Impact of Urbanization on Surface Runoff Characteristics at Catchment Scale

Abstract

Increase in population and rapid urbanization are two main challenges to urban water management, especially for cities in developing countries like India. The assessment of changes in catchment surface runoff due to urbanization is critical for water resource planning and management. Uncertainty in rainfall and changing landuse pattern results from urbanization is difficult to correlate with present changing surface runoff conditions. This study has shown an approach to find a relation between these three by using a statistical term dynamic degree with application of the well-established tool, Curve Number (SCS-CN) method to observe surface runoff over the study area in conjunction with Geographic information system and remote sensing. This study assesses changes in runoff characteristics of Raipur catchment which has been delineated from a smallest sub-basin of Mahanadi River in Chhattisgarh, India. Pixel-based Runoff depth of each sub-catchment was estimated by incorporating digital elevation model, rainfall data, and Land Use/Land Cover (LULC) information for the years 1971–2015. Spatio-temporal variation in each sub-catchment has been computed and significant change in runoff has been observed. The motivation of this study aims to understand and to study the changing nature of urban growth pattern/sprawl, to quantify surface imperviousness and changes in surface runoff characteristics.