ANALYSIS OF FLOOD SUSCEPTIBILITY BASED ON RASTER OPERATION METHOD BY USING GEOGRAPHIC INFORMATION SYSTEM

Abstract

Analysis of flood susceptibility based on raster operation method by using Geographic information System is focused on evaluating flood hazard by using GIS approach and analysis flood parameters that deal with field survey. Cempaga Catchment which is located on Kotawaringin Timur Regency and Katingan Regency, Central Kalimantan Province is part of Mentaya Catchment. Flood parameters used are slope, vegetation coverage, soil, drainage systems, and rainfall data. Raster operation is applied to achieve flood area susceptibility. There are several results that can be achieved from this research namely exploration flood susceptibility map and flood susceptibility map. Society information is needed to create a tentative map. It is functioned as explorative map to identify flood prone area. GIS technique is used to determine flood prone area both explorative map and susceptibility flood map. Binary and Ranking/Rating concepts are applied to determine flood susceptibility. Binary concept deals with two level of prone area such as secure and danger. It refers to society information and rapid assessment to categorize a flood level. Ranking and Rating method are dealing with value of each parameter which are causing flood. scoring is also applied to determine prone area. Parameters which are influencing flood susceptibility on Cempaga catchment are soil (Entisols), topography (slope below 2 %), geomorphology (close to fluvial processes: fluvial plain), landuse (agriculture and bush), and rainfall.