The LADM Valuation Information Model based on INTERLIS

Abstract

The geometric, legal, physical, economic, and environmental characteristics of property units are utilized in valuation activities. Property valuation registries and databases are supposed to record these characteristics in relation to property units that are subject to immovable property valuation. Moreover, the links between valuation registries and the other land administration registries such as cadastre, land registry, building and dwelling should be specified. Apart from procedural valuation standards, there is no internationally accepted data standard that defines the links and semantics of property valuation databases. The ISO 19152:2012 Land Administration Domain Model (LADM), as an international land administration standard focuses on legal requirements, but considers out of scope specifications of external information systems including valuation and taxation databases. A recently started joint activity under International Federation of Surveyors (FIG) Commission 9 (Valuation and the Management of Real Estate) and FIG Commission 7 (Cadastre and Land Management) has developed an information model for the specification of valuation information maintained by public authorities especially for property taxation.
This paper investigates the use of INTERLIS tools for the technical implementation of the Valuation Information Model, which has been developed as a valuation extension of ISO 19152:2012 Land Administration Domain Model (LADM).
INTERLIS is a Swiss standard that enables modelling and integration of geographic data sets. It provides a conceptual schema language that can be used to specify a data model in a neutral system environment, similarly, class diagrams of the Unified Modeling Language (UML). It is compatible with international standards like UML, XML and GML. INTERLIS also provide some tools for the implementation of conceptual models into technical models. The core LADM, a number of the ISO191xx base models and some LADM country profiles were already expressed in INTERLIS standard.
This paper presents definition of classes, code lists and constraints of the LADM Valuation Information Model and its Turkish Country Profile in INTERLIS. It also discusses possible advantageous of INTERLIS tools (UML editor, compiler, checker, validator and loader) such as system neutral data exchange format, compatibility with relevant international standards, reusable and extensible conceptual schema language, and automatic translation from the conceptual model to physical model.