As the actual losses and the potential of both human and economic losses from disasters continues to rise globally, there is a growing recognition that disaster risk management efforts should be based on evidence of risk as opposed to only the perception of risk. The Sendai Framework states: “policies and practices for disaster risk management should be based on an understanding of disaster risk in all its dimensions of vulnerability, capacity, exposure of persons and assets, hazard characteristics and the environment.” Such an understanding of risk would inform all aspects of disaster risk management – prevention, mitigation, preparedness and post-disaster response and recovery. A systematic and periodic assessment of disaster risk will also help assess the efficacy of disaster risk management efforts including cost-benefit analyses.
Two broad work streams are identified in this regard:
- Assessment of disaster risk (potential losses): Disaster risk is the potential loss of life, injury, or destroyed or damaged assets, which could occur to a system, society or a community in a specific period of time. It is a function of hazard, exposure, vulnerability and capacity. With the knowledge of prevailing or emerging hazard patterns, exposed population, assets and economic activities, and their vulnerabilities, disaster risks can be assessed and mapped. Tools and techniques for assessing, mapping and communicating disaster risk have improved dramatically over the last two decades. However, application of these tools to generate easily understandable and usable disasters risk assessments is still in a nascent phase.
- Accounting of actual disaster losses: Assessment of potential losses needs to be complemented with tracking of actual losses. This requires systematic, geo-referenced disaster loss databases that capture losses at the lowest administrative level possible. Analysis of such databases will help discern the spatial and temporal trends in disaster losses. The Sendai Framework includes seven global targets. Four of these targets are pertaining to reduction in mortality, number of affected people, economic losses, and infrastructure losses. Progress against these targets can not be measured without robust disaster loss databases.
THE INDIAN CONTEXT
- With regards to development and application of disaster risk assessments, following broad observations can be made:
- At the National level, one of the earliest efforts to map disaster risk is the Vulnerability Atlas of India produced by BMTPC. It provides multi-hazard maps at the district level and superimposes the housing stock (categorized by roof and wall type) on these maps. Based on the generic vulnerability of each house type, loss scenarios can be estimated from the Atlas. The Atlas does not cover other capital assets such as transport, energy and communications networks, schools and hospitals.
- At the state level, a comprehensive probabilistic risk assessment was produced by Gujarat in 2005. In more recent years, Himachal Pradesh has undertaken such an assessment and produced an atlas accessible on a digital platform. A number of other states have undertaken hazard, vulnerability and risk assessments of varying scope.
- At the city level, a number of cities such as Shimla and Surat have undertaken detailed risk assessments.
- Progress has been made in improved hazard maps for almost all principal hazards: a number of cities have undertaken seismic micro-zonation studies; the country now has probabilistic seismic hazards maps; landslides have been inventoried using remotely sensed images; remotely sensed flood zonation maps have been produced for selected river basins. In general, mapping of exposure and vulnerability has not kept pace with progress on hazard mapping.
The above-mentioned efforts notwithstanding, the practice of comprehensive, probabilistic disaster risk assessment is still nascent in the country. There are numerous challenges with regards to disaster risk assessments such as:
- Common standards/ protocols for developing and periodically updating risk assessments at different scales;
- Inter-operable datasets on hazards, exposure and vulnerability;
Systems for making risk information available in an understandable and usable format to decision makers; and dialogue between producers and users of risk information
- With regards to accounting of disasters losses, following observations can be made: