Flood hazard modelling and risk assessment in the Nadi River Basin, Fiji, using GIS and MCDA

Paquette, Jessy and Lowry, John (2012) Flood hazard modelling and risk assessment in the Nadi River Basin, Fiji, using GIS and MCDA. The South Pacific Journal of Natural and Applied Sciences, 30 (1). pp. 33-43. ISSN 1013-9877

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Abstract

This paper presents a simple and affordable approach to flood hazard assessment in a region where primary data are scarce. Using a multicriteria decision analysis (MCDA) approach coupled with GIS layers for elevation, catchments, land-use, slope, distance from channel, and soil types, we model the spatial extent of flood hazard in the Nadi River basin in western Fiji. Based on the flood hazard model results we assess risk to flood hazards in the greater Nadi area. This is carried out using 2007 census data and building location data obtained from aerial photography. The flood model reveals that the highest hazard areas in Nadi are the Narewa, Sikituru and Yavusania villages followed by the Nadi central business district (Nadi CBD). Closer examination of the data suggests that the Nadi River is not the only flood vector in the area. Several poorly designed storm drains also present a hazard since they get clogged by rubbish and cannot properly evacuate runoff thus creating water build-up. We conclude that the MCDA approach provides a simple and effective means to model flood hazard using basic GIS data. This type of model can help decision makers focus their flood risk awareness efforts, and gives important insights to disaster management authorities.

Item Type:	Journal Article
Subjects:	G Geography. Anthropology. Recreation > G Geography (General)
Divisions:	Faculty of Science, Technology and Environment (FSTE) > School of Geography, Earth Science and Environment
Depositing User:	Ms Shalni Sanjana
Date Deposited:	02 Sep 2013 04:04
Last Modified:	09 Jan 2017 20:54
URI:	http://repository.usp.ac.fj/id/eprint/6495

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