Many regions in the world are exposed to a number of natural hazards which cost billions of dollars annually. The growing impact of disasters in the past decades is mainly as a result of climate change. Out of 50 fastest growing cities in the world 40 of them are located in earthquake zones. More than 10 million people in developing countries live under constant threats of floods. To minimize disaster losses more efforts should be put in place on Disaster Risk Management, with a focus on hazard assessment, elements-at-risk mapping, vulnerability assessment and risk assessment, which all have an important spatial component.
Spatial information has a big role to play in impelling the decisions we make every day by giving a clear picture of the space around us. It allows us to identify the relationships and trends that were not apparent otherwise. GIS users are discovering increased use in risk analysis due to its capabilities in linking location with the associated information. It helps to efficiently capture, manipulate, store, and analyze information about geographic locations. One of the basic principles of risk assessment is that risks that happen due to natural catastrophes such as hurricanes, earthquakes, and floods are dependent on the location and can be assessed if reliable location intelligence is available. Considering this aspect, many institutions use GIS to assess the risk of life and property due to natural hazards.
GIS software companies such as Esri have developed methods that can help public safety agencies who respond to Natural Disasters through reducing their impact, providing first responders with the best information to make optimized safety decisions under stressful conditions, recovering from emergencies quickly and providing business continuity.
Forest fire is one of the natural hazards causing a huge life, property and ecology losses. These fires occur frequently and there is a need for supranational methods that analyse wide scenarios of aspects involved and global fire effects. Satellite data has been widely used to detect forest fires in different parts of the world and the Geographical Information System (GIS) and remote sensing techniques have been useful in assessing and predicting the fire frequency. It is impossible to control nature, but is possible to map forest fire risk zone and in that way reducing the frequency of fires. GIS can deliver tools to work with tactical, location-based information such as floor plans, utility control points, pre-fire plans, hazardous material contents and locations, surrounding exposures, aerial imagery, and hydrant locations. Access to this information allows firefighters to deploy more quickly, effectively, and, most important, safely.
GIS has proved useful in managing natural hazards such as floods. Flooding can be very perilous and can totally disturb public and personal transport by cutting off roads and communication channels when telephone lines are damaged. Several GIS models have been utilized in flood simulation, including the use of specialised GIS software like SOBEK, HEC-RAS, MIKE II, LISFLOOD, one-dimensional two-dimensional (1D2D) hydraulic and TUFLOW to mention just a few. Flood hazard assessment and mapping is used to identify areas at risk of flooding, and consequently to improve flood risk management and disaster preparedness. Flood hazard assessments and maps typically look at the expected extent and depth of flooding in a given location, based on various scenarios for example 100-year events or 50-year events. In Zimbabwe, the Civil Protection Unit has taken advantage of using GIS technologies to monitor flooding in areas such as Muzarabani, Zimbabwe Low Veld, Save and areas in Hwange District. Flood mapping exercises have been carried out to identify flood prone areas and evacuation centres. This makes the exercise an integral part of a flood early warning system and for emergency preparedness plan.
GIS provides an opportunity to civilian authorities and international agencies to boost their alertness for coping with natural disasters. GIS can help to manage the impact of earthquakes, hurricanes, avalanches and volcanoes. It also helps in assessing risk and hazard locations in relation to populations, property and natural resources, integrating data and enabling understanding of the scope of an emergency to manage the hazard, recommending preventive and mitigating solutions, determining how and where scarce resources should be assigned as well as prioritizing search and rescue tasks.
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