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GIS approach in urban geographical studies: a focus on Hungarian examples NAGYVÁRADI L. & SZEBÉNYI A. Department of Physical Geography and Geoinformatics, University of Pécs, 7624 Pécs, Ifjúság u. 6, Hungary, [email protected] Abstract. The researches and the analysis of the urban development and the active factors (environmental, social, economic and vehicular) of settlements become mostly available with the use of GIS. The rapid development of GIS methods and tools permits management, storage and analysis of the extreme large data bases. The use of GIS tools enables us to analyze spatial and temporal relationships among various datasets and to make analyses and future prognoses. The numerical analysis of the interaction between natural and social factors is only possible with GIS. The GIS analysis of various factors (land use, morphology, economical development, motorization, migration, and suburbanization) of urban development gives exact and objectives result for urban development models. Keywords: GIS routines, urban geography, research methods, theoretical formula 1. Introduction. Nowadays many social geographical researches focus on (great) cities, urban areas and agglomerations, because the quick growth of population and the high concentration of the social and environmental risk. More than half of the Earth population lives in urban areas. This tendency is valid in Hungary (65%). The rate is 82% in the US 42% in Asia and 40% in Africa. The urban population of the EU is 72.2% today but this rate will be grow up to 80% in 2030 (UN 2007). The aim of our research is to find the most effective GIS operation between the traditional and computer based methods of the urban geographical analysis, primary focused on suburbanization and settlement development. Also an aim of our study is to explore the most characteristic factors of the urbanization processes in Hungary. Our methods included collection of the traditional research methods of the urban geography, the analysis of events, to explore the characteristic features of Hungarian urbanization, and to find the contact points of the GIS and urban geography. In this paper we studied the relationship between the urban geographical research methods and the GIS, which GIS routine is the most effective. We also studied the characteristics of the data and the adaptability of those in the process of Arc GIS analysis. We analyzed the importance of the coherency of the data. 2. Developing the problem. Since 1990 the process of the suburbanization in Hungary follows the earlier urban development tendencies of the US and Western-European countries. This is the reason why Hungarian urban researches have focused on this subject [16]. The next urban geographical factors supported our hypothesis: demographical changes, built-up area development, green spaces, housing estate, road network system, motorization, migration, daily migration, landuse-changes, natural hazards. The urban geographical analyses on the basis of the factors: tendencies of urban development (suburbanization), and demographical changes; settlement evaluation, housing estate register, optimal function of the public traffic, modernization of the administration (to find the optimal local administrative units based on the connection of the neighboring settlements), the optimal spatial network system of the ambulance-stations, timescale studies about the decreasing of the driving time on overcrowded roads, flood control and protection. These are the most important urban geographic research factors studied (with GIS methods) by the Hungarian researchers in the last few years. The question is what kind of GIS routines we have to use, to get the best result to analyze urban geographical research factors, and the relationship among them? 2.1. The traditional methods of the urban geographical analysis The main goal of the researches of the urban geography is to analyze the development of the cities in different aspects. The disciple of demography is in line with urban geography. Demography researches focused on the structure and spatial situation of the population, the migration to allow for the natural surroundings, factors also [17]. The obvious research method in urban geography is the traditional statistical analyses. But usually it is necessary to supplement with questionnaire as the type of primer data collection. Another important research method is the interview, because it produces better, deeper information like the questionnaire. We can get answer not only for the questions, but the notions also. It is an important help to make a good questionnaire [1]. 2.2. GIS routines with examples from urban geographical researches in Hungary Our study verified that multiple GIS routines and functions are usable in urban geographical studies. We ranked these GIS routines and operations that included morphological analyses (relief, urban), spatial decision analysis, decision support system, distance analysis, buffer-analysis, cost surface-analysis, urban development predictability and finally the modeling. One of the most popular research territories in Hungary also, the urban land cover researches with remote sensing. The complex geometry and diverse characteristics of the objects of study in urban land cover analysis require remotely sensed data wit very high spatial and temporal resolution [8]. Segment based classification results are easier to interpret and show better overall accuracies as well. In the researches of settlement morphology the researches used both vector and raster GIS, and combined the results may be the solution to define morphologic categories for cities [11]. In another aspect is the research of the Geo-spatial distribution of

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203 the urban area using object based routines with raster model [14]. The new urban management researches help the process of the decision support system with GIS connecting for different functions by their common attributes (their location) [9]. The traditional geographical researches earlier studied the relationship between the physical and urban environment. Today to study this relationship is more effective using GIS because the huge databases (satellite images etc.) and new aspects [7]. Some research try to find the similarity between using the same GIS routine like morphological analysis of the natural landforms (slope aspect, hill shade etc.), the horizontal morphology of the settlements, and also the vertical morphology of the great cities, mainly the downtown area [11]. Nowadays the urban climatology researches using 3D surface geometry of the built-up area, with this research it is possible to calculate not only the local urban climate, but the streets ventilation, the air pollution, effects of the traffic, and the daily migration and spatial aspects of ambulance service in Hungary [13] also, to get complex result of the “living” urban environment [6], [15]. GIS-based model to monitor and predict the future (sub) urbanization processes for large agglomeration. Reclassification will then provide the list of settlement that are characterized by above-average development rate, and based on their present day growth trend steady-state growth is predicted in the future as well [10]. 2. 3 Theoretical formulas We collected the research methods of urban geography, and made a selection based on frequency. In the second phase we assigned the GIS routines what enhancing the objectivity of the results. We produced two theoretical formulas: (1) F + Gv → C (C) (C) and (2) F (F) (F) + Gv → C (C) (C) This formulas above to sign the research factors of the urban geography with symbol F (F) (F), the GIS routines with Gv, and the coherency (operative adaptation) between factors and GIS routines C (C) (C). In the first formula (1) F is a numerical value; Gv is the variable, what defines the value of the C. The three different F in the second formula (2) and C symbol sign the type of the coherency between them. Factors (F) (F) (F) built-up area development Motorization, migration, daily migration, road network system

GIS routines (Gv) Distance analysis

motorization, daily migration, road network system built-up area development

Buffer-analysis

motorization, road network system, daily migration built-up area development

Cost surface-analysis

built-up area development, green spaces, natural hazards road network system demographical changes, built-up area development housing estate natural hazards green spaces built-up area development natural hazards green spaces housing estate

Morphological analyses (DEM, 3D model)

All factors

Coherency (C) (C) (C) (operative adaptation) settlement evaluation, landuse-changes tendency of urban development (suburbanization) the optimal spatial network system of the ambulance-stations optimal function of the public traffic, timescale studies about the decreasing of the driving time tendency of urban development (suburbanization) optimal function of the public traffic, the optimal spatial network system of the ambulance-stations tendency of urban development (suburbanization) settlement evaluation landuse-changes

tendency of the demographical changes tendency of urban development landuse-changes flood control and protection housing estate register Decision support tendency of urban development system (suburbanization) landuse-changes modernization of the administration housing estate register GUDeM tendency of urban development tendency of demographical changes Table 1. Theoretical formula adaptation for the factors of the urban geography Spatial decision analysis

The table (1) shows the rank of the GIS from the simple to the multiple operations inclusive modeling. The final and highest stage of the urban geographical researches: General Urban Development Model (GUDeM)

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204 3. Conclusions The results of this paper to provide research method for the researchers to answer for the questions and solve the problems of the urban geography using traditional and GIS methods together. Our results are usable by the local and regional governmental administrations in the processes of decision-making, settlement management and the sustainable development of the cities also. The GUDeM are used regionaly to solve problems related to suburbanization, emergency services, land use, business efficiency, natural hazards, green spaces etc. References [1] E. Babbie, 1999, A társadalomtudományi kutatás gyakorlata, Balassi Kiadó, Budapest [2] T. Bugya, Sz. Á. Fábián, N. L. Görcs, I. P. Kovács, B. Radvánszky, Surface changes on a landslide affected high bluff in Dunaszekcső (Hungary), Central European Journal of Geosciences 3: (2), 2011, (pp. 119-128). [3] Sz. Czigány, E. Pirkhoffer, B. Balassa, T. Bugya, T. Bötkös, P. Gyenizse, L. Nagyváradi, D. Lóczy, I. Geresdi, Villámárvíz mint természeti veszélyforrás a Dél-Dunántúlon, Földr. Közl. 134(3),2010, (pp. 281-298). [4] Sz.Czigány, E. Pirkhoffer, I. Geresdi, Impact of extreme rainfall and soil moisture on flash flood generation, Időjárás, 2010 (pp. 79-100). [5] Sz. Á. Fábián, N. L. Görcs, I. P. Kovács, B. Radvánszky, G. Varga, Reconstruction of flash flood event in small catchment: Nagykónyi, Hungary, Zeitschrift Für Geomorphologie 53: (Suppl.2), 2009 (pp.123-138) [6] T. Gál, J. Unger, 3D városi felszíngeometriai adatbázis jellemzői és városklimatológiai alkalmazási lehetőségei Szeged példáján, Az elmélet és a gyakorlat találkozása a térinformatikában II. Debrecen, 2011 (pp.75-83). [7] P. Gyenizse, Geoinformatikai vizsgálatok Pécsett. Pécs településfejlődésére ható természeti és társadalmi hatások vizsgálata geoinformatikai módszerekkel. Geographia Pannonica Nova 7, Publikon Kiadó, Pécs, (2009) [8] L. Henits et al. Nagy felbontású távérzékelt adatok alkalmazása a városi felszínborítás vizsgálatában – lehetőségek és problémák, Az elmélet és a gyakorlat találkozása a térinformatikában II. Debrecen, 2011 (pp. 43-53) [9] G. Karig, L. Tóth, Térinformatikai alapú komplex városüzemeltetési rendszerek, Az elmélet és a gyakorlat találkozása a térinformatikában II. Debrecen, 2011 (pp.67-75). [10] L. Nagyváradi, A. Szebényi, A. Rábay, Modeling the suburbanization of the Budapest agglomeration (Hungary) with GIS methods the aspect of the sustainable development, International Proceedings of Chemical, Biological and Environmental Engineering 13, (2011) (pp. 161-167). [11] Zs. Ónodi, A településmorfológiai kutatások újszerű módszerei, Az elmélet és a gyakorlat találkozása a térinformatikában II. Debrecen, 2011 (pp. 83-91) [12] E. Pirkhoffer, Sz. Czigány, I. Geresdi, Gy. Lovász. Environmental hazards in small watersheds: flash floods - impact of soil moisture and canopy cover on flash flood generation. Riscuri şi catastrofe, Cluj-Napoca, Casa cartii de stiinta. 2009 pp. 117130. [13] G. Pirisi, A. Trócsányi, Spatial effects of the ambulance service in Hungary. Regional Statistics, Journal of the Hungarian Statistical Office, Vol. 14(51), 2011 (pp. 44-54). [14] L. Ronczyk, A városi térszerkezet vizsgálata távérzékelési módszerekkel, Az elmélet és a gyakorlat találkozása a térinformatikában II. Debrecen, 2011 (pp. 91-99). [15] J. Szűcs, Cs. Lénárt, T. Bíró, Significance of the determination of roughness length based on GIS in dispersion modelling, Földrajzi Közlemények 135, 2011 (pp. 219-227). [16] J. Timár, M. M. Váradi, The Uneven Development of Suburbanization during Transition in Hungary, European Urban and Regional Studies 8 (4), 2001 (pp. 349-360). [17] J. Tóth, Általános társadalomföldrajz. Dialóg Campus Kiadó, Budapest-Pécs (2001)

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