The Development of Ungauged-Catchment Integrated-Similarity Unit Hydrograph to Estimate Inflow of Wonogiri Reservoir

The Wonogiri Reservoir is a multipurpose reservoir at the Upper Bengawan Solo Watershed, primarily designed to serve as flood control system. However, there no accurate estimation of inflow into due limited availability hydrological stations. Observations showed only four out ten unit hydrographs watershed. Therefore, this study was conducted apply an integrated similarity-based approach for designing in ungauged catchments. process involved evaluating similarity between pairs gauged-ungauged catchments using hydrologic and physical property parameters. This led selection donor or gauged catchment with highest score develop hydrograph developed UHs were further applied estimate December 25, 2007, event. results that computed peak discharge 10.9% lower than previous study. Subsequently, HEC-HMS simulation model used project updated design reservoir. rainfall derived from automatic recorder (ARR) PERSIANN satellite-based data. ARR data extreme duration 5 hours while satellite indicated 6 hours. application 5-hour 5123 m3 s-1, 7041 10,370 s-1 60-year, 500-year, PMF floods respectively line criteria Reservoir. These estimates observed be significantly higher 1982 which 4000 5100 9600 respectively. important renew operation rule during periods.