Permodelan kurva regresi intensitas-durasi-frekuensi (IDF) Provinsi Kalimantan Selatan berdasarkan analisis curah hujan ekstrim

Abstract

The development of industry resulted in decreasing infiltration rate of soil and the rain will form the surface runoff water flow. The curve relationship between intensity, duration and frequency (IDF) became one of the analysis that can be used in engineering management and control of water resources. IDF curves established from the results of Equation Mononobe regression with rainfall intensity variable, rainfall duration variable (5, 15, 30, 60, 120, 240, and 360 (in minutes)) and frequency variable (2, 5, 10, 20, 25, and 50 (annual)). The rainfall intensity based on extreme daily rainfall prediction using Gumbel Distribution. Extreme daily rainfall data of the 13 rain gauge stations from 13 cities/counties in Kalimantan Selatan Province averaged by Thiessen Polygon Method where average calculation method using the weighting based on the area of influence of each rain gauge station. The average extreme daily rainfall in Kalimantan Selatan Province from the year 2005 up to 2014 is 320.91 mm. The result of IDF of each frequency curves logarithmic trend. The highest rainfall intensity is 759 mm/hour (duration: 5 minutes, frequency: 50th annual) and the lowest rainfall intensity is 33 mm/hour (duration: 360 minutes, frequency: 2nd annual). IDF curves in Kalimantan Selatan Province referable in the design and planning of activities related to the management and control of water resources in development activities and industry.