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Hazard Risk Assessment

Ex ante risk assessment involves quantification of risk through understanding hazard, vulnerabilities and exposure patterns. This knowledge is essential for development of strategies and measures for reducing the risks.

On the other hand, post disaster loss and damage data provides information on number of people killed, injured, missing and/or loss of and damage to physical assets, and serves as input for estimating loss and damage associated with the hazards. Development of such databases requires georeferencing with the hazard event (natural, human-made, etc.).

Risk identification provides the first essential step for development of sound risk management strategies. A fundamental requirement is the availability of historical and real-time, systematic and consistent, observations of hydro-meteorological parameters, complemented with other forecast products providing information on expected patterns of hazards from the next hour to longer time frames. This must be complemented with vulnerability and exposure information, tools and methodologies for hazard analysis, mapping as well as sectoral risk assessment and modelling.





  • Atlas of Mortality and Economic Losses from Weather, Water and Climate Extremes (1970–2012), a joint publication of WMO and CRED.


Hazard events are characterized by magnitude, duration, location and timing. Calculating the probability of occurrence of hazard events in terms of these characteristics is the key in understanding fully the hazard component of disaster impacts. These defining characteristics provide a basis for extracting information on hazard frequency and severity from observational datasets. The fundamental requirement is the availability of, and access to, high quality historical meteorological and hydrological data that is provided by the National Meteorological and Hydrological Services (NMHSs). This requires:

      • Ongoing, systematic and consistent observations of hazard-relevant hydro-meteorological parameters;
      • Quality assurance and proper archiving of the data into temporally and geographically referenced, and consistently catalogued, observational datasets; and
      • Ensuring that the data can be located and retrieved by users

In the 2006 WMO Disaster Risk Reduction (DRR) Capacity Assessment of NMHS in Support of Disaster Risk Reduction indicated the need for strengthening their observing networks, capacity for maintenance of standard hazard databases and metadata, maintenance of sectoral disaster loss data, and, methodologies for risk modeling to support development planning in different economic sectors. Given the pervasive nature of hydro-meteorological hazards and increasing levels of exposure and vulnerability, risk identification will requires continuing and renewed commitment to maintaining the observing networks, basic data, and hazard forecasting capacities.

WMO DRR Services Activities related to hazard risk assessment
WMO DRR services Division has established the Expert Advisory Group on Hazard/Risk Analysis (EAG-HRA) (the first meeting was held in September 2012) to focus on issues related to standards and guidelines for hazard definition, classification and standardization of hazard databases, metadata and statistical and forecasting techniques for hazard analysis to support loss and damage data collection and risk modelling.

As a first step WMO DRR Services Division in partnership with the Centre for Research on the Epidemiology of Disasters (CRED) of the Université Catholique de Louvain (UCL), one of the leading custodians of global disaster impact databases, is in the process of development of a joint WMO / CRED annual report on the impacts of meteorological, hydrological and climate-related hazards with the goal of producing a prototype report for the year 2011 by the fourth quarter of 2012.

WMO Meetings and associated websites related to hazard risk assessment




Final Report

WMO User Workshop: “Requirements for Weather, Climate and Hydrological Services to Support Loss and Damage Data Collection and Risk Modelling ” London, United Kingdom 4 July 2014  
Understanding Risk Forum London, United Kingdom 30 June-
4 July2014

2013 (1st) Meeting of Disaster Risk Reduction Focal Point of Technical Commissions and Programmes

Geneva, Switzerland

14-16 October 2013


First Technical Workshop on Standards for Hazard Monitoring, Databases, Metadata and Analysis Techniques to Support Risk Assessment

Geneva, Switzerland

10-14 June 2013












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