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Emergency Management

CONTENTS• Definition

• GIS in Emergency Management and Related Area

• Key words in emergency management

• Case study

• Result

• conclusion

Definition

Emergency management defines as the discipline and profession of applying science, technology, planning, and management to deal with extreme events that can injure or kill large numbers of people, do extensive damage to property, and disrupt community life.

GIS in Emergency Management and Related Areas

The role of GIS in managing sudden impact disasters like flood and fires, rather than on slow onset hazards like radon gas,water pollution, land erosion, or other natural of technological hazards that occur gradually over time.

Preparedness is concerned with actions that are taken in advance of an emergency to develop operational capabilities and facilitate an effective response to an emergency.

Mitigation involves actions that are taken to eliminate or reduce the degree of long-term risk to human life and property from hazards

Recovery phase is characterized by activity to return life to normal or improved levels

Response phase involves actions that are taken immediately before, during, or directly after an emergency occurs, to save lives, minimize damage to property, and enhance the effectiveness of recovery.

GIS based Resource Management for Natural Hazards mitigation

Case study

To illustrate, a prototype implementation has been developed for Chennai city using Arc/Info

This involves location of emergency management facilities such as temporary shelters, medical relief centers, telecommunication facilities, food storage and distribution centers, etc. The resources required for managing disasters, such as food, medical supplies, vehicles

Vital time is lost in identifying the nearest facility and the best route to approach it which very often means the difference between success and failure of a rescue and rehabilitation operation.

METHODOLOGY

The network data model can be used for this purpose

A network is a system of interconnected linear features through which communication or transportation of resources is achieved.

The model consists of network links, network nodes, stops, centers and turns

Characteristics of a network model are Supply and Demand , Impedance

The network data model elements are Links, Turns, Stops, Centers, Barrier

Supply and Demand: For example: A hospital has a specific number of beds available this is the termed the supply.

Streets are assigned to the hospital until the total demand for those beds matches the supply

Impedance: Impedance is the cost associated with the utilization of the supplied resource through a network. Distance and time are commonly used impedance to the utility of the supply

For example no person living on a street farther than 20 minutes (through ambulance) may be assigned to that hospital.

Links: Links are represented as arc features and connect to each other at nodes. Connections between links are represented using arc-node topological data structure. Arc represents transportation links, and their attributes affect the movement of resources through a network

Turns: - The possible direction changes for resource flow every node where links connect. Flow can occur from one link through the node, and onto another link Particular tums often restrict flow in the network

Elements of Network data model

Stops: Node locations where resources are to be picked up or dropped off along paths through the network, Resource demand is the amount of resource associated with a stop.

Centers: Facilities at node locations which have a capacity to receive resources from links in the network, or distribute resources to the network. Example: hospital, school, etc.

Barrier: Node locations through which resources cannot flow. Barriers are the only elements Which do not have any attributes. Barriers are used to prevent movement between arcs

THE PROTOTYPE MODEL

• The bay area of Chennai between Royapettah and Parrys has been selected for the purpose of demonstration.

• This implementation is for cyclone disaster management, but it can be easily extended for other disasters as well. The bay area was chosen as it is the closest representation of a coastal zone within Chennai city.

Pxi = (Xi/ EXI)P1 +(Xi/∑Xr)Pr Nxi = df *Pxi

Where Xi - Length of the arc segment i.

EX' - Sum of lengths of all the segments of the polygon to the left of the segment Xi.EX- Sum of lengths of all the segments of the polygon to the right of the segment Xi.Pi- Population of the area to the left of X;

Pr - Population of the area to the right of Xi Nxi- Population along arc segment Xi who will be in need of the facility - Disaster Factor

For the example network given below, the demand is calculated as follows:

PX1(X7/X1+X2+X3)P1 (X7/XI+X5+X6)Pr = df * P x7

RESULT :The areas to be served by each hospital have been clearly identified (Figure 1).

It can also be noticed that some intermediate areas have not been allocated to either of the hospitals.

This is because the capacities of these hospitals have been exhausted before that demand could be met.

Based on multiple runs of the allocation program an optimal location has been identified for the location of an emergency medical facility such that the impedance is minimized .

Also the shortest route, taking barriers into consideration, has been identified for a sample location.(figure2)

CONCLUSIONS: (i) GIS is an appropriate environment for developing a decision support system for resource management for natural hazard mitigation.

(ii) The network module in Arc/info is ideally suited to address this issue. (iii) The primary challenge in developing an effective decision support system lies in assessing the needs of the decision makers and accurately acquiring, representing and updating the relevant data in the GIS.