Meandering Bend Development Process at Mawa Reach of the Padma River

摘要

The river Padma developed a meandering bend at the right bank of Mawa reach (reach 2) in meandering platform stage. The bend development process started in 1992 and continued in full form up to 2000. Maximum lateral extension occurred 780 m/yr in 1995-96 and average lateral extension was 450 m/yr. During the bend development process the Padma eroded more than 12,500 ha landmass at the bend location. The highly erodible bank materials and river characteristics allowed the bend formation at this location. A good number of samples measurement of different time indicated that the meandering wavelength of the river reach varied from 30 to 40 km. The meandering width of the river reach was about 17 km in 2000. The bend sustained only for 8 years (1992-2000) and was not so concave but the bend has great significance upon the river training work like the constricting Padma River Bridge. Satellite images of CEGIS and several definition diagram models of meandering bend have been developed to explain the bend formation process and bend characteristics.