) classification, soil maps, and rainfall data to estimate runoff potential across the city. GIS tools were employed to spatially analyze and map hydrological parameters, enabling the generation of Curve Number values based on hydrologic soil groups and land use characteristics. The study reveals spatial variations in runoff potential, highlighting areas vulnerable to high runoff and surface flooding. Results indicate a strong correlation between increasing impervious surfaces and elevated runoff coefficients. This methodology provides a cost-effective and efficient approach for urban watershed management, offering critical insights for sustainable urban planning, storm water management, and climate resilience in mountainous urban environments.