Title: Estimation of rainfall-runoff potential using SCS-CN and geospatial approach for Loktak Lake Watershed, India

Authors: Ranu Jajo Laishram; Wazir Alam

Addresses: Department of Forestry and Environmental Science, Manipur University (A Central University), Canchipur, Indo-Myanmar Road, Imphal 795003, India ' Department of Forestry and Environmental Science, Manipur University (A Central University), Canchipur, Indo-Myanmar Road, Imphal 795003, India

Abstract: Rainfall and runoff are important hydrologic variables that determine the spatio-temporal availability and distribution of water resources. The Loktak Lake Watershed is an important ungauged catchment of Manipur, India, where the runoff behaviour has not been well documented due to constraints involved in its direct estimation. Therefore, the present study uses the soil conservation service curve number (SCS-CN) method by integrating geoinformatics tools to estimate the potential runoff from Loktak watershed. The assessed land use/land cover changes of the catchment area during 2000 to 2020 illustrate significant increase in urbanisation/built-up area (10.67% to 19.95%) and decrease in forest cover (25.86% to 24.49%). The estimated total potential runoff depths during the study period ranged from 118.21 mm to 996.88 mm, with highest runoff observed in 2017. Average annual proportion of rainfall converted to runoff was around 25.9%, and highest average monthly runoff was observed during June and lowest in January.

Keywords: runoff; watershed; SCS-CN; land use/land cover; LULC; geographic information system; GIS; remote sensing; India.

DOI: 10.1504/IJHST.2024.139434

International Journal of Hydrology Science and Technology, 2024 Vol.18 No.1, pp.77 - 105

Received: 13 Jun 2022
Accepted: 09 Mar 2023
Published online: 02 Jul 2024 *

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