Managing Disasters with GIS
Disasters such as Hurricane Harvey, the Mid-Western Floods of 2019, and the Camp Fire in California are catastrophic events that seriously disrupted the function of the communities they impacted. The disruption these events caused was driven by human, material, economic and environmental losses that exceeded the impacted communities’ ability to cope using its resources. Disaster management strives to reduce or avoid the potential losses from hazards, assure prompt and appropriate assistance to victims, and achieve an effective recovery. The conditions which lead to a hazardous event turning into a disaster are largely place-based. To carry out an effective disaster response, recovery and mitigation actions requires geographically referenced data (i.e., geospatial data) such as the location of a community, its critical infrastructure, and structures which house its population. To create, manage, analyze, and visualize geospatial data requires a collection of computer-based tools commonly known as a Geographic Information System (GIS).GIS coupled with remote sensing, scanning of the earth by satellite, aircraft or drones, provides a basic framework that can be leveraged to assist in all stages of disaster management.
Before the use of GIS in disaster management, response decisions were made based on prior experience and intuition rather than live data (i.e., real-time to most up-to-date data). Today, GIS web-services provide live geographic data (e.g., topography, population, infrastructure, demographics) and geophysical information (e.g., hurricane/storm tracks, radar measured precipitation, river and stream levels). GIS has the power to integrate data from various sources into a common platform and make it readily accessible to stakeholders. It enables dissemination of critical information promptly in cases of emergencies and the visualization of these data helps in analyzing a situation leading to quicker decisions.
Being prepared for a disaster requires knowing basic information like what, where, who, when and how
Preparedness and Mitigation
Being prepared for a disaster requires knowing basic information like what, where, who, when and how. What is the hazard that could trigger the disaster? Where are the people, critical infrastructure, location of buildings and shelters concerning the hazardous event? Who are the people going to be impacted and whose most at risk for adverse impacts (e.g., the elderly, children, the poor, recent immigrants, etc.)? When did the hazardous event occur? How frequently do these events happen? To answer these questions, GIS and remote sensing techniques can be used to build databases which contain information on critical facilities (i.e., hospitals, emergency responder stations, schools, etc.) which can help plan purposes. Also, maps can be prepared to show potentially hazardous areas in its relation to critical facilities and the built environment. For example, areas with high earthquake vulnerability, retrofitting of structures and enforcing strict building codes are necessary to mitigate against catastrophic damage. The governments and local agencies can preplan and improve preparedness by mapping evacuation routes, predetermine shelter locations, develop debris removal plans, stocking adequate supplies, and conducting response drills.
In many locations around the world, GIS-based decision support systems have been used to more effectively plan for and manage the impacts of disasters. Assessing the risk that a disaster may occur requires an understanding of the likely hood of such an event occurring in a given location and the magnitude of impact. These characteristics of a disaster need to be understood to make predictions about the impacts on the affected population, their infrastructure, and built environment. Mathematical modeling and GIS analytics are the backbones of these decision support systems. These platforms have been successfully implemented in several nations around the world and have been proven to be an impactful tool for mainstreaming disaster risk reduction. The predictions and geospatial data compiled for constructing these models also provide invaluable information for response to and recovery from disasters.
Responding effectively to a disaster requires critical place-based information such as where are the areas of damage, what is its intensity, what are the characteristics of the impacted population, and what kind of resources are needed to rescue and evacuate the affected individuals. GIS and remote sensing techniques can help answer these questions. For example, soon after a disaster strikes, use of remote sensing technologies, such as drone and satellite data, can be used to map the affected area, provide data to help determine the potential level of damage, and/or information about whether it is safe to return to an impacted location. GIS provides the analytical platform for performing damage assessments based off the remotely sensed data which provides crucial information to first responders such as estimates of the number of impacted persons, a number of casualties, and sheltering requirements for the affected population.
At the community level, GIS aids in the location and identification of critical infrastructure. Having a detailed inventory of the critical infrastructure allows for more rapid assessment of impacted components after a disaster and it provides for the prioritization of repairs which speeds recovery to vital lifelines such as communication, water, and power service. At the personal level, GIS parcel data provides property boundaries when all physical landmarks are destroyed in a disaster. Insurance claims are simplified when ownership can be established even when documents have been destroyed. Geographic details captured pre-disaster can be the difference between insurance claims being paid or denied.GIS platforms have also proven to be very useful in connecting separated families. Open applications with abilities to upload the photographs of missing family members and tagging the location of other family members have been applied for several disasters worldwide.
In our rapidly changing world with increasing global population and extreme weather events becoming more frequent and severe, the need for disaster management will only continue to grow.GIS will continue to be a fundamental tool for managing disasters. Government entities, academic institutions, private sector, and non-governmental organizations should work collaboratively to devise innovative tools and methods for improving disaster management strategies while taking full advantage of new developments in geospatial technologies.