Cadastral boundaries: benefits of complexity.
Land administration is an important aspect of public administration and private business (Dale and McLaughlin 1988). Sensible use of land is necessary for its amount cannot be increased. This makes land a good candidate for investments because it cannot be destroyed and, generally, prices increase with time. Both public administration and private ownership need data on land and systems to keep the available data up-to-date. The basic building block used for this is the land parcel as identified in the cadastre (Enemark et al. 2005). European systems typically show the parcels on maps and thus not only the parcel's size is known but also its shape, the position in relation to other parcels, and where the parcel is located within the country. These maps originally were created as paper maps, but many countries moved to using digital versions in the past decades. This digitization process includes the creation of coordinates with a specified precision that then are managed by the information system used to run the cadastre.
The coordinates add a new dimension to the parcel description. The graphical representations typically are interpreted only locally and the scale of the representation stipulates its precision. Coordinates, however, frequently are interpreted in a global way and the orientation and the exact location within the reference frame are assumed to be accurately defined. The next step--already discussed in several countries--is the three-dimensional cadastre where parcels are not represented by two-dimensional areas but by three-dimensional volumes (Stoter and van Oosterom 2006). This allows nesting volumes with different ownership, e.g., different constructions.
Each development step leads to new utilizations of the cadastral data. The costs for the development must be in accordance with the benefits received from the added utilizations. The problem when designing a cadastral system for an arbitrary country is searching the system with the best setup, given the current economic and social situation of this country. This is possible only if the relation between the extensions to the system and the additional types of utilization are clear. This paper discusses this relation with a focus on the complexity of the boundary definition.
Land is different from other physical objects such as books or cars where possession is easy to prove. Proof is more difficult for possession and (as an extension) ownership of land against third parties (Bogaerts and Zevenbergen 2001). Cadastral systems solve this dilemma by creating a connection between the land and the persons (Twaroch and Muggenhuber 1997, van Oosterom et al. 2006).
The cadastre consists of several elements (compare, for example, Jeyanandan and Williamson 1990):
* a piece of land (a parcel) in the real world,
* an unambiguous identifier for each parcel,
* a description of the spatial extent of the parcel (i.e., the boundary), and
* attributes for the parcels.
The piece of land itself is seemingly the most important element. However, in some cases, "virtual" pieces of land are introduced to model specific situations. Parcels must fulfill (at least) one condition: They must not overlap. Otherwise, a piece of land may have different identifiers, which could lead to ambiguous ownership situations. If the system is managed in two dimensions only, it is not possible to model situations where ownership is divided horizontally (for example, where the basement, ground floor, and first floor of a building have different owners). Such a situation could be modeled by parcels attached to points or lines--they then have no area and thus are not "pieces" of land.
Identifiers are necessary to address specific parcels. The identifier must be unique to avoid ambiguities in the spatial reference. Data is connected to parcels by specifying the identifier of the parcel. This connection is unique only if the identifier itself is unique. Ambiguous identifiers would lead to situations where parcels (and their data) cannot be separated from each other. Additional data describes specific aspects of the parcel. Some attributes describe geometric aspects of the parcel, for example, the size or perimeter of the parcel. Other attributes--such as the land use--are connected to activities based on the parcel or the legal status, e.g., the ownership situation.
Attributes typically result from a process. This may be either the process of observing a physical property or a social process resulting in a stipulation of a property value. Observations may be registered directly (e.g., the land use is determined by observation and the result then recorded) or indirectly (e.g., coordinates are measured with GPS receivers and then the area of the parcel is computed from the coordinates). In both cases, gross errors and random deviations are possible. This topic is discussed in the spatial data community (e.g., Guptill and Morrison 1995, Devillers and Jeansoulin 2006). Social processes result in social facts. They are attributes describing the social reality (Searle 1995). Social facts do not contain random deviations and typically are designed to prevent fraud (compare, for example, Navratil et al. 2005). An area of groundwater protection, for example, may have an uncertain outline, but the fact of protection itself is still unquestionable. Thus, some attributes have a higher reliability than do others.
Errors in attributes from social processes can arise only in the case of human error during processing of the result. Processing frequently is performed by governmental agencies. Governments typically take full responsibility for mistakes by their employees. In this case, the government absorbs the risk of erroneous values for these kinds of attributes (Bedard 1987). The data then can be assumed correct by the citizens, although the data may be incorrect. Any harm resulting from incorrect data will be compensated by the government. A typical case is the protection of good faith in a parcel purchase: The name of the owner in the land register may be misspelled and somebody who is not the owner but has the seemingly correct name sells the parcel. The buyer is in good faith and will be protected. On the other hand, the rights of the rightful owner also have to be protected. The government can solve this situation by granting the right of ownership to one person and providing financial compensation to the other person.
Some attributes in a cadastral system have characteristics of both types of processes. Boundaries emerge from the definition processes because the landowners define where the boundary is. The documentation of the boundary, on the other hand, and the reestablishment from documents is based on observations. The boundary between two parcels may, for example, be in the middle of a river. The definition is clear but the position in the real world must be determined by observations and may even change with time.
A frequent question in land administration is "Who owns this parcel?" There are two different approaches to answer this question: In a title-registration system, the answer is "The person registered as the owner." In a deed-registration system, the legality of the documents must be checked and a title search is necessary (Onsrud 1989). With both systems, the documents have to be checked for correctness and the major difference is the time when this is done (Frank 1996). Thus, in the following, this difference is ignored.
DEFINING THE SPATIAL COMPONENT
The spatial component of the parcel consists of the location and the spatial extent. The location determines where the parcel is situated. This usually is based on a national reference frame. The spatial extent describes the shape and size of the parcel. This may be accomplished using a precise boundary survey, but other methods can be used as well (van der Molen 2001). The description should include neighborhood relations or allow extracting them. The starting point is the simplest possible description of the spatial component and, stepwise, the description is precisiated. The description becomes more complex with each step, i.e., the personnel needs more training than in the previous description. A list of the possible use of the precisiated data shows the added benefit.
THE SIMPLEST TYPE OF SPATIAL DEFINITION
The specification of location requires a single point only. Nowadays, GPS as a standalone system provides an easy-to-use technical means to determine a set of coordinates and, thus, the location of such a point. The benefits of these coordinates are limited. They provide a point where other data can be attached. However, because there are no data on the extent of the parcel, relating the data set to other geographic knowledge is at least difficult or impossible. It is, for example, not possible to definitely answer questions such as the following:
* Has the parcel access to the river?
* Do two parcels share a common piece of boundary?
Statistical estimates for the parcel size can be determined if each parcel is registered as a point. An estimate for the parcel size can be derived from the point density within a specified area. The variability of the parcel sizes in the area determines the quality of the estimates.
Even this primitive spatial definition can be used for land administration. Each parcel has a spatial reference, which can be used for identifying land objects. This allows registering attributes, e.g., land rights. The missing spatial extent prevents the computation of land taxes and market value. Thus, a single set of coordinates is not sufficient for tasks such as mortgaging.
An obvious extension is adding the size of the parcel. The size can be determined in different ways but always requires a boundary. Even a rough estimate of the parcel size can be obtained only if there is at least an approximate definition of the boundary. The determination of the size then can be based on measurements, coordinates, or a scaled graphical representation (see, for example, Navratil and Feucht 2009).
The size of the parcel can be stored as an attribute to the coordinates. This allows for simple checks on data integrity. Assume that the size of a specific administrative area is known and a collection of parcels forms this unit, i.e., each parcel is either completely within or outside the extent of the administrative area. Then the sum of the parcel sizes should--within the limits of uncertainty propagation--match the size of the administrative unit. A mismatch may have different causes:
* Missing areas: Some areas may not be covered by parcels because they were either not registered or the registration is not necessary (e.g., for land owned by the community). In this case, the sum will be smaller than the size of the administrative unit.
* Overlapping areas: Owners of neighboring parcels may have contradicting opinions about the position of the boundary. This leads to overlapping parcels and overestimation of the parcel area.
* Systematic falsification of the area values: Some landowners may find it suitable to falsify the size of their parcels. Smaller parcels may lead to lower land tax and bigger parcels to higher governmental aid or increased prices in case of sales.
Apart from this integrity check, the parcel size is useful to compute:
* Land tax: A major source of income for government is tax revenue, which includes land tax. Land tax may be based on different parameters such as productivity or intended use, but knowing the size of the parcel is inevitable because owners of bigger parcels should pay more land tax than the owners of small parcels. Thus, the tax authority is a typical user of the parcel size.
* Parcel value: The value of a parcel is based on a variety of factors, including the geographical position, existing improvements such as buildings or supply lines, and the shape of the parcel. These factors determine the value of a square meter of land and the parcel size then acts as a multiplier. The value of a parcel is important in a variety of cases:
* Sale: The price usually is based on the market value of the parcel. Although there may be reductions or surcharges, the market value typically is the starting point for determining the price.
* Inheritance: In many jurisdictions, taxes have to be paid for inherited property. The taxes generally are based on the value of the heritage.
* Mortgage: Credit institutes loaning money need an alternative way to get back the money in case the debtor cannot pay back the loan. In this case, the creditor auctions off the parcel and the revenues are used to fulfill the obligations. Therefore, when loaning the money, the credit institute needs an estimate of the market value of the parcel to determine a credit limit.
TEXTUAL DESCRIPTION OF THE BOUNDARY
Up to this point, the boundary is not defined. Although a boundary is necessary to assess the parcel size, the boundary is neither defined in detail nor documented. Thus, when assessing the size of the neighboring parcels, different boundary definitions may be used and this may go unnoticed. The obvious extension is to document the boundaries. The following text is a short extract from the definition of the municipality Bad Gleichenberg (a spa, then called Curort Gleichenberg) in Austria as written in the 19th century:
The boundary of the municipality Curort Gleichenberg starts at the northern side of the road leading to Bairisch Kblldorf where the road enters the municipality Bairisch Kblldorf. The exact starting point of the boundary is a boundary stone 8.5 m east of the south-eastern end of the inn of the wine-grower Anton Hblzel sen., which represents the intersection point between the municipalities Bairisch Kblldof, Gleichenberg and Curort Gleichenberg.
Starting from this point the northern side of the road forms the boundary with the municipality Gleichenberg to the point where the roads intersects with the "Eichenwaldweg" . . . (Zabel et al. 1876, 1-2, translation by Navratil)
Although this example is rather old, similar systems still are in use, e.g., in Brazil (Mueller 2008).
The text usually refers to landmarks, which, in this context, are objects that mark a site or location and are used as points of reference (Nichols 2001). Landmarks often are used to describe routes and these landmarks must have salient features to be easily recognized (Raubal and Winter 2002). This recognition must be possible even after years when using landmarks for boundary descriptions. Typical examples for such landmarks are buildings, roads and road intersections, rivers, and sometimes even prominent trees. However, even the best landmarks may disappear after some time. The "inn of the wine-grower" in the previous example still may exist as a building, but it is possible that it is not an inn anymore, and it is a certainty that the owner changed since the creation of the description.
The advantage of textual boundary descriptions is that laypeople can create and check them. Finding landmarks in a familiar surrounding usually is not a problem as is the comparison of the description with the owner's belief about the position of the boundary. In addition, it can be easily used by courts because the description can be treated like any other text document.
The textual description also allows checking for overlaps or gaps between neighboring parcels. The previous description specifies that the boundary is formed by "the northern side of the road." The description of the neighboring area--in this case, the municipality of Gleichenberg--must use the same description. If the other description uses a different definition, e.g., the southern side of the road, then the road is either part of both communities or belongs to neither.
Adaptation of the description quality to the actual requirements is possible. Increased quality requirements lead to more detailed descriptions. Adding dimensions for segments or offsets from landmarks can provide information that can be checked and restored. These descriptions then can be used to create at least sketch maps from the boundary descriptions (Mueller 2008).
The improved boundary definition can be used to settle boundary disputes. An unambiguous boundary description can be used to reconstruct the original boundary as long as the landmarks used in the description exist and have not been relocated. Such relocation can be either a willful act by one of the landowners or part of the changing topology of the earth. The first case usually is handled in the courts because the relocation must be detected, an eventual loss of land compensated, the description updated, and--in case of an unlawful relocation--the originator punished. There also may be lawful relocations, e.g., in the previous case, an annex to the inn could be lawful and still cause a problem for the description if it affects the southeastern end of the building. The case of changing topology includes problems such as moving soil or changing riverbeds. Soil may move if the inclination of the topology is large enough and the soil layers have only a weak vertical connection. The movement may be slow, but even a few centimeters per year add to significant amounts during the time frame given by land administration. The movement usually affects landmarks, too, and thus changes the absolute position of the described boundary. Moving soil usually affects larger areas and not single landmarks. Thus, either whole parcels will move or at least larger parts of their boundaries and the boundary description often will still be applicable even in case of dispute. This usability makes boundary descriptions a valuable tool for both landowners and courts.
Boundary descriptions are not only used in case of dispute. They also serve as a confirmation for undisputed boundaries. Even if there are no disputes about the boundary, the exact position of the boundary may be unknown. This knowledge is necessary when creating a fence or placing a building at the boundary. The boundaries of inherited land especially often are not precisely known. In such cases, a textual description may inspire trust and may even prevent possible boundary disputes.
The costs are limited. All documentation is performed in textual form. Simple measurements such as the distance between the boundary and a landmark can be taken by laypeople if the distance is short. The costs thus are based on the time it takes to define and document the boundary and the involved persons typically are the landowners and an objective observer who guarantees that the definition and documentation process was performed correctly.
GRAPHICAL REPRESENTATION OF THE BOUNDARY
The next step is to collect graphical representations of the boundary. The result is either a scaled image of each parcel or a map showing all parcels within a specific area (e.g., a whole country).
The second type is more complicated because it needs an appropriate map projection even for small countries such as Austria. The discussion starts with the graphical representation of single parcels.
Unlike the textual description, the graphical representation cannot be easily produced by laypeople. Deliberate measurements are necessary to allow the reproduction of the parcel geometry. This requires two kinds of knowledge:
* knowledge about measuring and
* knowledge about geometric reconstruction.
Taking measurements is simple in regular environments, e.g., within buildings. A distance simply can be taken using a tape measure. The problems in the field are manifold, but the major issues are that distances are much longer and the terrain usually is not flat. Larger distances require either better equipment than just tape measures or sophisticated methods to avoid sources of error, for example, a tape measure that sags in the middle. Better equipment may not be at hand and may require training. Training also is necessary for more sophisticated measurement methods. The problem with the terrain is that usually horizontal distance measurements are necessary to reconstruct the boundary. This is possible for laypeople in flat terrain, but slopes may lead to deviations from the correct distance of up to three percent of the observed distance even in moderately steep terrain (Navratil and Hackl 2008). Thus, at least basic training is necessary to take the measurements with appropriate accuracy independent of terrain and vegetation.
Landowners benefit from a graphical representation of their parcels. The graphical representation can be used as a basis for mapping the contents of the parcel. It simplifies the planning of the land use for the landowner because the graphical representation provides a starting point for the planning procedure. This is especially true if dimensions such as the width of a parcel are documented in the representation as it was done traditionally in Israel (Fradkin and Doytsher 2002).
The public administration will only benefit if the graphical representations of all parcels are collected and integrated in a set of maps. These maps then can serve as a basis for spatial planning for the country or parts of it. To avoid unnecessary distortion, a suitable map projection must be selected. This is, in general, not necessary for single parcels because they are too small to cause significant (i.e., perceptible when using the map) distortions. The distortions for larger areas such as countries, however, will grow too much. Examples for suitable systems are universal transversal Mercator (UTM), Gauss-Kruger, or even an arrangement of plane coordinate systems. The map projection then is used to collect the graphical representations of the parcels.
Simple tests can be performed if every piece of land within the country must be covered by parcels. The parcels then must not overlap or have gaps between them. This is easy to check while creating the maps. Only in the transition areas between different coordinate systems (e.g., at the boundary between two stripes of a UTM projection) the check is more difficult because the testing of neighboring parcels in different systems requires a reprojection of one of them. This reprojection is influenced by observation errors and thus is imprecise. This may lead to identity problems. Therefore, the number of coordinate systems should be minimized.
The coordinate system needs a definition and a representation. The representation typically is provided by a set of reference points with known coordinates. The creation of the set causes additional costs. The set is necessary for both the initial creation of the graphical representation and the maintenance of the system. However, because the reference points usually are represented by stone monuments in the field, which rarely are destroyed by accident or influences of the weather, the maintenance costs for the reference points are low.
The benefits of such a set of maps are manifold. The resulting maps will cover the whole country and provide large-scale maps that may otherwise not exist. Regional planning, for example, can use the maps for strategic planning of transportation and nature preservation. The maps also will show if land-consolidation efforts are necessary. However, the maps are only beneficial for processes that require overview over large areas. The benefits of such a mapping effort for finding the boundary between two parcels are small because the mapping only guarantees that the graphical representations of the two parcels coincide.
The maps also may be available in digital form, either as raster data sets or in vector format. The advantage of the raster format is that it implicitly contains scale information. Graphical boundary representations are produced in a specific scale by using adequate observations. This determines the quality of the result (Frank 2009). A mapping scale of 1:1000, for example, results in a definition accuracy of at best ten centimeters. A scan of the map produces a raster data set where the color of the pixels depends on the color of the map. The boundary lines will cause such a coloring and the width of the line and the scanning resolution determine the number of pixels necessary to represent the line. Scanning with a higher resolution results in a data set where the line is represented by more pixels. This directly connects the digital data set to the quality of the original source. Vector data sets tend to lose this connection because the lines in CAD systems are infinitesimally thin and zooming creates the illusion of arbitrarily high quality.
Digitally available vector data sets can be beneficial because they simplify the use of the data, e.g., via the Internet. The data then can be included in various systems and used as a base map or as a spatial reference. Planning of future development, for example, requires such a basic data set.
REPRESENTATION OF THE BOUNDARY BY COORDINATES
While in the section titled "Graphical Representation of the Boundary," the boundary is defined by drawing a line on a map, the definition here is based on coordinates. This allows a mathematical description of the boundary, e.g., neighboring points of the boundary are connected by straight-line segments and the resulting figure constitutes the boundary of the parcel. Such a definition has an impact on the possible quality of the boundary definition. While in the case of a graphical representation, quality was determined by the obtainable mapping precision and thus determined by the mapping scale, the required coordinate accuracy can be stipulated arbitrarily and is limited only by the technical ability to determine stable coordinates and the available budget.
This may not be mixed with digital versions of graphical representations. Digital versions of graphical representations define boundaries graphically and only change the storage medium. In the coordinate-based approach, the boundaries are defined mathematically and these results then are stored in digital form. However, this is only an improvement if the added quality is used in the administrative and legal procedures. A coordinate-based approach is useless if only evidence found in the real world (e.g., boundary stones, fences, walls, etc.) is legally valid to determine parcel boundaries. In this case, the determination of coordinates would be useless because the coordinates are no improvement over a digital version of the graphical boundary definition.
The investments for creating a coordinate-based representation of boundaries are much higher than that for a graphical representation. In the case of graphical representation, parcels can be combined for small areas and these areas later merged. This may be done based on a stable implementation of a national reference system, but this is not compulsory. Other approaches are possible, e.g., updating based on neighborhood relations. The mathematical representation, however, does require a stable implementation of the reference system to define the boundary points within this system. Using Global Navigation Satellite Systems (GNSS) such as GPS as a reference system may be tempting but
1. effects of plate tectonics must be considered and
2. what should be done if selective availability or a similar measure of quality reduction is turned on?
The standard strategy to eliminate the movement of the earth is a twofold solution. In a first step, a set of fixed points is defined and then the positions of boundary points are defined relative to these fixed points. A GNSS-based solution thus requires a network of reference stations. This eliminates the problem of plate tectonics and provides the precision necessary for boundary surveys. However, the creation and maintenance of such a network causes significant costs. Several of the Austrian power suppliers maintain their own network of reference stations. Energie AG estimates costs of 30,000[euro] to 35,000.- for the basic setup and annual maintenance costs of 1,500 [euro].- per reference station (Draxler 2010). This does not include the costs for the data transfer of the creation or the rent of the required buildings. The density of the network of reference stations determines the quality of the coordinate determination. The official Austrian system consists of approximately 70 stations to cover the national territory of 80,000 square kilometers. These numbers provide rough estimates only for the costs of such a network: 30 [euro].- per square kilometer for the basic setup and 1.5[euro] per year for the maintenance. Not included are, for example, costs for buildings, data transfer, replacement of old equipment, and the required computer center. In addition, the figures are Austrian estimates and may not be correct for other countries because of different salaries, transportation costs, disaster protection, etc.
It is also necessary to use better equipment in the measurement process. GNSS do not work everywhere because GNSS need at least four visible satellites. In all places where this condition is not met, terrestrial surveying equipment such as total stations must be used. The operation of such equipment again requires training, increasing the costs of data capture. The same is valid for the analysis of the observations where consistency checks have to be performed to guarantee the quality of the result. In general, the use of the equipment needed for coordinate-based boundary descriptions requires more training because the equipment itself is more complex and the data evaluation is based on mathematics. The equipment may require knowledge that is not available and must be built during the training (e.g., understanding automatic data processing or operating a computer).
The added benefit of a coordinate-based boundary definition is the possibility to increase the accuracy. The actual accuracy depends on the processes and the equipment used, but it can be much higher than the accuracy of the graphical representation. This can be used to secure the rights of the landowners. However, legal relevance of these coordinates must be defined. There are two possibilities:
1. The coordinates, though having higher precision, are treated like verbal or graphical descriptions. The court can use this document like any other document within the judgment process, i.e., the court may ignore it if it contradicts all other sources of information or if the real world significantly changed.
2. The coordinates are defined as fixed. The boundary described by fixed coordinates is undisputable and any desired change requires a change in the coordinate description.
The first system is easier to implement because errors in the definition process can be easily corrected (not necessarily by a court). Typically, natural features take priority over these coordinate-based descriptions and thus changes in reality or errors in the data provide no problems in the reconstruction procedure (Zevenbergen 2002, 68). The second system has an advantage in case of a boundary dispute because there is little room for arguments (only within the measurement precision), but a more thorough definition process is necessary. The new Austrian cadastral system, for example, is based on the second system (Kollenprat 2003). The points defining the boundary can always be reconstructed. The boundary is represented by these points and the problem of a gradual shift of boundaries discussed in the last section is solved. While the graphical representation adapts to the new situation, the fixed coordinates protect the parcel's shape and position. Spatial planning also benefits from the added quality of the data because the planners have reliable data available in digital form.
THREE-DIMENSIONAL OBJECT REGISTRATION
In the past decade, several publications addressed the problem of three-dimensional cadastral registration (e.g., Lemmen and Oosterom 2003, Stoter and van Oosterom 2006). Scarcely available space for new constructions in modern city centers led to overlapping and interlocked constructions. The goal was an increased efficiency of the utilization of land. Registration of such interlocked rights in traditional two-dimensional cadastral systems poses a new problem: The footprints of these rights into the two-dimensional system overlap and this typically is prohibited. The solution is the construction of three-dimensional objects (Stoter and Salzmann 2003; Stoter and van Oosterom 2006, 3; Navratil and Hackl 2007; Aydin 2008).
Three-dimensional cadastral systems raise a number of new questions. The topics include conceptual discussion (Stoter et al. 2004), geometric modeling issues (Coors 2003, Tse and Gold 2003), topologic considerations (Billen and Zlatanova 2003), legal issues (Onsrud 2003), and implementation issues (Benhamu and Doytsher 2003, Aydin et al. 2004, Hassan et al. 2008). There are several prototypical systems for three-dimensional cadastral systems. Several countries, including Turkey, have stated that they strive for the introduction of a three-dimensional system. These systems should solve the unclear registration issues within the cities.
Apart from the possibility to model otherwise ambiguous situations, three-dimensional cadastral models have no obvious benefits yet. City planners may use the additional three-dimensional information and integrate them in their planning. However, they are more interested in physical rather than in legal objects and thus currently prefer using three-dimensional city models (e.g., Benner et al. 2009). New approaches to develop integrated tools use two-dimensional data only (e.g., Pereslegin 2010) or ignore cadastral data at all (e.g., Czerkauer-Yamu and Frankhauser 2010). Architects may be encouraged to include available space to combine different types of usage (compare Stoter and van Oosterom 2006, 37-41). However, these benefits are not granted because three-dimensional city models already exist, are used, and may be sufficient for the needs of architects and city planners. Significant additional costs for acquiring all data necessary for a three-dimensional registration, however, can be taken for granted.
DISCUSSION AND CONCLUSIONS
The complexity of a boundary definition can be increased in several steps. Each of these steps demands more knowledge from the persons providing the boundary definitions and requires more and more expensive equipment. On the other hand, the definitions also become more useful because they can serve additional purposes. More and more users can exploit the data if the complexity increases. Table 1 summarizes this relation. It is evident that a coordinate point alone is not useful. Just adding the area of the parcel as an attribute is already useful for landowners and the tax authority. Landowners benefit even more from boundary definitions in textual, graphical, or mathematical form. The different level of trust between these solutions is ignored in the table. The tax authority, on the other hand, only needs a value for the parcel size and some attributes not related to the boundary. Courts must settle boundary disputes and need a boundary definition to do this. A coordinate-based solution may simplify the task for the courts if the coordinates are defined as indisputable evidence. Finally, spatial planning is based on maps and, thus, at least graphical boundary representations are necessary.
The relation between the complexity of the definition and the benefits for different user groups can help developing cadastral systems. A cadastral system should provide support for space-related tasks. However, these tasks may change over time because cadastral systems are evolving concepts (Ting and Williamson 1999). Different countries have different priorities concerning public administration. Some countries may struggle with fair taxation and concentrate on solving this problem, while others may be implementing spatial planning. Thus, it is not suitable to select a cadastral solution from one country and implement it in another country. The costs of creating and maintaining the system must match the benefits to society. Therefore, implementing a coordinate-based solution is not suitable if the problem is fair taxation of land. Table 1 can provide a first impression, which type of boundary definition is suitable in a specific situation. Similar tables for other aspects of land-administration systems would help decision makers develop the land-administration system that best fits the situation in their countries.
A discussion of the exact costs of each system is difficult. There are costs for the creation and maintenance of the infrastructure, costs of training personnel, and costs of the equipment needed for the boundary definition. These costs will vary between different countries. The reasons are differences in the general education of the population, the accessibility of regions, and the availability of basic resources. Costs also may arise from special situations such as continuous landslides caused, e.g., by plate tectonics. Coordinate-based systems will need special treatment of these situations, while textual descriptions can include this problem in the text. It is necessary, however, that the costs of maintaining the system are compensated by its benefits.
The basic idea for this paper emerged from discussions with Reinfried Mansberger, Gerhard Muggenhuber, and Christoph Twaroch at the Austrian Federal Office for Metrology and Surveying (Bundesamt fur Eich- und Vermessungswesen, BEV). Reinfried Mansberger also commented on a draft version of the paper. Their contributions are gratefully acknowledged.
Aydin, C. C. 2008. Usage of underground space for 3d cadastre purposes and related problems in Turkey. Sensors 8(11):6,972-83.
Aydin, C. C., O. Demir, et al. 2004. Third dimension (3d) in cadastre and its integration with 3d GIS in Turkey. FIG Working Week, Athens, Greece, FIG.
Bedard, Y. 1987. Uncertainties in land information systems databases. Auto-Carto 8, Baltimore, MA, ASPRS and ACSM.
Benhamu, M., and Y. Doytsher. 2003. Toward a spatial 3d cadastre in Israel. Computers, Environment and Urban Systems 27(4): 359-74.
Benner, J., T. Eichhorn, A. Geiger, K.-H. Hafele, and K.-U. Krause. 2009. Public participation and urban planning supported by OGC Web services. In Schrenk, M., V. V. Popovich, D. Engelke, and P. Elisei, Eds. International Conference on Urban Planning and Spatial Development in the Information Society (REAL CORP 2009), Sitges, Spain, April 2009, 431-38.
Billen, R., and S. Zlatanova. 2003. 3d spatial relationships model: A useful concept for 3d cadastre? Computers, Environment and Urban Systems 27(4): 411-25.
Bogaerts, T., and J. Zevenbergen. 2001. Cadastral systems--alternatives. Computers, Environment and Urban Systems 25(4-5): 325-37.
Czerkauer-Yamu, C., and P. Frankhauser. 2010. A multi-scale (multi-fractal) approach for a systemic planning strategy from a regional to an architectural scale. In Schrenk, M., V. V. Popovich, and P. Zeile, Eds. International Conference on Urban Planning and Spatial Development in the Information Society (REAL CORP 2010), Vienna, Austria, May 2010, 17-26.
Coors, V. 2003. 3d-GIS in network environments. Computers, Environment and Urban Systems 27(4): 345-57.
Dale, P. F., and J. D. McLaughlin. 1988. Land information management--An introduction with special reference to cadastral problems in third world countries. Oxford: Oxford University Press.
Devillers, R., and R. Jeansoulin, Eds. 2006. Fundamentals of spatial data quality. London: ISTE.
Draxler, K. 2010. E-mail communication.
Enemark, S., I. P. Williamson, et. al. 2005. Building modern land administration systems in developed economies. Spatial Science 50(2): 51-68.
Fradkin, K., and Y. Doytsher. 2002. Establishing an urban digital cadastre: Analytical reconstruction of parcel boundaries. Computers, Environment and Urban Systems 26(5): 447-63.
Frank, A. U. 2009. Scale is introduced in spatial datasets by observation. In Devillers, R., and H. Goodchild, Eds. Spatial data quality. Boca Raton: CRC Press, 17-29.
Frank, A. U. 1996. An object-oriented, formal approach to the design of cadastral systems. In Kraak, M. J., and M. Molenar, Eds. 7th International Symposium on Spatial Data Handling, SDH '96, Delft, The Netherlands, August 1996, 5A.19-5A.36.
Guptill, S. C., and J. L. Morrison, Eds. 1995. Elements of spatial data quality. Oxford: Elsevier.
Hassan, M. I., M. H. Ahmad-Nasruddin, et al. 2008. An integrated 3d cadastre--Malaysia as an example. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences 37(B4): 121-26.
Jeyanandan, D., and I. P. Williamson. 1990. A cadastral model for developing countries. In Proceedings of the National Conference on Cadastral Reform, Melbourne, Australia.
Kollenprat, D. 2003. Grundsteuerkataster--Grenzkataster. Gemeinde-Info 6.
Lemmen, C., and P. v. Oosterom. 2003. 3d cadastres (Editorial). Computers, Environment and Urban Systems 27(4): 337-43.
Mueller, M. 2008. Transformations of cadastral descriptions with incomplete information into maps. Transactions in GIS 12(1): 83-101.
Navratil, G., and R. Feucht. 2009. An example for a comprehensive quality description--The area in the Austrian cadastre. In Devillers, R., and H. Goodchild, Eds. Spatial data quality. Boca Raton: CRC Press, 197-209.
Navratil, G., and M. Hackl. 2008. Genauigkeit der von Laien durchgefuhrten horizontalen Seitenmessung. VGI (Vermessung und Geoinformation) 96(1): 27-36.
Navratil, G., and M. Hackl. 2007. 3d-kataster. In Schrenk, M., V. V. Popovich, and J. Benedikt, Eds. 12th International Conference on Urban Planning and Spatial Development in the Information Society (CORP 2007), Vienna, Austria, May 2007, 621-28.
Navratil, G., F. Twaroch, and A. U. Frank. 2005. Complexity vs. security in the Austrian land register. In Schrenk, M., Ed. 10th International Conference on Urban Planning and Spatial Development in the Information Society (CORP 2005), Vienna, Austria, February 2005, 161-66.
Nichols, W. R., Ed. 2001. Random House Webster's college dictionary. New York: Random House.
Onsrud, H. 2003. Making a cadastre law for 3d properties in Norway. Computers, Environment and Urban Systems 27(4): 375-82.
Onsrud, H. J. 1989. The land tenure system of the United States. Zeitschrift des Bundes der offentlich bestellten Vermessungsingenieure.
Pereslegin, A. 2010. The city planning cadastre system of the city of Moscow as a tool for sustainable urban development. In Schrenk, M., V. V. Popovich, and P. Zeile, Eds. International Conference on Urban Planning and Spatial Development in the Information Society (REAL CORP 2010), Vienna, Austria, May 2010, 1,315-16.
Raubal, M., and S. Winter. 2002. Enriching wayfinding instructions with local landmarks. In Egenhofer, M. J., and D. M. Mark, Eds. Geographic information science. Berlin: Springer, 243-59.
Searle, J. R. 1995. The construction of social reality. New York: The Free Press.
Stoter, J., and M. Salzmann. 2003. Towards a 3d cadastre: Where do cadastral needs and technical possibilities meet? Computers, Environment and Urban Systems 27(4): 395-410.
Stoter, J., and P. van Oosterom. 2006. 3d cadastre in an international context. Boca Raton: Taylor and Francis.
Stoter, J., P. van Oosterom, H. D. Ploeger, and H. J. G. L. Aalders. 2004. Conceptual 3d cadastral model applied in several countries. In Proceedings of the FIG Working Week 2004, Athens, Greece.
Ting, L., and I. P. Williamson. 1999. Cadastral trends: A synthesis. The Australian Surveyor 4(1): 46-54.
Tse, R. O. C., and C. M. Gold. 2003. A proposed connectivity-based model for a 3-d cadastre. Computers, Environment and Urban Systems 27(4): 427-45.
Twaroch, C., and G. Muggenhuber. 1997. Evolution of land registration and cadastre--Case study: Austria. In Proceedings of the Joint European Conference on Geographical Information.
van der Molen, P. 2001. The importance of the institutional context for sound cadastral information management for sustainable land policy. In Proceedings of the International Conference on Spatial Information for Sustainable Development, Nairobi, Kenya.
van Oosterom, P., C. Lemmen, et al. 2006. The core cadastral domain model. Computers, Environment and Urban Systems 30(5): 627-60.
Zabel, A., G. Hoflinger, et al. 1876. Grenzbeschreibung der Gemeinde Curort Gleichenberg.
Zevenbergen, J. 2002. Systems of land registration. Ph.D., Technical University, Delfts, Netherlands.
About the Author
Gerhard Navratil is a senior researcher at the Vienna University of Technology Institute for Geoinformation and Cartography. He is working on questions of land management with a focus on data quality. Since 2007, he has been a lecturer at the University of Applied Science Technikum Wien, where he is also a member of the curricula development team for Intelligent Transportation Systems. He is also a member of the Austrian Society for Surveying and Geoinformation (OVG).
Institute for Geoinformation and Cartography
Vienna University of Technology
A-1040 Vienna, Austria
Table 1. Complexity of the boundary definition and suitability for different user groups land owner tax authority Coordinate point ? -- Coordinate point + size + + Textual boundary description ++ + Graphical boundary representation ++ + Coordinate-based definition of the ++ + boundary courts spatial planning Coordinate point -- -- Coordinate point + size -- -- Textual boundary description + -- Graphical boundary representation + + Coordinate-based definition of the ++ + Boundary
|Printer friendly Cite/link Email Feedback|
|Date:||Jan 1, 2011|
|Previous Article:||West Nile virus in the greater Chicago area: a geographic examination of human illness and risk from 2002 to 2006.|
|Next Article:||Geospatial analysis of tree root damage to sidewalks in southeastern Idaho.|