WEB MAP SERVER AS DSS TOOL FOR TERRITORIAL PLANNING OF THE AIRPORTS SURROUNDING AREAS

Maurici Ruiz Pérez 1 2 <maurici.ruiz@uib.es> Joana M. Seguí Pons 3 <joana.segui-pons@uib.es>

Jerònia Ramon Molinas 2 3<jeronia.ramon@uib.es>, Juana E. Martí Penas 2 <jemp55@hotmail.com>

M.Rosa Martínez Reynés 3 <mrmartinez@syacsl.com>

(1) IMEDEA (2) Servicio de Sistemas de Información Geográfica y Teledetección (SSIGT) (3) Departamento Ciencias de la Tierra Edifici Guillem Colom Casasnovas, Universitat de les Illes Balears (UIB). Cra. de Valldemossa, km 7.5 07122 Palma (Mallorca, Spain). This paper will present the results of the AEROSIG project �Design of an Expert system for the Management of Airport Areas�, financed by Ministerio de Fomento. (Aids to investigation 2003, Spain). The main aim is the development of a methodological tool to improve the territorial planning and management process of the airport surrounding areas. The works have consisted on the development of an Expert System prototype tested on a 5 km area influence from the airport of Palma (Mallorca, Spain). From a territorial database, a deep space analysis has been developed in relation to the behavior of the different variables, and their distribution patterns as well as their relationships. Consequently, multicriteria models have been implemented in order to create a set of decision rules which will allow to identify the suitable uses and adapt to its territorial characteristics. The user interface has been implemented in a Web-based technology, which has a Cartographic Server built over the Internet GIS software: ArcIMS (ESRI) that fulfills the standards OpenGIS Consortium and facilitates the user the remote access to the system and the cartographic information. It can be used at http://www.aerosig.org.

1. Introduccion

There are many experiences in the development of automated systems to assess territorial planning activities. The process begins with problem definitions and description, which involves various forms of analysis (modelling, predictions�) and evaluation of alternative solutions to the problem. The geographic information system (GIS) is being adapted to the spatial decisions in the planning process. Usually, these systems include precise functionalities to solve planning problems in a precise environment. In other cases, general models adapted to any territorial planning problem are proposed.

The AeroSIG project is included in the first group of systems and its specialization is focused on the planning of areas affected by important environmental impacts derived by the airport activities. The main objective of AeroSIG is to offer a computer tool based on a spatial decision support system oriented to land use assignment in a strong territorial pressure like the airport surrounding areas in order to facilitate the planning process and the territorial integration of airport infrastructures.

On the other hand, the use of Internet has become the GIS and the DSS more comprehensive tool . Using the web as a platform has several advantages as once finished, it can be used everywhere. This service makes relevant data more accessible to the public, planners and politicians. Additionally, it does not require extensive computing equipment or data collections.

The key added values of AeroSIG system can be found in its geodatabase design (which includes a set of territorial variables of impact diagnostic and land aptitude) and also in its capacity of generating reports of the airport territorial integration.

Airports, according to the Spanish, law are considered as transport infrastructures with public interest, and its planning and design is developed by the Ministerio de Fomento in Madrid. Consequently, Regional and Local governments must adapt their planning to the prescription done by the Central Government. Each airport has a complete and unique Master Plan (Plan Director) which defines all the technical and urban characteristics of the airport and its environment.

The airport surrounding areas show an absence of specific territorial planning instruments. These areas display remarkable evidences of strong environmental impacts with both positive and negative effects derived from the airport activities. All kind of land uses (residential, industrial,�) can be found in these areas although there sometimes seems to be an absence of urban planning. The most important negative environmental impacts are: airship noise, air pollution, land occupation by accessorial infrastructures, night luminosity and traffic congestion. The correct planning of these areas would avoid many negative impacts and at the same time, it would give solutions to the existent ones. It should be appropiate to adapt the use of those areas to their territorial suitability, for instance, the industrial sevices (the development of new services or industries related to the air transport) and consequently avoid the residetial use for a possible future expansion.

2. Geographic Information System (GIS) and Decision Support System (DSS)

The display and manipulation of spatial information on a computer is usually achieved using GIS. It provides a mechanism to store, manage, analyse and visualize geo-related data. GIS is applied to many areas of knowledge and every day the number of new applications is increasing. There are many applications of GIS to planning or management of airport infrastructures. For instance, the Erie International Airport (Erie, Pennsylvania) has developed a GIS system to detect the residential areas affected by an expansion of the Airport area. Another example is the GIS created by the Syracuse Hancock International Airport (Syracuse, New York) used to analyse the environmental impacts generated by the airport. In Spain, there aren�t many examples of GIS applications for airport planning or management. In the last years AENA (Aeropuertos Españoles y Navegación Aérea) company, responsible for the planning and management of Spanish airports, has started to build GIS systems with management purposes for the main airports. These GIS applications only include the airport infrastructure areas, leaving the surrounding areas out of treatment.

The functionalities of GIS as DSS tool highly increase when the system incorporates instruments of artificial intelligence as Expert Systems (ES). Besides the functionalities of GIS to solve spatial problems, it allows to integrate a basis of knowledge in the form of rules and together with the interaction with decision-makers, it will give answer to the users improving their decision-making. An Expert System tries to emulate the way in which the experts solve specific problems based on a Basis of Knowledge. The ES can be used by the non-expert users to solve similar problems in different ways (HOLMBERG; 1996) It is in this field that one perceives its great utility in the field of territorial planning.

The components that form the Expert Systems are: the basis of knowledge, the inference engine and user's interface (ENGEL & JONES, 1992). Keeping in mind this structure, the information stored in the system as �Basis of Knowledge� is the source of information on which the whole system will be developed.

GIS can be used to assist spatial decision problems by eliminating areas that do not meet certain requirements through Boolean queries and weighting the remaining areas based on certain criteria or factor. The integration of the GIS technology and Artificial Intelligence decreases the time and the cost of the planners in organizing the information when taking decisions. The Geodatabase that sustains the GIS system is usually the source of knowledge of the ES based on GIS technology.

The integration of Web-based GIS and traditional planning tools provide a means to address issues about equity and access in planning (CAVER and PECKHAM, 1999). In terms of Web GIS the challenge is to support dynamic maps and interactive customized maps. In this way, Internet Map Server (IMS) applications allow GIS database custodians to easily make their spatial data accessible through a web browser interface to end-user. In this way, non- expert users, particularly user-friendly interfaces, can easily access to geo-information in order to: integrate a multi-source data, to seek advice as if it was a GIS, to test working hypothesis and finally to represent the cartographic results.

3. Study area

Airport infrastructures have an area of wide territorial influence and it hardly ever coincides with the administrative delimitations of the territory. In most of the cases the study of the territorial effects of the airports is usually restricted to the areas of sound impact of the airships. It is usually concentric elliptic areas that are generated from the landing hints. The meteorological conditions, the amplifications of the infrastructures, or the plan of the controllers' route continuously alter the itineraries of the airplanes in the take off and landing routes. For this reason, the territorial delimitation of the areas of sound influence is not constant.

From the territorial point of view, the sound impact, in spite of their evident environmental importance, doesn't usually condition the uses of the territory in the adjacent areas of the airport infrastructures in a direct way. In fact, the occupation of the territory in many occasions seems to be developed as an independent variable of the vicinity to the airport. Even the residential uses, in some cases, seem to ignore the sound pressure to which they are subjected. The speculation of the territory in big cities is affected by the sound impact of the airports. However, it doesn't usually mean

a discrimination of the residential use, but a reduction of the price of the land. This is the reason why many of these areas finally become more or less degraded zones.

The territorial delimitation of economic influence of airports is still more complex due to the fact that these infrastructures act as powerful centres of economic activity with implications in all the economic sectors. So, the geographical extension of the economic effects of the airport extends at regional and national level.

For this reason it is not possible to establish the area of territorial influence of an airport in a standardized way. Any formula or singular mathematical function that defines it doesn't exist, and the dividing line is not clear, although the relationship among the distance to the infrastructure and perceived impacts is evident

The AEROSIG project has been developed studying the areas under the influence of Son Sant Joan airport in Palma (Mallorca, Spain). From the economic point of view, the influence of the airport of Palma extends to the whole island of Mallorca. The economic model is centred in the tourist industry and its geographical condition as an island makes it extraordinarily dependent on its airport (flow of tourists and goods).

AeroSIG only seeks to analyse the problems of the most immediate environment, the territory that suffers the physical and social impacts of the airport activity more directly. To define the area of immediate influence, a circumference of 5 km of radio has been drawn around the airport. Such area is also sustained by the results obtained in previous field works and in the analysis of the territorial variables of the area. In fact, this area becomes reinforced by an identical delimitation carried out by AENA (Public enterprise of airport management) for the development of the Environmental Impact Assessment of the amplification of the airport project carried out by the Ministry of Development in the year 2003.

Figure 1. Exact map of the study area

The dimension of the area of influence proposed (5 Km.) should neither be considered as a proposal, nor as a suggestion. The objective is to have a territorial margin of extensive analysis to settle the influence area for different environmental, economic and social variables with more precision. The width of the area will depend on the threshold of impacts that is considered susceptible of being corrected by means of an specific ordination development plan of the airport surrounding area.

3. Methods and techniques

The study of the AeroSIG project, consists of a Web-based GIS framework to integrate a great amount of inputs into planning. It has required the development of the following tasks to structure and manage the airport surrounding areas planning process on the Web:

1. Interviews with the resident population and tourists. A survey, including the total population of the area, has been carried out in order to appreciate optimum results. A total of 450 interviews have been made with an estimated reliability of 99,5%. With that objective, a form was especially designed to detect the environmental impacts of the airport, the acceptability of the infrastructure by the population, and the population´s opinion in relation to the topics mentioned above. The surveys have been evaluated using the software SPSS vers. 10.

2. Geodatabase construction. The design of geodatabase has been made using the habitual techniques of programming and implementation of a specific Spatial Data Model in order to create the adequate knowledge data of the Expert System. An analysis of requirements was carried out and also the type of information to be considered was evaluated. Finally, an analysis of the different types of functionalities to be included in the system was elaborated.

3. Integrated territorial analysis. A complete territorial analysis of the surrounding areas of the airport of Palma has been conducted starting with the use of statistical techniques (basic statistical analysis, several different analysis, classification analysis, etc) as well as with the use of the analytical capacities of the GIS. A cartographic atlas of the area has been elaborated likewise. The software used in this analysis has been the ArcInfo vers. 8.3, the SPSS vers. 10.

4. Expert System. The expert system has been built starting from the generation of decision rules over the geodatabase. The goal is to facilitate the planner´s task when assigning the territory uses at the same time as guaranteeing and facilitating the collection and updating of the information. The system is structured in four development areas:

a. Generation of homogeneous areas. Starting from the base variables and using the spatial analysis procedures of cartographic overlapping, the ES generates a synthesis coverage that concentrates all the information of the Geodatabase.

b. Generation of territorial impacts. A tabulated report will be made by means of the definition of decision rules that establishes the relationships among the variables and among the different thematic categories. This report allows the detection of the main impacts of the airport over the environmental variables.

c. Generation of territorial aptitudes. Using the same procedures previously mentioned, but adding a multicriteria model of variables integration; aptitudes for diverse land uses will be defined for each homogeneous areas mentioned in point (a).

The design of the established rules of decision required the creation of a Panel of experts. This expert team provided the relationships among variables, as well as it provided information about the importance of each variable in the implementation of the multicriteria model.

The realization of the project needed the application of some computer technologies making use of the following computer programs: ArcInfo vers. 8.3, ArcIMS vers. 4.01, SPSS Vers. 11., Javascript, Microsoft VisualBasic 6.0.

5. Web Map Server. WebGIS technology has a number of characteristics that can enhance the traditional planning process. Several commercial or open source systems exist with web map server capability. The software for developing the AeroSIG application was ArcIMS v.4.01 (ESRI). Using this interactive cartographic tools, the users are able to create their own display by selecting information to be included on the map. That permits greater and better control, management and analysis of the spatial information and consequently, a major objectivity in the planner´s process of decision making. Using JavaScript, a function was created to allow the users to obtain territorial information from the ES.

4. Results and discussion

The results of the project have been of two types:

- Methodological results: spatial data model and expert system.

- Applied results. They make reference to the application of the ES at the pilot area of the airport of Palma (survey, geodatabase, territorial analysis)

Survey. One of the first territorial results of the project corresponds to the extracted conclusions of the survey analysis carried out over the resident population and tourist of the influence area of Palma airport. Among these conclusions we highlight the following ones:

1. The main environmental impacts to the population produced by the airport are: noise of airplanes, scents to fuels and traffic congestion.

2. The direct negative effects of the airport extend until a maximum distance of 3 km.

3. The population doesn't manifest a special rejection to the infrastructure in spite of its proximity.

4. The main perception of population consider the airport as the economic motor of the region and this causes a bigger acceptability.

5. The tourism doesn't seem affected by the negative effects of the airport in distances over 1 Km.

We can deduce therefore that from the point of view of residents and users of the next areas to the airport the influence area never will be greater than 5 kms. This survey could justify the adoption of a Performance Plan in a radius of influence maximum of 3 km from the airport of Palma.

Spatial Data Model. The first methodological result of the project consists of the design of a GIS spatial data model on which the ES will be built. This data model incorporates specific territorial information to give support to the tasks of planning and territorial administration of the airport environment. The information is structured in three levels:

Level 1. Basic territorial variables. They include four thematic groups: physical or abiotic environment, biotic environment, and socio-economic environment.

- Abiotic environment: The variables included in this group represent the physical environment. They are topographical, hydrological, geological and geomorphologic variables. Also, variables representing environmental impacts should be included in this group as well as the quality of the air, acoustic pollution and chemical pollution.

- Biotic environment. The variables included in this group reflect the natural vegetation and fauna ecosystems of the area.

- Socio-economic environment. This includes variables that represent the human activities developed in the area; land uses, settlements, population, road network, urbanism, etc.

-Territory background. Basically includes political boundaries.

Level 2. Variables of Impact. The impacts generated by the airport activities over the environment will be included in the data model. The ES directly generates these variables. The main variables of impact are :

- Population/buildings affected by the noise of the airships

- Population/buildings affected by the chemical pollution of the air

- Visual impact of the infrastructures by the population

- Effect on the natural spaces by the acoustic pollution

- Effect on the natural spaces by the chemical pollution of the air

Level 3. Territorial Aptitude Variables. Aptitude variables will generate the ES and include land aptitude of each homogeneous area for many uses: conservation, extensive agriculture, intensive agriculture, urbanization, industrial, recreational uses and services.

Figure 2. AeroSIG Spatial Data Model

Geodatabase.

Once designed the spatial data model of the Geodatabase, the information was included in the database by means of manual digitising or conversion tools.

Integrated territorial analysis.

Many spatial analysis tools and statistical procedures were applied over the Geodatabase in order to study the geographical pattern of each variable and to detect relationships between variables.

It is important to highlight that there is not any clear relationship among the proximity of the airport infrastructure to other variables except those that represent physical o chemical pollution of the airport (atmospheric pollution, noises, etc).

The localization of the airport, in the surrounding area of Palma city implies that its environment is subjected to diverse pressures: intense urban activity, reduction of the agrarian uses, concentration of infrastructure and services of the city (hospitals, central electric, commercial centres, etc). All these activities are more or less independent from the airport. In fact, there is not evidence of direct relationship between the airport and the urban development of its surroundings.

Evaluating the relationship among the variables of the Level 1 of the Geodatabase, by means of a multivariate analysis we find that there are three significant components that represent 90% of the total variance: the land use, the acoustic pollution and the protection of the territory.

Figure 3. Cartographic representation of territorial variables

Expert system

The system AeroSIG identifies and quantifies the areas affected by airport noises and allows evaluating the degree impact. AeroSIG helps the territorial agents to develop a rational land use plan detecting impacts and territorial aptitudes.

Figure 4. Territorial aptitudes

AeroSIG is an Internet computer application based on GIS technology and artificial intelligence tools to act as a spatial decision support system for territorial planning.

The key of the system is the translation of the results of the multicriteria analysis of impacts and aptitudes to decision rules. These decision rules are included in the geodatabase and they are used as the inference engine of the system. When a query is asked to the system the rules call to the knowledge basis, represented by the geographical data and generate an answer.

Web Map Server

The user interface has been implemented in a Web-based technology (http://www.aerosig.org). From de main web page one has access to the documentation of the project as well as a cartographic data base that illustrates the considerated variables and that can be donwloaded in PDF format. The icon �Expert System� gives access to the Web Map Server to generate a dynamic cartographic product. It has built over the Internet GIS software: ArcIMS (ESRI) that fulfills the standards OpenGIS Consortium and facilitates the user the remote access to the system and the cartographic information.

There are two kinds of users to the access of the Web Map Server: the administration that creates the geodatabase and includes all the decision rules and the other users who work directly with the system to support their decisions.

This tool incorporates the access to cartographic information, the selection through the pointer of one location generates a activity report that serves information of the characteristics of the selected area (landuse, soil, neighbourhood aspects, assessment of suitability, evaluation of environment problems,�) and proposes suitable uses and activities. The AeroSIG system allows its use in other scenarios and therefore facilitates the tasks of territorial planning and management.

Figure 5. Image of the user interface

One of the main results of the project is to recognize that it is absolutely necessary that the airport Master Plans include the surrounding areas of the airport infrastructure. The surrounding area must be studied as a unique zone and the Master Plan must propose sustainable uses on this area. The present situation of absence of planning coordination on this areas will cause a chaotic model of land uses and the negative impacts of the airport affect the quality of life of people leaving or working on this areas.

6. Acknowledgements

We want to thank the Ministerio de Fomento of the Spanish Government the financing of the project AEROSIG, the company AENA for their collaboration, and the Conselleria de Obras Públicas of the Balearic Government for the surrender of the topographical cartography.

7. References

BROW, A.W. ; PITT, M.R. Measuring the facilities management influence in delivering sustainable airport development and expansion. Facilities, 2001, nº 5-6, p. 222-232.

BUECH, R.; MARTIN, H.M.; RAUSCHER, H.M. An Application of Expert Systems for Wildlife: Identifying Forest Stand. Prescriptions for Deer. AI Applications in Natural Resource Management. 1990, vol 4, nº 1.

CAVER, S.; PECKHAM, R. Using GIS on the Internet for Planning. In: Stillwell JCH, Geertman, S. and Openshaw, S. (eds) Geographical information and planning, Springer, Berlin and New York, 1999. pp 371-390.

CENTRAL NEW YORK. REGIONAL PLANNING AND DEVELOPMENT BOARD. Hancock International Airport. Geographic Information Systems Project, [On-line]. <http://cnyrpdb.org/programs/land/gis-ha.asp>. [25 de septiembre de 2003].

ENGEL, B.A., D.D. JONES, T.L. THOMPSON Integrating Expert Systems With Traditional Computer-Based Problem Solving Techniques. An Applications in Natural Resource Management, 1992, vol. 6, nº. 2, p. 5-12.

FORO COLABORATIVO DE LOS PARTICIPANTES DEL TRANSPORTE AÉREO FAST FACTS. La industria del transporte aéreo se ha unido para presentar sus hechos y cifras. [En línea], febrero 2003, http://www.aci-europa.org/upload/fast%20facts%20Spanish%20(low%20resolution).pdf [enero 2004].

GAMIR, A.; RAMOS, D. Transporte aéreo y territorio. Barcelona: Ariel, 2002, pp.329

HOLMBERG, S.C. Problem solving and decisión support with GIS. In M. Rumor et al. (eds) op. Cit. 1996. Vol. 1, pp. 566-569..

ITS Programme (Information Society Technologies, TAP programme (Telematics Applications). [En línea], 2000, <http://www.cordis.lu/its/kal/trans-tourism/home.html>. [marzo 2001].

JAFFE, S. Airport geographic Information Systems-An Emerging Role. Airport magazine. [On-line]. American Association of Airport Executives (AAA), 2003, <http//www. Airportnet.org/depts/publications/airmags/am34981/gis.htm>. [enero 2004].

MORENO , A. ; LINDSAY, R. Modelling a single type of environmental impact from an obnoxious transport activity implementing locational analysis with GIS. Environment and Planning A, 2003, vol 35 p. 931-946.

SCHIPPER, Y.; RIETVELD, P.; NIJKAMP, P. Environmental externalities in air transport markets. Journal of Air Transport Management, 2001, vol 7, p. 169-179.

SHAW, S.L.; XIN, X. Integrate land use and transportation interaction: a temporal GIS exploratory data analysis approach. Journal of Transport Geography, 2003, vol 11, p. 103-115.

The Airport Master Plan [on-line], Erie International Airport, 2002, http://www.erieairportprojects.org/project_alt.htm. [22 de octubre de 2003].

WREEKER,R.; NIJKAMP, P.; TER WELLE, CH.A criteria decision support methodology for evaluating airport expansion plans. Transportation Research Part D, 2002, nº 7, p. 27-47.

SAATY, T.L., VARGAS, L.G. Prediction, Projection and Forecasting. Kluwer Academic Publishers, Dordrecht, 1991. 251 pp.

SAATY, T.L. The Analytic Hierarchy Process: Planning, Priority Setting, Resource Allocation, McGraw-Hill, New York, 1980.

SEGUÍ, J.M.; MARTÍNEZ M.R..; RUIZ, M.; MARTÍ, J.E. Tecnologías de la información y de la comunicación en los sistemas de transporte aéreo: AEROSIG, una propuesta de planificación y gestión de los entornos aeroportuarios. VI Coloquio Internacional de Geocrítica. Disponible en: http://www.ub.es/geocrit/c6-aerosig.htm

BARREDO CANO, J.L. Sistemas de Información Geográfica y evaluación multicriterio en la ordenación del territorio. Ra-ma Editorial. Madrid, 1996.

GÓMEZ OREA, D., Ordenación del territorio, una aproximación desde el medio físico. ITGME y Editorial Agrícola Española S.A. Madrid, 1994.

KERSCHBERG, L. Expert Database System. The Benjamin/cummings, California. 1988.