Hydrogeological Fiat Features
Fiatness, like fuzziness, can pertain to spatial and temporal boundaries, as well as to non-geospatial characteristics typical of a given feature. Fiatness, in this case, means the arbitrary definition of something that does not exist objectively in reality, but without it something that exists in reality cannot be properly defined or classified. Fiatness often pertains to the relation between a geospatial feature and something else, e.g. a non-geospatial object. Examples of fiat boundaries are horizons, boundaries of administrative units or boundaries of geodetic parcels.Agood illustration is the case of a sea gulf. On the land side, the gulf is limited by a genuine, sharp boundary — the shoreline, but on the open sea side, there is no genuine boundary. Therefore, some arbitrary line is defined, which separates the gulf from the open sea. This is a typical example of a fiat boundary.
In hydrogeology, as in geology, most spatial boundaries are fuzzy, which is caused either by actual fuzziness of these boundaries, or by a lack of information regarding their actual position (apparent fuzziness), or by the necessity to separate a part that is not clearly defined from some entity. The method of determining such boundaries depends mainly upon the feature type and the knowledge that we have with regard to this feature. The most popular hydrogeological fiat features are, among others, subtypes derived from the primary type “area of (x) of
groundwater”, e.g. area of (deficit) of groundwater, area of (protection) of groundwater etc. This group also includes all 21 subtypes of zones, e.g. zone of influence of a well and many other, such as depression cone, groundwater deposit, hydrogeological region and groundwater province.
Reference : Janusz Michalak, Faculty of Geology, Warsaw University
Tags: fiatness, groundwater, groundwater province, hydrogeological fiat features, hydrogeological region