CadastreGeospatial - GISTerritorial Planning

What a geomatician should know about the LADM land management standard

It is known as LADM to the Land Administration Domain Model, which managed to become ISO 19152 from 2012.

It is not a software, but a conceptual model that outlines the relationship between people and the land; it standardizes what it seems in each country is different and specialized; it is a materialized process of something that in the 2014 Cadastre was considered as abstract. It seeks to avoid reinvention and re-implementation of the same functionalities by means of a base that is extensible and makes it easier for institutions to communicate with standardized services in an international context.

Aware that geographers and people linked to geomatics need to know how to interpret models, we do this exercise to explain the origin of this standard from that moment when it was conceptualized as CCDM.

It is interesting that the LADM in part of its simple smoke poses that the administration of the land is a concept immutable in the time, has not varied in thousands of years:

It always consisted of the relationship that exists between man and earth. No matter the culture where it is analyzed, history shows us something similar: People, such as the case of Adam and Eve, who in a common state are delegates to administer the Garden of Eden, with the right to be inside, responsibilities over what is there, and restrictions not to eat from a prohibited tree and expropriation rules in case of not following them.

That orchard is now called BAUnits, with a relationship of rights (RRR) with stakeholders, linked to people (Party) through a Source and in various forms of representation of the space entity (Spacial Units).

Ladm

The truth is that as the systems of administration of property rights advance, there are complex cases that at the level of registration were always there but waiting to model their representation are cases such as:

A couple who own a 60% - 40% relationship of an asset that constitutes an apartment 23 on the 4th floor of a building, and that also includes the right to two parking spaces in basement 1 and the right in condominium with all residents from the building to the lobby of each level and a barbecue area on the eighth floor. Legally it is easy, it is only written but let's ask ourselves how we model it in a 3D cadastre, or at least in a 2.5 D.

With the LADM it is sought that the way of modeling the concept of land rights administration in computer tools is the same. Because the business is the same, it varies to a small extent is the medium and the procedures that are very specific by country or discipline. The little custom to handle models makes it seem that the LADM is an astral wave only for computer scientists, perhaps because it is modeled in UML from classes and relationships, however, the surveyor proposed in the project is part of the responsibility. 2014 Cadastre: “Long live modelling”.

It is, therefore, a model of geospatial semantics, focused on the main functions of land administration:

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  •  Keep the Object - Sujet - Right relationship updated (P - RRR - RO)
  • And provide information on this record.

The model also seeks to facilitate the standardization of the technological pressure that constitutes, on the one hand, the offer (Internet, spatial databases, standardized models, open source licenses and GIS) and, on the other hand, a demand for services that take advantage of this technology (government electronic, sustainable development, electronic documentation and integration of public data and systems). One of the advantages of the LADM is that it can be adapted to each country, regardless of its legislation, the institutional separation of cadastre and registry, or the type of tool that will be used for automation. It suggests standard classes, and from there you can do country-specific classes but in the end the concept is compatible.

The great victory of the LADM lies in linking the academic effort through the FIG with standardization initiatives that already existed, such as the LINZ and LANDxml of Australia / New Zealand, the National Integrated Land System of the Americans (formerly FGDC), the actions Of the European Commission on Science and Technology (COST), the ISO / TC211 Committee of the OGC and especially lobbying in high-impact spaces. And it is that the difficult thing about making a standard is the imposition or reinvention of what others have already specialized.

 

A Little History

La FIG was born in 2002, it tries to appropriate this effort and lobby with recent initiatives such as the case of Inspire and the IDE concept that took hold around 2003. Thus, in short steps the LADM goes through different moments of presentation, discussion and adaptation of different versions that took the name of the city where they were presented, until they became ISO 19152 of 2012:

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  •  In April of 2002 the possibility of doing something is raised for the first time.
  • In September of 2002 is presented in the OGC the version 1 called Noordwijk, soon in Delft in the COST Workshop.
  • In March 2003 version 2 called Paris, that same year in the FIG and for this date the OGC announces the LPI
  • In September 2003 version 3 called Brno is released in Poland. For this date, the extensions of the 3D multipurpose cadastre have been added. It was also presented at the European Land Information Service EULIS.
  • In 2004 the 4 version called Bamberg, is presented in FIG events in Germany and Kenya.
  • In 2005 version 5 was called Cairo, at the FIG event in Egypt. By then, the standards that the OGC managed through Committee ISO / TC 211 have been integrated; Although this committee has published more than 50 standards of great interest in the geomatic field, the LADM takes two from here: Geometry and Topology). Also for this date it becomes Inspire's cadastral data specifications.
  • In 2006 version 6 called Moscow is presented, which is this version that we talked about in Geofumadas in the article “A standard model for cadastre“. This already includes Building RRR and the Part of parcel is explained in a separate all-purple class.

From 2006 to 2008 the effort is focused on accreditation as a standard.

  • In October of 2006 already presents the Version 1.0 although by that date was called CCDM (Core Cadastral Domain Model).

The process of making it an ISO standard, by means of different meetings of discussion, extension and specific definition of claeses; Ends in 2012 by means of Chrit Lemmen's doctoral thesis in 2012.

There is still a long way to go, several countries have already adopted the standard, although much remains to be done. After this standardization effort, a process of implementation and landing has come to reality, where links have been made with the JRC (Joint Research Center of European Commission) and UN-HABITAT (United Nations Agency for Human Settlements) to be applied in projects linked to territorial management. With this, examples have been materialized in different countries, the case of the STDM (Social Tenure Domain Model) standing out, which is considered a specialization of the LADM, the Flossola on the part of FAO and in Honduras the SIGIT prototype that now seeks to scale to SINAP.

 

Explanation of the Model

The exercise of this article is that we try to understand the origin of the LADM based on a graphic scheme. I am trying to use colors similar to the model classes, which already in the approved standard separate the legal part in yellow, the person in green, the objects in blue, the topography in pink and the topology in purple. Sure that using icons will bring us some relationship by association but I insist; we have to learn to understand models. Hovering over objects shows their meaning.

[hsmap name=”ladm”]

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The main entities.

The scheme starts from the relationship between the three main entities:

  • Stakeholder (Subject), in the norm defined as Party
  • Object of law, which in this case removes the archaic concept of cadastral parcel and takes it to territorial object. In the standard is called BAUnit, and its geometry Spatial Unit.
  • Law, relationship that links the person with the object, in the standard defined as RRR.

The model links them by means of the source (Source). This can be documentary or factual; it's just reality. The rest are possible cases:

  • Not only is there an owner, but a group of heirs, one of them with life imprisonment,
  • The plot has a flat, but it is on paper and has no georeference,
  • The subdivision has not been determined, but only the percentages of right ... one of the brothers already sold his right to four more people,
  • This portion sold has a mobile phone tower with an access server,
  • Part of the plot is affected by a protected area under special regime,
  • One of the brothers is a minor, so he is legally represented by his gay mother ...

Whether or not there is a map, whether or not it is legal, whether or not it is in accordance with the procedures, it is a reality that is there. Therefore, the LADM accepts that reality is recorded in a controlled manner, indicating the physical and legal situation.

 

The interested party (Party)

Note that here the simple "subject" is extended to the different people involved in the transactions. Thus we have:

Ladm - copy (2)

  • The individual person
  • The legal entity, as in the case of an institution or company
  • The grouping of people, such as the case of an indigenous group, an association, peasant group, etc.
  • The person or institution that certifies the right, such as the lawyer's case
  • The person or institution that certifies the mortgage, as in the case of a bank or financial institution
  • The person making the measurement document, such as the surveyor.

 

 The relationship of rights (RRR)Ladm - copy (3)

Here, in the traditional cadastre it was only a type of tenure. But the model is extended so that the different possible conditions of relationship of law and administrative burdens can be adapted:

  • Mortgage or encumbrance
  • The affectations, which can be Restrictions, Attributions and Responsibilities.
  • The tenancy relationship with the source.

 

The Object of Law

Ladm - copy (4)

Here there are different levels of classes, but everything basically starts from the object that is called the administrative unit (BAUnit). See that this is an abstraction of the object, whether or not we have a map or a document.

This is because in reality there is an object, which will gradually be documented, but the BAUnit starts from that and in the first instance there are the "non-georeferenced" scenarios:

  • The non-real object, that is, what can be removed from the plot, such as the case of a mobile home, a telephone antenna, etc.
  • An identifier of a real estate base
  • A non-georeferenced document
  • A physical address that identifies a house within a building, and this can be beyond the apartment level within a building.

Then there are the BAUnits that have a spatial identification, among these can be:

  • The unstructured parcel (part of parcel), which can be a point, a set of points and boundaries.
  • The structured plot, which can be a unit, or several in relation to a single property.

One of the advantages of adopting the LADM model is that no data is negligible, there is no good or bad cadastre, only a represented reality. Administrative units exist and can improve precision from:

  •  A base of taxpayers of a municipality that are only sworn statements stored in Excel.
  • Later they can have a coordinate, with what a dotted cadastre is a primitive but valid solution.
  • Then you can have plots, but not with high precision.

Everything closes in the spatial identification of the plot, with different levels of representation for a simple reason "in physical reality the object is only one". It is also important that not only private law is reflected, but also public law, as in the case of a protected area or spatial entities defined in different legislations as a flood area that affects the parcels.

 

Ladm - copyRepresentations of the object.

This is a series of special classes that allow defining different types of topographic representations of the same object, that is why they are linked to the source.

The important thing here is that the minimum unit of measurement is a point, which is the responsibility of the surveyor. Different conditions for 2D and 3D are detailed.

In the case of two dimensions, a point, then the boundary in arc-node relation and then the shape in closed geometry. The same exists for 3D although here is one more case that is a 3D object not composed of faces.

The linkage of the topographic representation is through the source, taking into account that there will always be a document that defines a greater precision that can not be drawn in the cadastral parcel as part of a context.

In conclusion, the LADM is a standard to be known. It is a materialization of the abstract raised in the Cadastre 2014 to which we have already arrived; although with many achievements in the technological and academic part with many challenges in the institutional and normative part.

Golgi Alvarez

Writer, researcher, specialist in Land Management Models. He has participated in the conceptualization and implementation of models such as: National Property Administration System SINAP in Honduras, Management Model of Joint Municipalities in Honduras, Integrated Cadastre-Registry Management Model in Nicaragua, Territory Administration System SAT in Colombia . Editor of the Geofumadas knowledge blog since 2007 and creator of the AulaGEO Academy that includes more than 100 courses on GIS - CAD - BIM - Digital Twins topics.

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8 Comments

  1. Does not give me the description when I mouse over the icons

  2. Hello, you can have the ppt that appears in the photo

  3. Actually, the model is adapted to the country. If a country decides that certain data will not use it ... it does not use it.
    The important thing is that the data model uses the standard for data that does apply.

  4. If it is already difficult in Peru to be able to enter the houses to obtain a pair of information data, obtaining all the information requested in the LADM is more complicated. And even more complicated to take data from the farms in Callao.

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