Natural Hazard Susceptibility
INSPIRE is lacking the definition of susceptibility as a concept and feature type. Susceptibility is defined as the relative spatial probability of occurrence for a specific type of hazard, based on the intrinsic properties of a site (SafeLand, 2011). The concept of susceptibility differs from hazard in that the temporal probability of occurrence, the triggering factors, and the magnitude of the event are not considered in the definition of a susceptibility map (Van Den Eeckhaut and Hervás, 2012; SafeLand, 2011). The term susceptibility is mentioned in the INSPIRE data specifications for Natural Risk Zones, yet the concept is not implemented as a feature type. We extended the Natural Risk Zone Core XML schema to include this concept.
Two feature types have been added within the extension: Susceptibility Area and Abstract Susceptibility Area. The Susceptibility Area feature type is modeled following the structure of Hazard Area and Risk Zone feature types in the Natural Risk Zone Core schema. Susceptibility Area has three elements: Geometry, Influencing Factor and Relative Spatial Likelihood of Occurrence. Geometry, as for all INSPIRE vector datasets, is the geometric representation of the spatial feature.
Influencing factors are defined as the intrinsic, preparatory variables which make an area susceptible to a hazard. Influencing factors are unbounded in multiplicity and can be defined qualitatively or quantitatively. Qualitative influencing factors are expressed as a string, while quantitative influencing factors are express as GML:MeasureType. Whether defined quantitatively or qualitatively, the influencing factor can also define a DataSetType attribute, such as slope or air quality. Influencing factors are used in the calculation of Relative Spatial Likelihood of Occurrence, which is an element that can be quantitatively or qualitatively defined. The relative spatial likelihood of occurrence refers to values that represent the spatial probability of occurrence of a specific hazard type, given the influencing factors present in the area. The Influencing Factor element allows end users of Susceptibility Area datasets to understand which known conditions of the specific area resulted in the calculation of a particular Relative Spatial Likelihood of Occurrence. The schema extension can be found on Github. The schema is open-source (MIT licence) and we encourage the use of this schema for any natural hazard susceptibility mapping within the INSPIRE framework. Although this schema was developed for use in landslide susceptibility mapping it was designed to be applicable for any natural hazard susceptibility mapping application.