Quantitative Assessment of Channel Migration in the Ghaghara River, Ganga Plain, India

The Ghaghara River is one of the longest tributary of the Ganga River. The Ghaghara, a snow fed river is well known for channel shifting/migration. It was analyzed for lateral migration using multi-temporal satellite images and SOI toposheets. It shows 4.2 to 6.1 km lateral migration in last 45 years (1975–2020) between Bahraich and Deoria in the state of Uttar Pradesh. The lateral migration on the left side of the river (NNE) is 6144, 4838, 6475 and 4755 m, whereas on the right side (SSW) is 7021, 4555, 4718 and 4257 m during 1975–1990, 1975–2000, 1975–2010 and 1975–2020, respectively. The rate of migration (m/year) on left side (NNE) is 410, 194, 185 and 106, whereas on the right side (SSW) is 468, 182, 135 and 95 during 1975–1990, 1975–2000, 1975–2010 and 1975–2020, respectively. The major factors such as heavy precipitation, reactivation of chute channels, deposition of sediments, breaching of embankments and sand mining etc. might be responsible for the lateral migration of the river. Human settlements should be constructed away from the migration-prone area and regular monitoring and management system needs to be in place to mitigate the impacts of such natural events.