STUDI REGIONALISASI DAS-DAS DI JAWA TIMUR: ANALISIS FREKUENSI BANJIR

Abstract

This paper aims to analyze the frequency of flooding and describe the relationship between physical and hydrological characteristics of the watersheds in East Java in order to study regionalization. The study was conducted by sampling the data at 15 watersheds in East Java. Research methods include: (1) inventory data, (2) calculation of the physical and hydrological characteristic, (3) flood frequency analysis, and (4) statistical analysis. Physical characteristics that were analyzed include: watershed area, length of main rivers, Drainage density, etc. Flood Frequency Analysis conducted by the Log Pearson III method. Regionalization carried out using the method of Direct Regression. The results showed that the physical and hydrological characteristics of the 15 watersheds are very diverse so it is difficult to be expressed in relation to declare certain degree of order. Nevertheless, some form of graphs can be used to estimate the pattern of relationships between physical characteristics and watersheds, so that it appears some physical characteristics that can be used as the basis for the classification of the watershed. Regression analysis produced by Direct Regression equations and coefficients that can be used as a basis for determining the frequency of floods for watersheds that has not been measured in East Java.