Journal of Korean Society of Agricultural Engineers ISSN:1738-3692(Print) 2093-7709(Online) 한국농공학회논문집

This study proposes a novel methodology for indirectly estimating sediment deposition in aging agricultural reservoirs by analyzing water level fluctuation patterns. The approach was applied to Waryong Reservoir in Sacheon, Gyeongsangnam-do, using long-term hydrological observation data collected from 1997 to 2024. To classify rainfall events with similar rainfall and inflow characteristics, k-means clustering was employed, followed by Dynamic Time Warping (DTW) to group events exhibiting similar water level variation patterns. Events with comparable hourly rainfall distributions were then selected to calculate the Storage Response Index (SRI), enabling the identification of temporal differences in water level response patterns and the estimation of sediment deposition for specific storage ranges. Results indicate that approximately 48,930 m³ of sediment has accumulated in the 50–60% storage rate range, accounting for about 4.2% of the original design capacity. Comparison with water balance-based sediment estimation revealed a discrepancy of approximately 34,460 m³ within the same range. The proposed approach offers the advantage of estimating sediment volume without requiring detailed stage-storage survey data or precise bathymetric measurements. However, limitations arise from uncertainties in inflow and withdrawal data, as well as the limited number of suitable events. Future research should focus on applying this method to multiple reservoirs and validating its performance through quantitative comparisons with field measurements.