ANALISIS DEBIT PUNCAK SUNGAI AIR LELANGI TERHADAP ELEVASI DASAR JEMBATAN(Studi Kasus Sungai Air Lelangi Kabupaten Bengkulu Utara)

The purpose of this research was to analyze the peak discharge plan due to the intensity of rainfall in the Air Lelangi watershed in analyzing hydrology using Gama I and Nakayasu HSS. Based on the calculation of the frequency distribution of three rainfall methods, namely the method distributed by Type I Gumbel, Type Pearson Log III and Normal Log, the method used for calculating planned rainfall is the Type I Gumbel Method with a return period of 2, 5, 10, 25, 50 and 100 years, namely 25.91 mm, 59.84 mm, 82.30 mm, 110.69 mm, 131.75 mm and 152.65 mm. From the results of the hydrological analysis, the peak discharge in the Air Lelangi watershed for the 100-year return period with the Nakayasu HSS method is 725.73 m3 /sec with a peak time of 5 hours which is the largest peak discharge between HSS Gama I. For peak discharge results using the method HSS Gama I is 672.2 m3/sec with a peak time of 3 hours. Then the water level in the Air Lelangi watershed is 4.34 m