Changing trends of channel pattern of the GangesPadma river

Abstract

This study analyzes the changing trends of channel pattern of the Ganges-Padma river. A time series of satellite images in the period of 1973-2006 are compiled for analysis. It is believed that the Ganges-Padma river is a meandering river. But lately the Ganges-Padma becomes braided river for high sediment transportation by Jamuna and deposition of Ganges-Padma river bed. For the purposes of study, the sinuosity ratio and braiding index were calculated in different time series. The analysis shows that the sinuosity ratio is increased over time. In 1973, it was 1.31 and in 1984, 1996, 2006 it was 1.33, 1.37, and 1.43 respectively. In 2006, though it was sinuous but it is very close to 1.5 which indicates meandering. In case of braiding index, it has been observed that in 1973, the braiding index was 1.3 and in 1984, 1996, 2006 it was 1.43, 1.62, and 1.92 respectively. The analysis also shows that in 1984, the braiding index was very close to 1.5. After 1996, it was exceeded 1.5 and continuously increasing. By analyzing the sinuosity ratio and braiding index, it has been observed that the changing rate of braiding index is more than sinuosity ratio.