Channel Dynamics
and Bankline Shift of the Brahmaputra River in Morigaon District, Assam
Saikia Ananya, Borthakur Monjit and Gogoi Barnali
Disaster Advances; Vol. 18(9); 60-80;
doi: https://doi.org/10.25303/189da060080; (2025)
Abstract
The Brahmaputra River, one of the biggest rivers in the world, has been alternating
between its two banks in north-south path of Assam, like a meandering river. Assam's
agro-climatic zones, particularly in districts like Morigaon, are largely influenced
by the River Brahmaputra, which causes regular flooding and bank erosion. This research
aims to evaluate channel change and bank line shifting of the River Brahmaputra
over 41 years, from 1980 to 2021, as well as the status and impact of bank degradation
from 2001 to 2021. The research is conducted using SOI toposheets and LANDSAT satellite
imagery from 1980, 2001 and 2021. To further evaluate the effects of bank erosion,
secondary data has been gathered from the District Disaster Management Authority
(DDMA) and the Revenue Circles (RC) of the districts. As per the records, out of
the five revenue circles (RC) of Morigaon district, the Bhuragaon RC, Mayong RC
and Laharighat RC have been facing bank erosion from 1980 onwards.
The Brahmaputra river channel is migrating more towards left direction than towards
right direction and the south bank line has been moving south in the district. The
three regions with the greatest bank line movement between 1980 and 2021 are Mayong
RC (5.34 km), Laharighat RC (5.32 km) and Bhuragaon RC (4.95 km). During the course
of twenty years, from 2001 to 2021, 3386.14 hectares of land in Laharighat RC were
lost to erosion, affecting 2583 households, of them 1427 lived on their own land
and 1156 on Government land. The erosion of 2499.90 hectares of land in Bhuragaon
RC has an impact on 2447 households who live on their own land. Similarly, 1520.1
hectares of land were lost in Mayong RC, affecting 3749 families in total, 200 living
on government land and 3549 on private land.
