Article

A ‘For Dummies’-style introduction to LADM

How can the conceptual Land Administration Domain Model (LADM) be applied to different scenarios? The FIG book titled LADM in the Classroom provides examples, as well as guidance for using the book and other resources for further skills development.

Earlier this year, FIG published the book titled LADM in the Classroom. In the style of that book, this article gives an overview of the Land Administration Domain Model (LADM), showing how the conceptual model can be applied to different scenarios by way of example. It also provides guidance on how to use LADM in the Classroom and associated materials to further develop LADM competencies.

Information is the fuel on which all land administration processes run. Simply put, the execution of a land administration process is the flow and transformation of land-related information within and between organizations tasked with the determination and/or enforcement of the legitimate use of land.

This flowing of information must be consistent if it is to be relied upon by different organizations (and the public), and any transformation thereof must be based on transparent and deterministic (predictable) rules or procedures. However, land administration archives and document repositories tend to grow over time and, due to the complexity of land information, become increasingly difficult to search and maintain.

LADM in a nutshell

The Land Administration Domain Model (LADM) is a conceptual model designed to support the development of land information systems (LIS) including software applications, workflows, databases and user interfaces, in a way that addresses these challenges and more. LADM is an international standard published by the International Organization for Standardization (ISO) as ISO 19152. The first edition was published in 2012 and the publication of a second, multipart, edition is nearing completion. The standard specifies a collection of land administration concepts common to most land administration systems (LAS) across the world, as well as relationships between these concepts. It provides the most complete template for how land administration information can be organized to meet LAS needs. LADM Edition I forms the focus of this article and of LADM in the Classroom, published by the International Federation of Surveyors *(*FIG) in April 2025. LADM Editions I and II are backwards compatible.

Technically, LADM is realized as a Unified Modelling Language (UML) class model. It organizes land information into three main groups or ‘packages’: ‘Party’ (all records related to entities involved in land administration procedures, including private individuals or collectives and public officers and institutions), ‘Administrative’ (all records related to administrative handling of rights, responsibilities and restrictions [RRR]), and ‘SpatialUnit’ (all records related to pieces of land or eligible surfaces and three-dimensional spaces that are – or can be subject to – land rights claims).

Figure 1: Cadastral map of a fictitious village used to illustrate LADM concepts (above) and a triple of Party-RRR-SpatialUnit (below) illustrating a land tenure record.

Putting LADM into practice

So how can data be structured using LADM as a template? To illustrate the application of LADM, the book* LADM in the Classroom* introduces a fictional settlement: the small village of Waterriver. The material does not assume UML knowledge or specific technical skills. The map in Figure 1 represents the set of parcels recorded in the Waterriver cadastral database. It uses a basic template with the following structure: Party has Right/Restriction/Responsibility (RRR) on SpatialUnit. Even with this simple example, several cases can be demonstrated.

Multiple spatial units

The citizen in Figure 1, Carlos, is the only party with a right on one spatial unit. But what if a party has rights on more than one spatial unit? LADM supports bundling together multiple spatial units linked to the same party using the concept of a Basic Administrative Unit (BAUnit).

This can be represented by the diagram below the map in Figure 2. The Municipality of Waterriver holds ownership rights on spatial units WR03, WR05, WR06, WR07 and WR016. These are bundled together under BAUnit BAU03. The labels are identifiers which should be unique within the LIS. The spatial units are of different types (roads, parcels designated for business purposes, a water body) but the municipality holds a uniform ownership right on all of them.

This ‘instance diagram’ can be thought of as a simplified form of the similar version in the case of Carlos in Figure 1. The icons have been replaced by simple rectangles labelled with the represented record’s identifier. For readability, all entities from the Party package are shown in green, the Administrative package in yellow, and the SpatialUnit package in light blue. This diagram also corresponds to how records are stored in the database.

Figure 2: Multiple spatial units on which are associated a single party has uniform rights are bundled into a BAUnit.

Multiple parties, multiple rights

In most cases, not only is there more than one spatial unit involved, but multiple parties might have multiple rights to the same or different spatial units. As illustrated in the LADM instance diagram below the map in Figure 3, Anna acquired the parcel registered as spatial unit WR04 with support of the cooperation. In their arrangement, the cooperation holds one tenth of the ownership rights in the property. This is recorded as a share on the right. The rights apply to the BAUnit. The cooperation has rights on two other BAUnits – BAU05 and BAU06 – which represent bundles of four spatial units and one spatial unit, respectively. This example shows the utility of the BAUnit. If the four spatial units would be recorded independently, then administrators would have to deal with four independent records whenever changes occurred. This approach would also create unnecessary redundancy and potential for data inconsistency.

Figure 3: LADM instance diagram with a multi-party, multi-rights, multi-BAUnit, multi-SpatialUnit configuration.

Thinking in terms of a database

Having a visual way to analyse how data in a land information system is organized in various scenarios is very useful for design purposes, but does not convey any information about how the data is actually stored. A record of a particular piece of information must identify the information uniquely and contain fields that hold values for its attributes. As an example, the record of a Party instance must hold its unique ID, with attributes such as name, age and address.

A simple database might be organized according to the LADM template ‘Party-RRR-BAU-SpatialUnit’. In this case, the database would contain four tables (Figure 4) which include attributes on parties (p_id and name), rights (r_id, type, share, t_start, t_end), basic administrative units (bau_id, t_start, t_end) and spatial units (su_id, area and geometry, of which the last two are not shown in Figure 4). Each table represents a class in LADM.

A particular instance (rectangle) from the instance diagram will correspond to exactly one row in a table in the database. For example, the rows corresponding to the parties Anna P05 and Cooperation P06 are highlighted in green in the database’s Party table. Similarly, the rows in the other tables corresponding to the other instances from Figure 3 have been highlighted in their corresponding colours. Separating different LADM classes into separate tables means that changes can be made locally. Updating the name of a party after marriage should not involve changing a database row that contains rights information.

Figure 4: Database view of a land information system (LIS) structured around the four LADM core classes.

**Changes in the database **

On the topic of changes to the database, land administration data is subject to change as parties transfer rights, or spatial units get transformed through subdivision or amalgamation, through changes in laws and regulations, etc. To manage such changes in LADM, an important feature is the inclusion of object versioning. In concrete terms, this is realized in the database by recording a timestamp with every record. There may be multiple timestamps, such as when a record was created and when the change legally took effect. For simplicity, the Waterriver cadastral database presented here as an example includes only one timestamp for the start time and end time of the record (e.g. when a right was realized and when it became obsolete).

Figure 5 shows the introduction of a restriction on spatial unit WR17. Compared to Figures 3 and 4, several things have happened here. The old BAU05 has been replaced by BAU15 and BAU16, separating WR17 (the spatial unit on which the new restriction applies) from the other spatial units under BAU05. The new restriction, Restr05, is not associated with a particular party but is attached to BAU16. Two new ownership right records, Right20 and Right21, replace Right05.

In the database, the start time (t_start) of each new record equals the end time (t_end) of the records that it replaces. This type of record-keeping in the database ensures that historical records are maintained rather than being overwritten.

Figure 5: Database updates involving the mutation of records for RRRs and BAUnits without changes to other related records.

**UML classes **

Before a database can be created with properly structured and properly linked tables, it is necessary to know what sorts of data can be expected. LADM provides an out-of-the-box starting point based on its three main packages: Party, Administrative, and SpatialUnit. In UML, a package is collection of classes – model elements that represent concepts of interest in the application domain. Packages usually contain classes related to one aspect of the application. For example, the Party package contains the classes LA_Party, LA_GroupParty and LA_PartyMember (Figure 6).

A class is drawn as a rectangle with a name, usually prefixed by the package name as in Party::LA_Party, and optional sets of attributes, constraints and methods separated in different compartments. For example, the class LA_GroupParty has two attributes: groupID and type. Every attribute is suffixed with its data type. For example, the attribute type of LA_GroupParty has data type LA_GroupPartyType which is a codelist (an enumeration of predefined values). More details of the UML representation can be found in the LADM standard itself.

Figure 6: Extract from the UML representation of LADM – core classes and relationships with a focus on the Party package.

Teaching and learning about LADM

Mastering the LADM model requires studying the standard and applying the UML model in the design of land administration databases. The book LADM in the Classroom covers the most important concepts of the LADM in an accessible manner. The book comes with links to a GIS project including a dataset implementing the examples used in the book as well as slides which can used for teaching and professional illustration (see ‘Further reading’).

LADM in the Classroom simplifies course development especially for student groups that do not have prior UML knowledge. The recommended approach is to develop progressively complex exercises, starting with questions that require the student to create simple instance diagrams and adding more complex challenges as they progress through the book. By the end, the student should be able to illustrate a given scenario using an instance diagram, illustrate database updates, and identify modifications to the LADM classes to make them fit a particular land administration context.

Next steps

This article has given a broad but useable overview of LADM based on the first edition of the standard. Edition II has considerably more concepts and packages, explicitly defining concepts for all four functions of land administration, while maintaining the basic structure presented in this article, namely Party–RRR–BAUnit–SpatialUnit. A readily available application based on LADM is the Social Tenure Domain Model (STDM) software implementation. Interested readers are encouraged to explore the modelling tool in STDM to experiment with land rights modelling concepts.

Further reading

https://ladm.itc.utwente.nl/ladm_classroom

https://stdm.gltn.net/

Christiaan Lemmen, Malumbo Chipofya, Andre da Silva Mano, Abdullah Kara, Dennis Ushiña Huera, Peter van Oosterom, Eftychia Kalogianni, Eva-Maria Morscher-Unger, Javier Morales Guarin, Anthony Beck, Stephan Honer, Rohan Bennett, Paula Dijkstra and Jaap Zevenbergen (2025). LADM in the Classroom, FIG Publication, Extended Version of FIG Publication 84 (including The Land Administration Domain Model – An Overview, and LADM Edition II). International Federation of Surveyors (FIG), Copenhagen, Denmark.

https://www.fig.net/resources/publications/figpub/LADM_extended/LADM_ITC_Book_ext-2025.pdf

https://www.fig.net/resources/publications/figpub/pub84/figpub84.asp

Teaching and learning about LADM