The River Haora of Tripura State is a part of the Meghna Drainage System. In order to identify the nature of different bank materials and related changes in channel characteristics, an intensive field study was carried out in some selected parts of the River Haora in West Tripura District. The study area extends for a total stretch of 12.61 km from Reshambagan (23°50.208’N, 91°18.696’E.) in the downstream through Khayerpur (23°50.770’N, 91°20.709’E), Ranirbazar (23°49.679’N, 91°21.938’E), Mekhlipara (23°49.864’N, 91°21.639’E) up to Mohanpur (23°49.908’N, 91°21.639’E) in the upstream. Presence of sand, silt or clay makes the difference in the rate of liquefaction at the base of the river bank. Bank failure leads to change in channel characteristics through increase in sediment input, increase in channel width, decrease in channel depth, formation of mid channel bar, point bar etc. Moreover, human intervention leads to weakening of the bank base through illegal lifting of huge amount of sand using pumps. This activity leads to the draining out of bank toe materials towards the channel, thereby weakening of the bank base. During rainy season with increase in river stage (bank full discharge), the bank maintains an equilibrium condition with the pressure of river water. As soon as water level recedes, the equilibrium condition breaks down and bank failure takes place. The study reveals that the rate of failure is high at the sites where high percentage of sand is present in the middle or lower portion of the bank. Ultimately channel width increases and side by side changes in channel geomorphology leads to changes in channel cross-sectional area.
