标题：Assessing the instability and shifting character of the River Bank Ganga in Manikchak Diara of Malda District, West Bengal using Bank Erosion Hazard Index, RS and GIS
摘要：In the present study, a method for developing a quantitative prediction of river bank erosion is
presented. A stream bank erodibility index was assessed to study the stability of the river bank.
To assess the stability of the river bank erosion hazard index (BEHI) was estimated in
consultation with bank height, bank slope, rooting depth, rooting density, and surface protection.
In the upstream of Farraka Barriage between Rajmahal and Farakka, the continuous shifting of
the left bank of the river Ganga and associated river bank erosion invited the loss of agricultural
land and socio-economic vulnerability in most of the Mouzas of Manikchak and Kaliachak block
of Malda district, West Bengal. In Manikchak block, 13 mouzas are severely affected by river
bank erosion. The estimated BEHI of Narayanpur, Manikchak, Gopalpur, and Duarni Tarif are
high which indicates the river bank instability. The satellite data of LANDSAT TM 5,
LANDSAT MSS 1 and LANDSAT ETM 7 for the year 1973, 1999 and 2011 were used to assess
the nature of shifting of the river bank and to estimate the land loss. All the derived images were
transported on GIS environment to extract the course of the river. To estimate the leftward
shifting of the bank line, 25 sites were considered along the left bank. Then overlaying the
extracted layers of the river course of the year between 1973 and 1999 and between 1973 and
2011, the distance of shifting of the river bank line was assessed. It is observed that there is a
strong relationship between bank instability, BEHI, shifting distance of the bank line and eroded
land area in the concerned study area.
关键词：Bank erosion; BEHI; bank instability; bank shifting; RS & GIS
