MORPHOMETRIC AND LAND USE ANALYSIS TO ESTIMATE FLOOD HAZARD – A CASE STUDY OF UPPER CIMANUK WATERSHED IN GARUT REGENCY, INDONESIA

Abstract

Flood is one of the most common hazards and the events have often occurred in the Garut
Regency, which can cause loss of property and human lives. Eighteen-four sub-watersheds has divided The
Upper Cimanuk Watershed based on three-order, selected as DTA01 to DTA84, for prioritization purpose. In
this study a flood hazard model in Upper Cimanuk watershed is examined based on the morphometric aspect,
combined land use analysis and the supplementary information regarding slope and rainfall. Each sub-drainage
basin was ordered into grades based on the considered compound parameter (Cp). These results define the area
flood hazard in prioritization map were divided into three zones: high, medium and low classes. Three distinct
measurements such as basic, linear (Rb, Dd, Lof, and T), and shape (Re and Rf) aspects obtained the
morphometric characterization over the 84 sub-watersheds. The prioritization results based on the connection
of morphometric aspects and land use only 12 sub-drainage basin considered as First priority, 9 sub-watersheds
considered as medium and 5 sub-watersheds considered as low priority. The result of this study can exact the
action to fix the possible hazard from floods in the study area.