Risk assessment in the Caribbean: modeling a GIS-based Flood risk Tool for Jamaica

The Caribbean is known to be one of the most hazard-prone regions in the world. Although the growing intensity of these disasters increases the concern of decision makers, researchers have not yet succeeded in developing an accurate multi-hazard risk assessment tool to locate the high-risk areas. Many single-hazard risk analyses adequately estimate the risk of one hazard, but the complexity of the relation between the different types of hazards causes difficulties in developing one risk analysis to assess all hazards. This research aims to develop such a model for the Caribbean. In a first step, a flood risk tool was developed for Jamaica. After optimizing this tool, the methods will be used for other hazard types. In a final step, all single-hazard tools will be combined into one multi-hazard risk assessment. To generate the flood risk tool, a new methodology based on minimizing risks rather than building water defences, was used. In the Flemish Region in Belgium, this method is already used in a tool called LATIS, and has proven that using a risk-based methodology helps tremendously in finding the most cost-efficient measures to reduce risk. For Jamaica, the lack of data was and is a big concern. Since there was only minimal rainfall data available, flood hazard maps could not be generated. Therefore, a risk map could not yet be computed, only a vulnerability map and a damage map could. Furthermore, the available damage functions did not cover all elements at risk. Before regenerating the damage map, these functions will have to be reassessed. However, the vulnerability map that was produced shows promising results in indicating the high-risk areas, which are the most important factor in the decision making process. Further research will focus on the flood hazard maps and the damage functions, before applying this method to other natural hazards

A GIS-based flood risk tool for Jamaica: the first step towards a multi-hazard risk assessment in the Carribean

The Caribbean is known to be one of the most hazard-prone regions in the world. Hurricanes, flooding, storm surges, earthquakes and landslides lead to extensive material, human and economic losses in the region. The growing intensity of these hazards, combined with the consequences of climate change, rapidly increases the concern among decision makers. Although many researchers have succeeded in developing a single-hazard risk assessment that accurately estimates the risk of one type of hazard, the complexity of the relation between the different types of hazards is causing difficulties in the development of a multi-hazard risk analysis. This research aims to develop such a model. In a first step, the consequences of each type of hazard will be assessed individually, starting with riverine flooding. In the next step, the methodology used in this tool will be assessed and modified to fit other types of hazards. Finally, all single-hazard tools will be combined into a generic multi-hazard risk assessment tool for the region. In Jamaica, local governments use a flood risk methodology that is based on building water defence structures to evacuate the water as quickly as possible. This methodology, however, causes bigger damages downstream. Another method, based on minimizing the consequences of the overall flood, is already in use in many countries. In the Flemish region of Belgium, it is implemented in a tool called LATIS and has already proven to decrease losses after a flood event. Therefore, this risk-based methodology is used as the base for developing the Jamaican flood risk tool. The biggest concern during this research is the lack of data in the region. The methodology used, is based on the Flemish flood risk tool and the acquired data is thus very elaborate. During the implementation of the methods for the Caribbean, especially the lack of sufficient rainfall data and adequate damage functions has proven to result in less accurate damage and vulnerability maps