Cyclone disaster mapping, monitoring and management using satellite remote sensing and spatial analysis

Abstract

Tropical cyclones are one of the most catastrophic natural hazards regularly affecting tropical coastal areas globally. The overall impacts of tropical cyclones can be minimized using a range of management approaches, in terms of: prevention/reduction, and preparedness. Accurate and detailed spatial information on the natural and built environment is required to support the development, implementation and evaluation of these cyclone management approaches. There is a lack of appropriate mapping approaches and spatial models at local scales (<1000 km 2 ) to derive this information.This thesis developed and evaluated mapping approaches and spatial models at the local scale (<1000 km 2 ) by integrating remote sensing, field data and spatial analysis for assessing, monitoring and managing tropical cyclone impacts. Three specific objectives were addressed: (1) developing and evaluating an approach for assessing the multiple impacts of tropical cyclones through objectbased image analysis applied to moderate spatial resolution satellite imagery; (2) developing and testing a risk mapping approach for tropical cyclone impacts using an analytical hierarchy process (AHP) with data derived from remote sensing, field data and spatial analysis; and (3) producing and evaluating a simple risk modelling approach under present and future climate scenarios for tropical cyclone impacts using remote sensing, field data and spatial analysis. The developed mapping approaches and models were tested to justify the applicability in Sarankhola Upazila (151 km 2 ), a local government area in coastal Bangladesh. Cyclone Sidr (2007) was used as a case study for objective one in the study site.After introductory, review and research approach chapters, chapter four developed a method for mapping the multiple impacts of tropical cyclones. The object-based approach was used to map land cover types in pre-and post-cyclone Sidr (2007) damage to cropland and the changes to landforms. The damage results were verified using local damage reports and high spatial resolution satellite imagery that were taken after the cyclone.ii Chapter five integrated remote sensing, field data and spatial analysis for developing a multi-criteria tropical cyclone risk mapping approach at a local scale. Three risk components: 1-vulnerability and exposure; 2-hazard; and 3-mitigation capacity, and their 14 relevant criteria were considered.Thematic raster map layers were prepared for every criterion and weighted using AHP. A weighted overlay technique was used for generating vulnerability, hazard, mitigation capacity and risk maps.The verified results revealed that detailed cyclone risk information can be successfully mapped using geospatial techniques and an AHP at the local scale. The study found that incorporation of mitigation capacity significantly influenced the risk results. The approach also solved several issues for local level multi-criteria data generation, processing and integration. The approach provided was validated by confidence level assessment an...