Bank Erosion Pattern Analysis by Delineation of Course Migration of the Padma River at Harirampur Upazila Using Satellite Images and GIS Part II

Abstract

The river Padma had showed different planform pattern with the changes from meandering to braided, which varied spatially and temporally. Sequential left bankline migration of the Padma river at Harirampur upazila had been explored from topographic and aerial photography maps of 1765, 1860, 1925, 1943, 1952, 1963 and time series digital satellite images from 1973 to 2009, and also using geographic information services (GIS). The Padma was the narrowest channel in 1860 along Faridpur-Harirampur nodal line. The results by interpretation maps from 1860 to 1925 indicated that the left bankline migration of the Padma at Harirampur upazila was limited within a range of 2 km and it was limited to 2.6 km until 1963. But the river caused extreme bank line shifting towards the upazila around 10 km during 1973-2009 and created a deep embayment at this location. A particular erosion pattern developed a meandering bend and in one season, the lateral maximum highest erosion extent was 2200 m/year in 2000-2001. The left bank line has already started to retreat from Harirampur due to the development of a chute cutoff. The three locations (site 1, 2, 3) can be vulnerable to erosion by the construction of river training work at Mawa.