Impact of land-use land cover dynamics on runoff in Panchnoi River basin, North East India

Abstract Alteration of land-use land cover pattern causes severe consequences on the hydrological system by modifying the rainfall-runoff pattern in a region. The study aimed to investigate the impact of land-use land-cover dynamics on runoff generation in different geomorphic divisions of Panchnoi River basin. The study used the Soil Conservation Service-Curve Number method to estimate runoff generation in the Panchnoi River basin in a GIS platform. This study observed that the conversion of the land-use pattern in the geomorphic zones significantly enhances runoff. The Piedmont experience highest land-use change, where 64.17 km2 forest cover lost to cropland and built-up lands, leads to a notable increase in runoff generation, i.e. from 1 076 mm (52.82% of rainfall) in 1990 to 1 467 mm (70.46% of rainfall) in 2015. The Flood plain and New alluvial plain generates high runoff in the basin as it mostly occupied by human-induced land-uses, i.e. 1 444 mm (72.72% of rainfall) and 1 360 mm (71.70% of rainfall) respectively in 1990, which increase to 1588 mm (79.20%) and 1507 mm (78.69%) runoff respectively in 2015, due to alteration of cropland to built-up lands. In the Old alluvial plain, a marginal land-use change observed resulted in moderate growth in runoff from 1 272 mm (62.35%) to 1 404 mm (66.79%). The study indicates land-use land-cover change invokes to increase runoff generation can give rise severe environmental and economic problems in the river basin, through the occurrence of flashflood and soil erosion. Highlights for public administration, management and planning: • Evaluation of the impact of land-use land cover dynamics on runoff is essential for containing flash flood and water resource management on a basin scale. • Alteration of natural land covers has severe implications in the form of flood, soil erosion, and loss of biodiversity. • Enhanced runoff due to land-use dynamics reduces groundwater recharge rate that may cause drinking water scarcity in the dry season shortly.