Vulnerability is generally referred to as the inability of people, organizations, and societies to withstand adverse impacts of multiple stresses to which they are exposed. It is based on the premise that though different groups within a society may have the same level of exposure to a natural hazard, it may have a varying consequences for each of these groups, since they have diverging capacities and abilities to handle the impacts of such a hazard. Therefore to assess vulnerability there is a need to understand the conditions that make exposure of an individual or a community or a region unsafe, leading to vulnerability and the causes leading to creation of these conditions. There are many aspects of vulnerability, arising from various physical, social, economic, and environmental factors. Examples may include poor design and construction of buildings, inadequate protection of assets, lack of public information and awareness, limited official recognition of risks and preparedness measures, and disregard for wise environmental management. Thus vulnerability assessments would require systematic examinations of population groups, building elements, facilities, or components of the economy to identify features that are susceptible to damage from the effects of natural hazards.
ArcGIS software provides an efficient way to identify natural hazard-prone areas and vulnerable populations, structures, and resources. This is done by combining or layering engineering data, such as buildings and roads, natural hazard data, such as earthquake zones, flood zones, fire risk areas and other data, such as temporal distribution of population and community facilities. Huge volumes of data are compiled on various parameters and are presented through maps which reveal spatial relationships between different attributes. The resulting maps projects patterns or trends can be helpful to the planners, engineers, disaster prevention and rescue officers and NGO’s. In this study, the methodology for assessing the infrastructure and transport vulnerability