River Bank Instability Detection and Monitoring Assessment

One principal cause of river bank collapse is the removal of more sediment from stream banks than the system can replenish. This study aims to assess river bank erosion rate and erosion monitoring assessment for about ۳ km of the Shelie River. The primary data (more than ۲۰ River Bank and ۲۰ bed materials, ۱۰۴ river cross-sections were collected using standard surveying equipment. Sieve and hydrometer analysis were implemented. Secondary (metrological) data were collected from an Ethiopian national metrological agency. HEC-RAS model was used to compute the water surface profile and discharge-stage analysis. Additionally, BSTEM model was used to depict river bank migration rate and its stability analysis. BSTEM model result showed that left river banks are retreating laterally on average ۰.۰۱۲ m/hr for considered reach, and overall safety factor is greater than unity. Further, steady state flow simulation results confirmed that conveyance capacity of the considered reach is not enough to carry ۵۰-year return period design discharge and flood inundation raises a maximum of ۱.۲ m from normal flood level and extends ۲۰ m laterally.

کلیدواژه ها:

River ، Bank erosion ، BSTEM ، HEC-RAS ، Flood