ANALISIS DEBIT BANJIR PADA SUNGAI CICATIH DI WILAYAH KECAMATAN CICURUG, KABUPATEN SUKABUMI

Flooding is a hydrometeorological disaster that often causes significant losses in Indonesia, including in Sukabumi Regency. The flash flood in Cicurug District in 2020, caused by the overflow of the Cicatih River, resulted in severe infrastructure damage, loss of livelihoods, and impacted hundreds of families. This condition highlights the need for an in-depth scientific study of the Cicatih River flood discharge characteristics as a basis for effective flood control planning. This study analyzes the design rainfall and peak flood discharge of the Cicatih River using annual maximum rainfall data for the period 2015–2024 from the Ciutara Rainfall Station. Frequency distribution analysis was carried out using the Log Pearson Type III distribution, selected through Chi-Square and Smirnov- Kolmogorov goodness-of-fit tests, while flood discharge was calculated using the Synthetic Unit Hydrograph Nakayasu method. The results show that the peak flood discharge reaches 211.16 m³/second for the 100 year return period and 651.40 m³/second for the Probable Maximum Precipitation (PMP). The increase in discharge is closely related to land-use changes that reduce water infiltration capacity. Based on these findings, the recommended flood control strategies include structural measures such as levees or weirs and river normalization, as well as non-structural approaches such as soil and water conservation, flood hazard zoning, and strengthening of land-use management. The results of this study can serve as an important reference for sustainable flood management planning in the Cicatih River region.
Keywords: Rainfall, Flood Discharge, Log Pearson Type III, Synthetic Unit Hydrograph Nakayasu, Flood Control, Cicatih River.