Hazards

Information on natural hazards that triggered or had the potential to trigger natech events are stored in the hazard records. Description, location, extent, and characteristics of hazards can be specified. Besides historical hazards, the system also allows scenario hazards to be defined, which can be used for risk as-sessment purposes. Historical hazards are real hazards that occurred in the past, whereas scenario haz-ards are user-defined and fictitious hazards. The hazard record type is one of the main record types of the system.

The data fields of the hazard records are listed in Table 1.

Table 1. Hazard data fields

For each hazard, the hazard type, a descriptive name, and the occurrence date should be specified. For minor earthquakes, it is common practice to use the Flinn-Engdahl region name of the earthquake as the name. The hazard type determines the hazard parameters, which can be entered for the hazard. The status of the hazard can be indicated either as historical or scenario. Structurally they are equal, but they differ in their purpose of usage. Historical hazards are mainly used to validate the natech risk as-sessment methodology of RAPID-N, while scenario hazards can be used to assess the vulnerability of plants to natech risks and to evaluate the effectiveness of various engineering and design decisions in terms of prevention and mitigation.

If the occurrence time of the hazard is known, it can be specified explicitly. The time should be in UTC to prevent possible confusion among the records due to location-specific time-zone settings. The location of the hazard can be stated by country and province. The country list is linked to the map and updates the map extent to display the selected country. The source location of the hazard can be indicated as latitude and longitude, either by manual entry or by marking on the map. See the "Mapping" section for more details on mapping support of the system. Besides the country of origin, other countries affected by the hazard can be specified by selecting appropriate countries in the "countries affected" list. Af-fected countries should be unique.

Detailed information on hazard parameters (e.g. magnitude, intensity) at the origin can be specified by using the generic property mechanism of RAPID-N. Depending on the hazard type, the system only lists hazard properties that are available for the hazard type. Hazard parameters should be unique, but fuzzy numbers can be specified for numerical parameters. By using the property estimators, missing hazard parameters are calculated wherever possible. For earthquakes, the system has the capability of auto-matically defining and updating hazard parameters by using earthquake catalog data. Details of this functionality are given in the "Earthquake Catalog Data" section.

Records, which are related to the hazard, can be accessed from the hazard information page. Hazard maps, which contain regional (on-site) hazard parameters available for the hazard, are listed. For earth-quakes, catalog data of the earthquake can be accessed. Natechs that were triggered by the hazard and risk assessments performed for the hazard are displayed if they exist (Figure 1).