Analysis of bed changes in the segment of the Tien river flowing through Tan Chau

Abstract

Abstract The segment of the Tien River flowing through Tan Chau town is a meandering section with complex flow patterns, influenced by the flow dynamics and the lack of upstream sediment supply. This has resulted in the formation of deep erosional channels that affect the bank stability. This study focuses on evaluating the bed change of the Tien River within Tan Chau town through the analysis of measurement data and some scenarios from numerical modeling. The findings reveal that the Tan Chau - Hong Ngu curved section experiences severe channel erosion, particularly concentrated in the topographic channel and inclined towards the concave bank of Tan Chau (the inner bank). An analysis of causative factors indicates that reduced sediment supply due to dam construction and sand mining activities have led to changes in the riverbed, deeper erosion, and bank erosion near the sand mining area. The results quantifies the sediment deficit in the area at 0.86%, while the impact of sand mining in this area is 0.26%. The findings from this research provide a database to support local planning for bank protection projects and disaster mitigation measures due to bank erosion.