Understanding Morphological Dynamics of the Mahanadi River Reach

Abstract

Abstract This work examines specific river morphometry parameters like bank erosion, active channel bank shift, and the sinuous behavior at identified stretches of the Mahanadi River. The specific stretches of the Mahanadi River from Baipur to Gopinathpur, Cuttack of around 270 km have been subdivided into five different reaches to simplify the study from a large scale to an average range. The Digital Shoreline Analysis System was used to investigate the river bank shifting and for the bank shifting prediction using Kalman Filter Model. The outcomes of the work show that, for the most part, the Mahanadi River is sinuous; however, at Kantilo, which is designated as reach four is meandering. In terms of Sinuosity, most reaches are unstable, whereas reaches 2 and 3 are stable. The flow area ratio to channel area has fallen by 25-30% due to the construction of barrages and dams in the upper portion of the Mahanadi River, affecting aquatic life, people and industries. At the same time, due to climate change, irregular rainfall causes floods in the lower reach of the river. The river flow erodes the bank along which it flows, even when the discharge is minimal. According to the bank shift analysis, the right bank is more unstable, ranging from 222 to -2900 m, while the left bank fluctuates from 996 to -1600 m. This study will help to understand the pattern of river bank shifting and change in the planform dynamics at the respective locations of the Mahanadi River.