The geographic information system (GIS) has a great role to play in disaster management activities at all stages of its operations. Disasters are emergency situations which cannot be managed locally. Disasters can be manmade or natural or combination of both. Geographic information system is used in all disaster management activities irrespective of its source as manmade or natural. GIS is stool which can be effectively used in disaster management activities in its all phases. It has a pre event phase, during phase and post disaster phase. Disaster preparedness required. Disaster management is altogether a cyclic operation composed of mitigation, preparedness, response and recovery. GIS can be effectively used in all these phases of operations and in most of the cases no other techniques can provide such solutions.
Mitigation is the advance prevention and identification of vulnerable zones so that emergencies cannot be turn into a disaster all together. Role of GIS in this phase is the map all vulnerable areas and safe areas in terms of all types of disasters. For this we need to identify all possible disasters in the area, classify them into zones of high risk, medium risk and low rick zones. Here lies the role of GIS. Through GIS technique available spatial domain can be classified. For example, in case of a floods from the major rivers, mapping and modeling using various themes and elevation data in the forms of digital terrain models will ease out in classification of high to low risk areas and provide in the form of map so that planners and decision makers can take better information based decision. SBL multidisciplinary geo spatial team can cater all such mapping and modeling services.
Preparedness phase of the disaster management also require geo spatial services. GIS will help in site selection of shelter areas, location for emergency resource storing facilities. Selection and modeling of evacuation routes is also can be done using GIS techniques. This include road capacity versus population size, direction of travel, where to place relief camps, identification of key tactical and strategic facilities, marking of nearest safe hospitals and public safely facilities. Identifying supply chain of relief materials and its pre routing, mass awareness and training to concerned officers and aiding agencies. The far most important part of GIS at this phase is that to identify the locations of impact, area it will influence, model to how it is spread etc. To achieve comprehensive preparedness, a great deal of information must be gathered and managed. When disasters strike, the right information must be available at the right place to support emergency decision requirements.
When an emergency strike an area, the already amazed spatial data can be effectively used to combat the disaster. Unfolding impact influence area, marking of areas in harm’s way and mass notification can be possible through GIS. Optimizing shelters, routings, estimating effected population and property, assessing quantity of relief materials, advance warnings to nearby possibly affected areas etc will be ease out with the help of GIS
GIS will act as a central data base repository during the recovery phase of a disaster. GIS couples with remote sensing act as an apt tool in assessment of damage and losses incurred. These kinds of spatial data assessment give information on degree of damage to individual properties and aerial extent of the damage. These will enable the planners and decision makers to estimate the reconstructions cost, prioritizing the areas for development.