ANALISIS DISTRIBUSI CURAH HUJAN MENGGUNAKAN METODE LOG PEARSON III

Raymond Pasaribu (Civil Engineering, Faculty of Defense Engineering and Technology, Republic of Indonesia Defense University, West Java, Indonesia, 16810)
M Kaysan Nawfal (Civil Engineering, Faculty of Defense Engineering and Technology, Republic of Indonesia Defense University, West Java, Indonesia, 16810)
Oersted Melkgior Siburian (Civil Engineering, Faculty of Defense Engineering and Technology, Republic of Indonesia Defense University, West Java, Indonesia, 16810)
Anasya Arsita Laksmi (Water Resources Engineering, Faculty of Defense Engineering and Technology, Republic of Indonesia Defense University, West Java, Indonesia, 16810)

Jurnal Teknik Sipil Cendekia (JTSC)
Vol 7 No 2 (2026): May

Rainfall frequency analysis is essential for determining design rainfall and flood discharge in hydraulic structure planning. In this study, annual maximum rainfall data were evaluated using statistical parameters—including the coefficient of variation, skewness coefficient, and kurtosis coefficient—to determine the most suitable probability distribution. The Log-Pearson Type III distribution was selected as it best represented the historical data patterns. Design rainfall values for various return periods were subsequently computed to construct Intensity-Duration-Frequency (IDF) curves. Watershed delineation was performed to identify the physical characteristics of the river basin, allowing the transformation of design rainfall into peak flood discharges. The results demonstrate that longer return periods consistently yield higher rainfall intensities and peak discharges. Ultimately, this study provides critical hydrological parameters required for effective drainage design and regional flood control.