Geomorphological Explanation of Swamps along the Brahmaputra River Channel, Assam

Wetlands are conspicuous features of the Rood plains along the Brahmaputra River, Assam. The sequential change in numbers and areas of wetlands (Bils) for a stretch of 260km have been studied using available topographic maps of the Survey of India (1914,1975) and Indian Remote Sensing satellite imagery (1998). The total number of swamps as evident from the study was 529 in 19 14,783 in 1975 and 781 in 1998. Moreover, total areas covered by the wetlands as observed was 93.73 km² in 1914, 161.23 km km² in 1975 and 182.73 km km² in 1998. The low lying nature of the basin, shifting of river channels in a relatively short span of time, associated tectonics of the region and allogenic processes in relation to flood control measures adopted have played a major role in extensive changes to the wetlands over this period. The data presented here aid in formulating an effective flood control strategy to be adopted for this perennial flood prone area, stabilisation of landforms and different wetland management approaches.