Enhancing Riverbank Protection along the Jamuna River, Bangladesh: Review of Previous Countermeasures and Morphological Assessment through Groyne-Based Solutions Using Numerical Modeling

Abstract

This study investigated riverbank protection strategies along the dynamic Jamuna River in Bangladesh, a braided river prone to erosion and sedimentation. It reviews past countermeasures and emphasizes the effectiveness of groyne-type structures in redirecting flow and preventing erosion. Notably, the left bank exhibited greater stability than the right bank, emphasizing the need for effective groyne installations. A systematic methodology utilizing numerical modeling using International River Interface Cooperation (iRIC Nays2DH) ensured accuracy in assessing morphological impacts. This research presents novel countermeasures incorporating groyne installations along the right bank of the Jamuna River. Simulations are undertaken to assess the effectiveness of these measures under a range of flood scenarios, identifying a zone highly prone to erosion that exhibits the utmost vulnerability. The simulation scenarios comprised a base condition without groynes, two series of groynes separately placed in two selected zones, and a combined approach for both areas. Analysis of the four simulation cases, each encompassing three flood conditions, revealed that implementing two ‘I’-shaped perpendicular groynes in series within the erosion-prone area effectively diverted oblique flow. This approach proved optimal, mitigating erosion risk by redirecting flow and shaping sandbars along the Jamuna River’s riverbank. This study enhances Jamuna River protection, emphasizing groyne-type structures’ importance and promoting a holistic understanding of morphological dynamics for future river management and effective countermeasures.