Study on the channel migration pattern of Jia-Bhareli, Puthimari and Pagladiya tributaries of the Brahmaputra river using remote sensing Technology

Floods of high magnitude are one of the major problems in the north-eastern region of India. Heavy flooding causes abrupt changes in the flow pattern of the rivers. The present paper deals with the study of three northern bank tributaries of the Brahmaputra river, namely Jia-Bhareli, Puthimari and Pagladiya. The river Brahmaputra shows significant amount of erosion and deposition in the basin. Erosion is mainly caused by the rapid flow of water through soft, disintegrated rocks. Sporadic heavy downpours causes flash floods which also contributes towards erosion. Apart from all these, factors such as deforestation also contributes towards erosion. When the river enters the plain region with very gentle slope the velocity of water flow greatly decreases and the suspended load which is carried by the river gets deposited. This phenomena of deposition also contributes towards the change in the flow pattern and meandering of the river channel. Frequent Occurrence of high magnitude earthquakes are also responsible for the sudden and gradual change in the flow pattern of the Brahmaputra river and its tributaries. The main aim of the present study is to understand the problems caused by continuous change in the fluvial patterns of the river channels, amount of bank erosion and rate of sedimentation.