Natural and man-made flood risk mapping and warning for socially vulnerable populations

Abstract

Populations are usually unprepared for natural disasters (even in regions of high risk), and emergency planners are faced with the difficult task of evacuating these unprepared people quickly. Recent advances in Geographic Information Systems (GIS) technology allow for improved determination and mapping of risks for different natural and man-made disasters. Large amounts of data can be acquired, processed, analysed and displayed on digital maps, thus allowing the decision makers to assess the situation rapidly and take appropriate actions. Advanced hydrological tools for computation and modelling of natural hazards (such as floods) can be combined with GIS tools that have the capability of decision support and advanced visualization. This combination can be used to produce models that will represent the risks of natural and man-made disasters in the form of risk maps. Furthermore, these processes can be automated, which can allow for near real-time access to the risk maps. This can greatly help decision makers with emergency and mitigation measures, however the challenge is to design tools that meet the specific needs of emergency managers charged with the protection of a diverse and under-prepared populace. The research aimed to demonstrate the potential of GIS mapping tools with reference to two real case studies in Fredericton, New Brunswick, Canada. The first one relates to flood risk mapping needed for the evacuation of vulnerable populations, while in the second one, the mapping of a catastrophic flood scenario due to a dam break is presented. The results of both case studies has helped to identify that the evacuation of socially vulnerable sections of the population require more resources and emergency planning than the evacuation of the rest of population. The socially vulnerable population needs to be registered before the disaster occurs and their special needs need to be documented. The response time needed to evacuate people, especially those who are socially vulnerable is very important in saving lives. There exist a number of important factors when planning for an evacuation, e.g. The number of people to be evacuated, time available for the evacuations, the distance to travel and also the available routes for evacuation. The provisions of medicaments, special food and any additional resources have to be planned and prepared in advance. Here, the approach to identify, map and assist the evacuation of socially vulnerable population during flooding in Fredericton while taking care of their special needs is presented. The main result of this research is a web-based GIS system that provides appropriate information to the relevant authorities and general public in a timely manner and easy to understand.