MODELING AND IMPLEMENTATION OF GEOGRAPHIC DATABASE APPLIED TO URBAN REGULATION

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1 ISSN , p MODELING AND IMPLEMENTATION OF GEOGRAPHIC DATABASE APPLIED TO URBAN REGULATION ALESSANDRO OTT REINHARDT 1 DENISE BANDEIRA DA SILVA 2 MAURÍCIO ROBERTO VERONEZ 1 1 Vale do Rio dos Sinos University - UNISINOS Graduate Program in Geology, São Leopoldo - RS Remote Sensing and Digital Cartography Laboratory {ott, veronez}@unisinos.br 2 Vale do Rio dos Sinos University UNISINOS Department of Information Systems, São Leopoldo RS {bandeira}@unisinos.br RESUMO - Os avanços nas tecnologias de Geoprocessamento (GPS, Sensoriamento Remoto, Cartografia Digital e SIG) mostram que Estados e municípios podem e devem atualizar seus sistemas, pois o gerenciamento urbano tende a ser, ano após ano, cada vez mais complexo, e o número de documentos necessários irá crescer consideravelmente. Este artigo propõe a modelagem de um Banco de Dados Geográficos (BDG), permitindo a identificação clara das entidades geográficas e dos parâmetros necessários para implementação do BDG, estruturação do SIG e desenvolvimento do Sistema Cadastral Fiscal. Nesse trabalho é apresentado um conjunto de modelos conceituais de dados para aplicações geográficas, onde o OMT-G (Object Modeling Technique for Geographic Applications) mostrou ser o mais adequado. Após a modelagem, é proposto um conjunto de sistemas para construção do BDG aplicado à Regulação Urbana. Estas etapas são importantes para um sistema complexo que precisa reunir informações precisas para identificação, fiscalização e licenciamento de atividades, imóveis e edificações. ABSTRACT - The advances in geoprocessing technologies (GPS, Remote Sensing, Digital Cartography, GIS) show that states and districts can and need to update their systems, because urban management tends to be more complex year after year and the number of necessary documents will increase considerably. This paper proposes a geographic database modeling that allows to clearly identify the geographic entities and all parameters for geographic database implementation, GIS arrangement and Fiscal Cadastral System development. For modeling, is presented a set of conceptual data models for geographic applications, where the OMT-G (Object Modeling Technique for Geographic Applications) shows to be more adequate. After the modeling, is proposed a set of systems to construct the geographic database applied to urban regulation. These stages are important for a complex system that needs to combine accuracy information to recognition, control and authorizing activities, land properties and buildings. 1 INTRODUCTION Nowadays, in Brazil, the majority of levies are still being realized in a declaratory form once the public sector does not have adequate information to confront the declarant s veracity. The public sector needs to make a detailed mapping of all territory, because with location, address and the real function of each realty, they have a mirror of occupational reality in the urban space (ERBA et al., 2005). One of the oldest types of tax levying is the property tax and very often cadastral systems start as a fiscal cadastre due to the necessity of taxing. Nobody can hide a property, so land and buildings are easy objects for taxing (BOGAERTS; ZEVENBERGEN, 2001). The GIS benefits must be combined with the specific necessities of local government planners. The determination of if and how GIS is used, however, will depends on resources, team, data availability, hardware and software (MOUDON; HUBNER, 2000). Before implementation, is important to model the geographic database because the abstraction of concepts and entities from real world is an important stage of information systems development (CASANOVA et al., 2005). This paper proposes the use of a conceptual data model for geographic applications that allows the implementation of a geographic database. All data stored in the database will be managed through an integrated way by a GIS and a Fiscal Cadastral System, both of them applied to the urban regulation.

2 This paper is organised as follows: Sections 2 and 3 present some characteristics and concepts of Cadastral Systems and Geographic Information Systems, respectively. In Section 4 some of the main characteristics of conceptual data model for geographic applications are described, the OMT-G model in special. Section 5 shows a geographic database applied to urban regulation, proposed by the authors. Finally, section 6 presents the conclusion. 2 CADASTRAL SYSTEMS Cadastral systems differ from one country to another. That explains the absence of a standard cadastral system (KAUFMANN; STEUDLER, 2002). Usually, cadastre is an updated and parcel-based Land Information System (LIS) containing a record of interests in land (e.g. rights, restrictions and responsibilities). LIS may be established for fiscal purposes (e.g. valuation and equitable taxation), legal purposes (conveyancing), to assist in the management of land and land use (e.g. for planning), and enables sustainable development and environmental protection (WILLIAMSON; TING, 2001 apud UN-FIG, 1996). Cadastral systems are established mainly to serve legal and fiscal purposes. But they can also be used to facilitate management, base mapping, value rating, land use planning and environmental impact evaluation (KAUFMANN; STEUDLER, 2001). Information technology advances and more specialized spatial information technologies have dictated and influenced many changes in the development of land administration and cadastral systems, such as spatial databases, high resolution satellite imagery, web mapping, GPS millimetre precision and geographic data interchange (WILLIAMSON and TING, 2001). When a GIS is used to manage cadastral data, it is usually named LIS (ERBA et al., 2005). 3 GEOGRAPHIC INFORMATION SYSTEMS GIS can be defined as a powerful set of tools for collection, storing, retrieving at will, transforming and displaying spatial data from the real world for a particular set of purposes (BURROUGH, 1986 apud CÂMARA et al., 2001). According to Casanova et al. (2005), a GIS receives this designation because it handles geographic data on computers. It is different from a conventional information system because it is capable to store descriptive data and also the geometry from distinct types of geographic data. So for each parcel from the urban cadastre, the GIS stores descriptive information from holder and land values, and stores geometric information with the coordinates of parcel boundary. The main characteristics from GIS are: - Inserting and integrating spatial and conventional information from different sources (census, urban and rural cadastre, satellite imagery, vector data, surveying). - Offering mechanisms that allow the combination of a great number of information, through handling and analysing algorithms, as well as consulting, recovering and visualising geographic database content. A Database Management System (DBMS) is constituted by a set of data (database) associated with a set of programs to access these data. GIS is a geographic database because it is a spatial database able to store geographic information (SILBERCHATZ et al., 1999). Due to the complexity involved in GIS applications, to project a geographic database has been one of the greatest challenges of public and private organizations (LISBOA FILHO; IOCHPE, 1999). 4 CONCEPTUAL MODELING Construct a conceptual schema to model the reality is a fundamental part of information systems development process. The choice of a modeling technique needs to be adequate to the real world objects that will be modelled. In a geographic database, the object oriented modeling allows the use of conventional classes and georeferenced classes. For georeferenced classes, it is necessary to incorporate the geometry and topology to its spatial objects, being needed to choose an appropriate representation for each one of them. (DAVIS JR.; LAENDER, 2000). Data models can vary according to the abstraction levels they provide (BORGES et al., 2001; CASANOVA et al., 2005). For geographic applications, four levels of abstraction can be considered (Figure 1): - Real world level it contains the real geographic phenomena to be represented (e.g. rivers, buildings, geology). - Conceptual representation level it defines classes that will be created in the database to represent geographic entities (e.g. river class, parcel class). - Presentation level it offers tools which allow the specification of the different visual aspects that geographic entities can assume through its use in applications (e.g. river blue colour line, culvert orange colour point). - Implementation level it defines standards, storages mechanisms, and data structure functions to physically implement each representation, as defined at the conceptual representation level, and each required presentation, as defined at the presentation level (e.g. relational database, quadtree structure). Figure 1 Levels of abstraction in geographic applications (CASANOVA et al., 2005). Spatial databases reflect two different views of reality on field view the reality is modelled by variables

3 that have a continuous distribution in space (e.g. region, segment, raster) and on object view the reality is represented by individual entities, well defined and identifiable (e.g. point, line, polygon, area) (GOODCHILD, 1992). Classification of objects in object view is more flexible and is the best view for cadastral systems where each object has a set of associated attributes which serve to differentiate it from other objects. 4.1 Conceptual data model for geographic applications Several conceptual data models for geographic applications have been proposed in the last two decades, like: GeoOOA (Geographic Object-Oriented Analysis), GISER (Geographic Information Systems Entity Relational Model), OMT-G (Object Modeling Technique for Geographic Applications) and GMOD (Geographic Data Model) (LISBOA FILHO; IOCHPE, 1999; BORGES et al., 2001). temporal aspects, but this restriction does not obstruct its use to model a geographic database. Moreover, studies to incorporate temporal extensions are already being made. 4.2 OMT-G model OMT-G model has its primitives based on Unified Modeling Language (UML) and introduces geographic primitives with the objective to increase the semantic representation capacity of its models, reducing the distance between the real world objects that will be modelled and the usual representation model. OMT-G provides primitives to model the geometry and topology of geographic data, providing support for whole-part topologic structures, network structures, multiple representation and spatial relationship. In the previous subsection just OMT-G differentiates spatial relationships from simple associations and includes spatial integrity rules, primitives to represent multiple views, primitives to dynamic modeling and primitives to presentation modeling (BORGES et al., 2001). Figure 2 Geo-object schema block polygon (BORGES et al., 2001). Figure 2 shows clearly the simplicity of models GeoOOA and OMT-G that through the use of pictograms (small graphic symbols) can significantly simplify the modeling complexity. Figure 4 Graphic notation for basic classes (BORGES et al., 2001). Figure 5 Pictograms for georeferenced classes (BORGES et al., 2001). Figure 3 Network structure street network (BORGES et al., 2001). Figure 3 presents a comparison between OMT-G and GeoOOA, where to represent a street network, it is clear that OMT-G has a high level of abstraction and easy understanding, besides having a close proximity to UML standard representation. A problem that OMT-G shows is its impossibility to model geographic information with Figure 6 Relationships (BORGES et al., 2001).

4 Figure 7 Examples of spatial generalization (BORGES et al., 2001). and spatial characteristics, as well as its social, economical and environmental dimensions. The geographic database was modeled on software Microsoft Visio 2003, that has an extension to construct OMT-G models developed by the authors of the model (OMT-G Visio stencil). All information used in modeling was based on the United Nations programme for development Annex 3, that proposes a minimum set of necessary information to computerise the municipal cadastre; on municipal laws No. 5,047 and No. 5,676 of the city of São Leopoldo that dispose about the municipal tributary code; and on information collected with the Technical Cadastre, department of Municipal Secretary of Planning of São Leopoldo (SEPLAN). The model presented in Figure 9 comprehends all the information necessary to calculate the Urban Built and Territory Tax (IPTU), not including other taxes determined by the municipal tributary code. Each new element inserted in the model will result in more sets of information and, in some cases, the integration with another systems will be necessary. Figure 8 Examples of aggregation (BORGES et al., 2001). Figures 4 to 8 make a general summary of OMT- G s main characteristics. Figure 4 presents the differences between conventional classes and georeferenced classes. Figure 5 shows the pictograms used by georeferenced classes to represent geographic entities. Figure 6 exposes the main class relationships supported. Figure 7 presents the four types of generalisation (disjoint mutually exclusive; partial does not comprehend all possibilities; overlapping can be one or both; total comprehends all possibilities). Finally, Figure 9 presents the forms of aggregation representation for the different types of classes. 5 PROPOSED GEOGRAPHIC DATABASE MODEL TO URBAN REGULATION Nowadays, many cities in the State of Rio Grande do Sul do not have an organised and proper LIS for their territories. This lack of a consolidated LIS enables the modeling of an unprecedented geographic database applied to urban regulation. The urban regulation issue deals with data relative to recognition, control and authorising activities, land properties and buildings (OLIVEIRA; OLIVEIRA, 2005). Some case studies presented by (MOUDON; HUBNER, 2000), emphasise the use of PBGIS (Parcelbased Geographic Information System) to monitor land supply, where parcel is the minor geographic unit that can be managed and controlled by a person or organisation. The great quantity of information related with the parcel object allows managers to analyse in great detail location Figure 9 OMT-G model for geographic database applied to urban regulation. In Commission 7 from the International Federation of Surveyors (FIG), it was established the Cadastre 2014 that introduces a new vision of cadastre, for which the following goals can be pointed out: to show the legal situation of all territory, to store all data (maps, images and attributes) in the same database, to use digital data and information systems, to consolidate the connection between public an private sectors, and cost recovery (KAUFMANN; STEUDLER, 2001).

5 Cadastre 2014 proposes a new vision for cadastral systems based on characteristics adopted in different countries around the world. According to this vision it is appropriate that all systems involved on the cadastre use the same database, avoiding data duplication and backup fragmentation. With the model in hands, it is clearly possible to identify the geographic entities, with its geometric (location, shape and extension), descriptive (characteristics related to the entities) and topologic attributes (relationships between entities). Therefore, it is feasible to create tables into the database, structure the GIS and develop the Fiscal Cadastral System. To implement the proposed model a MySQL relational database, a SPRING GIS and a Fiscal Cadastral System developed in Borland Delphi are used. The structure of this implementation can be viewed on Figure 10, where the user interacts with the software through a computer interface. Figure 9 Implemented Structure. MySQL is a free relational database used in many places worldwide, due to its very fast and consistent performance, high security and easy usability. The MySQL software has a robust SQL (Structured Query Language) database server, which is essential nowadays for information systems and database softwares (SUEHRING, 2002). SPRING is a free GIS developed by the National Institute of Spatial Research (INPE) and other partners. It provides an interactive environment to visualize, manipulate and edit images and geographic data. Its database architecture is dual, where alphanumeric data is stored in database and spatial data is stored in a folder on the hard disk (CÂMARA et al., 1996b). OMT-G model and SPRING GIS use the concept proposed by (GOODCHILD, 1992), representing the reality as geo-field (field view) and geo-object (object view). This compatibility grants a correct migration of the conceptual model to GIS. The Fiscal Cadastral System was developed in Borland Delphi because it is a strong software for application development and has MySQL compatible components. It is important to underline the fiscal purpose, because it is a start point for urban regulation and it is much easier than the legal purpose. GIS and cadastral system constitute together a LIS, but it is necessary to have them separated using the same database, because actually there aren t standard GIS that offer: easy data input, input restrictions, report creation, historic storage and complex calculation. 6 CONCLUSIONS GIS has been used well enough by municipal, regional and national administrations as a tool for decision making support, mainly used on environmental and urban planning (CÂMARA et al., 1996a). Despite of the several existing models for conceptual modeling of geographic data, this stage is, many times, ignored on GIS applications. According to Goodchild (1992), the choice of a data model is decisive on spatial data handling, because ultimately it affects the views which the database presents to the user, and which the user judges against empirical truth. Another important aspect to be considered is accuracy of the data and which coordinate system will be used. It is important to observe that the quality of a GIS is directly related to the accuracy of inserted data and the coordinate system adopted. This paper presented a study about geographic data models, geographic databases, GIS and cadastral systems, that together offer the main structure to recognition, control and authorise activities, land properties and buildings. The cadastre must be continuously benchmarked, having well-defined objectives, clear strategies and monitored indicators. So, all results must be measured to gain new input and cadastre improvements. (KAUFMANN; STEUDLER, 2002). ACKNOWLEDGEMENTS This study was supported by the Remote Sensing and Digital Cartography Laboratory at Unisinos University. It is part of a graduation final paper for the information systems degree from this University. REFERENCES BOGAERTS, T.; ZEVENBERGEN, J. Cadastral Systems Alternatives. Computers, Environment and Urban Systems. V. 25, p , BORGES, K. A. V.; DAVIS JR., C. A.; LAENDER, A.H.F. OMT-G: An Object-Oriented Data Model for Geographic Applications. GeoInformatica, V. 5, p , CÂMARA, G. et al. Anatomia de Sistemas de Informação Geográfica. Campinas: UNICAMP, 1996a. 197p. CÂMARA, G. et al. Spring: Integrating remote sensing and GIS by object-oriented data modelling. Computers & Graphics, V. 20, p , 1996b. CÂMARA, G. et al. Introdução a Ciência da

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