GIS-BASED TECHNIQUES TO IDENTIFY RAINFALL-INDUCED FLOOD RISK ZONES (BLUE SPOTS): A CASE STUDY OF BRUNEI RIVER CATCHMENT

摘要

Brunei continues to be inflicted by rainfall-induced floods that have been identified to be contributed by global climate change, increased population, developments, country's geography and her relative location in the Asia-Pacific region. By and large, floods cause detrimental effects on the country's social and economic health as well as damage to infrastructure and assets. Thus, it is becoming more imperative that a systematic study be conducted to identify the vulnerable locations (blue spots) in the flood-prone areas to help manage and mitigate the frequency and severity of floods respectively through engineering interventions. Using ArcMAP, the first goal of this paper is to determine the blue spots using planar spatial methods - Getis-Ord Gl* statistics using aggregated data from 2010 to 2018 for Brunei River. The second goal is to use HEC-RAS two-dimensional unsteady flow analysis will be performed to model a flood event of 50-year return period to predict the flood depths and extents. Ultimately, the blue spot mapping helps many relevant departments to steer towards preparedness, protection and prevention strategies.