| Abstrakt: |
This study analyzed the flood risk associated with potential dam break events at the Pidekso dam in Wonogiri Regency, Central Java Province, Indonesia. Embankment dams, such as the Pidekso dam, are susceptible to piping and overtopping, which can result in dam failure and severe natural disasters, causing loss of life and infrastructure damage. The study utilized HEC-HMS and HEC-RAS software to simulate dam break scenarios, generating maps of dam break flood discharge, flood inundation, and flood arrival time. The analysis revealed that overtopping scenarios resulted in a higher outflow discharge compared to piping scenarios, with a peak discharge of 14,821 m3/s. Flood inundation and arrival time maps were used to assess the risks to nearby villages. Moreover, based on the risk index calculation using the formula provided by the National Disaster Management Agency, the studied villages were classified into distinct risk levels. Specifically, one very low-risk, four low-risk, six medium-risk, and seven high-risk villages, with none classified as very high-risk. This study also recommends a combination of structural and non-structural solutions to mitigate the risks of a dam break. By implementing structural mitigation measures such as an emergency spillway and compound channel along the downstream river, the study achieved an 8.4% reduction in flood extent. While most villages showed no significant changes in their risk indices, Sinorboyo village, which was previously susceptible to flooding, benefited from enhanced protection measures. [ABSTRACT FROM AUTHOR] |
