Short-Term Morphological Change Prediction of the Padma River at the Bridge Construction Location in Bangladesh

This study has predicted the short-term morphological changes of the Padma river at the bridge crossing illustrating the development and migration of bars, channels shifting and bank erosion using time-series satellite images. The three mid-channel bars MCB1, MCB2, MCB3 initiated with an initial area of 1.03, 1.89, 2.25 km 2 . After initiation, the MCB1 bar grew maximum size of 10 km 2 . The size of MCB2, MCB3 bars increased 3 to 4 folds within 3 to 5 years. At the initiation, the sizes of the four attached bars AB1, AB2, AB3, AB4 were very close and ranged from 3 to 6.7 km 2 . Among the four attached bars, the AB1, AB3 bars decreased in size and the AB2, AB4 bars increased from 4 to 10 folds in size. The three attached bars AB1, AB2, AB4 migrate with a very close rate of about 1.5 km/year while the AB3 bar showed no net migration within five years. Bathymetric surveys suggested the main channel has been continuing along the left channel close to Mawa and is going to take the shape of a single-channeled planform. The channels Ch1 and Ch2 along the right bank have not changed substantially from the previous years and the overall trend is decline in these two channels by 2011. The bar Br1 would move downstream and reach the bridge crossing by 2010. It is expected that the right flanking channel at the bridge crossing will be silted up; therefore, the bar Br2 would be an attached char.