MORPHODYNAMIC CHANGES INDUCED HUMAN DISPLACEMENT AND ITS CONSEQUENCES OF BHAGIRATHI RIVER AT INDO-BANGLADESH BORDER DISTRICT MALDA AND MURSHIDABAD USING GEOINFORMATICS

An attempt has been made to study one of the most severe and vulnerable catastrophes in West Bengal, India. Studies have been carried out to analyze and report the river bank erosion due to morphometric change of the Bhagirathi river, upstream of Farakka Barrage up to Rajmahal. Here Sinuosity, Braidedness Index, percentage of the island area to the total river reach area have been measured for the year of 1955, 1977, 1990, 2001, 2003, 2005 and 2010. The analysis shows a drastic increase in all of those parameters over the period of time. For increasing sinuosity, the river has been engulfing the large areas of left bank every year. The victims are mostly from Malda and Murshidabad district which have also international board and with Bangladesh. Toposheet of the year 1970 is also compared with the image data to observe the change. Water discharge, soil types and transportation of sediment is the major contributing factor of morphological changes like bar or shoal, ox-bow Lake meander etc. Another task of this study is to get the temporal shift statistics along each cross-section. This task has been followed by vulnerability analysis to assess the risk for the habitations for the next 10 to 20 years. These risk zones have been identified by applying linear regression method for each cross-section after proper validation. So, by risk zoning with the aid of remote sensing and GIS technologies, the study would help for better hazard prevention and preparedness programs beneficial to the socio-economic condition of the habitation which has an international character especially with Bangladesh area.