Evaluating Urban Topography and Land Use Changes for the Urban River Management using Geospatial Techniques

Global freshwater excessive usage poses severe threat to human well-being and the environment. Maintaining the use of water becomes challenging due to population growth, changing hydrology, and climate change. With increasing land development and human activities in nearby and distant watersheds, the supplies of drinking water for cities are at threat due to potential contamination. India's 35% urban population generates almost 65% of the country's wastewater (NITI Aayog, 2022). This study focused the urban river management using geospatial techniques of the Dehradun Municipal Corporation (DMC) which has an area of 183.70 km² and its associated watersheds of Bindal River and Rispana River having an area of 44.40 km² and 58.09 km², respectively. The Shutter Radar Topography Mission (SRTM) DEM data with a spatial resolution of 30m has been used for the delineation of watershed boundary, drainage network, and identifying topographic features. Additionally, Sentinel-2 data with a spatial resolution of 10m has been utilized to analyse change in land use in 2017 and 2022. The drainage pattern in Bindal and Rispana watersheds were dendritic in shape with moderate relief. This study found, a significant decline in Agricultural Land from 17.94% in 2017 to 14.66% in 2022. This decline was accompanied by increase in Built-up area from 32.53% to 35.44%. The increased biotic pressure poses a critical threat to river health and biodiversity. This study highlights the urgent need of comprehensive river management strategies to efficiently monitor the biotic pressure due to transformation of land use. This research will be beneficial to diverse stakeholders, including decision-makers and urban planners engaged in sustainable management of water resources and urban development.