SEDIMENTATION ANALYSIS ON SEYHAN DAM RESERVOIR USING LONG TERM BATHYMETRY DATA

Abstract

In this study, sedimentation in the Seyhan Dam reservoir was investigated by analyzing a long-term bathymetric survey dataset. The focus was on understanding how reservoir capacity changes impact reservoir operation rules. The findings revealed that sedimentation from the main branch of the Seyhan River has largely stopped since the construction of the Çatalan Dam, but sedimentation from the Çakıt branch continues. Furthermore, the study observed changes in the upper basin between 1990 and 2018 based on the CORINE Land Cover (CLC) dataset. The forest area increased from 23.71% to 24.36%, and water bodies expanded from 0.3% to 0.9%. This increase in forest and water bodies contributed to a reduction in sediment flow into the Seyhan Dam reservoir. The researchers used regression analysis and found a high correlation (R2=0.96) between water storage capacity changes and time (in years) at a 67.5-meter water level in the Seyhan Dam Reservoir. Overall, the study's results suggest that the decrease in sediment entering from the main branch of the Seyhan River has significantly improved the sedimentation issue.