Analisis Curah Hujan untuk Pendugaan Debit Puncak dengan Metode Rasional pada DAS Deli Kota Medan

Abstract

Rainfall Analysis using Rational Method is a kind of Hydrological Analysis which purposed to estimate peak rate in various repeated periods. Peak rate Estimation by this method needs rainfall data for 20 years to be analyzed step by step, starting from Statistic Parameters, Distribution of frequency, Test of Distribution and programmed Rainfall, until the value of Intensity (I) is found. Distribution model that is fitted to rainfall data is Log Pearson Type III distribution. Using the land use data and the characteristics of the River Basin, we can determine the value of Run off Coefficient (C) so that it was found that the run off Coefficient at Deli River Basin was physically is very good, because between 0-1%. The two parameters (I and C) were used to determine the peak rate of River Basin. It was found that, the peak rate of Deli river basin was 10650,9623 m3/second with rainfall intensity 2,5014 mm/hours in area of 56.622 km2 for 1 years. The used of this experiment for society and environment was as an important manual in constructing flood control structure and drainage channel in Deli River Basin in Medan.