Spatial dyamics of coastal Cities i Greece S. Polyzos*, D. Tsiotas ad F. Papaioaou Departmet of Plaig ad Regioal Developmet, Uiversity of Thessaly, 38334 Volos, Greece Correspodig author: E-mail: spolyzos@uth.gr, Tel 24210 74446 Abstract Durig recet decades the coastal cities i Greece have experieced a rapid trasformatio; maily due to touristic developmet, urbaizatio ad icrease of their populatio. Greece (Hellas) is characterized by its high coastal cocetratio ad it is estimated that 57% of the coutry's populatio live i coastal areas. These high cocetratios o the coast suggest also a tedecy towards urba developmet sprawlig alog the coast ot ecessarily i high desities. This paper deals with urbaizatio ad the cosequet ecoomic developmet ad chage, which have characterized the spatial evolutio of the Greek (Helleic) coastal areas over the last few decades. The cocetratio of ecoomic activity i coastal areas as a result of urba growth i the coastal prefectures is aalyzed, by usig fudametal spatial ad ecoometric descriptive measures. Key words: coastal tows, Greece, urbaizatio 1. Itroductio Coastal cities have played diachroically a leadig role to the developmet of huma civilizatio, ought to their geographical characteristics, provided from the seaside locatio. Although coastal locatio ofte etailed the risk of attacks i the history [1],[2] it also provided may trasportatio (developmet of ports) [3], commodity (trade developmet) [4] ad evirometal advatages (such as mild climate ad atural beauty) [5]. Nowadays, the touristic utilizatio [4],[6] of coastal cities appears i the developmetal foregroud, revealig the sigificat amout of profitable potetials for a coutry s ecoomy. Those developmetal dyamics occurred at a time whe the sigs of a greater uiversal chage were visible, called urbaizatio [7]. This pheomeo, of abadoig the rural areas ad settlig i cities uder the prospect of better employmet opportuities [8], came ito promiece [7],[9] ad rearraged the geographic status of Greek populatio. Demographic pressures [4], the state of locomotio from a dese city to a rarer uder the terms of acquirig life quality, have also costituted a parameter i the Helleic seaside tows developmet, durig the period 1961 2001. These pressures, i cojuctio with the cosequet cotiuous eed for expasio of urba cores [10], usually took place through a city s liear projectio alog its coastal forehead [4], which redered the evolutio of coastal cities to be cosidered a multivariable spatial pheomeo. The purpose of this paper is to deal with the evolutio of the Helleic coastal cities through the demographic trasformatio held durig the recet fifty (50) years. The objectives of the research are first to model the metioed trasformatio, by usig spatial aalytic ad regioal ecoometric tools, secod to recogize the patters that compose this trasformatio ad fially to iterpret ad evaluate these patters, uder the regioal policy perspective. The preset study aspires to provide the essetial (demographic based) documetatio for the pursuit of the Helleic policies that target to regulate the coastal cities developmetal potetials ad to ispire other researchers to approach this multidimesioal topic through its supplemetary perspectives. Ideed, although the research o coastal cities dyamics presets a efficiet scietific matter [3],[5],[6],[11], so i Global as i Mediterraea scale, the aalogue Helleic research ca be cosidered sprigtime. This research s disarragemet, firstly, reiforced the authors to deal with the coastal cities dyamics ad, secodly, sets, automatically, the utility of the preset paper to be cosidered itroducig. This Proceedigs of the 3 rd Iteratioal CEMEPE & SECOTOX Coferece Skiathos, Jue 19-24, 2011, ISBN 978-960-6865-43-5 1263
paper is orgaized as follows; sectio 2 presets the study area ad the available data, sectio 3 describes the research methods used to model the spatial trasformatio, sectio 4 presets the results ad the evaluatio ad, fially, i sectio 5 coclusios are give. 2. Study Area ad Data The followig research deals with these cities of the Greek territory (terrestrial ad islad), which preset a populatio over 5.000 ihabitats (figure 1), accordig to the official cesus of 1961. The choice of the 5.000 ihabitats threshold is selected arbitrarily, but takig uder cosideratio the Act 3643/2006 [12]. Due to the Helleic coditio, 59 out of 155 cities with populatio over the defied threshold oly foud coastal, cosistig the object maifold of the research. The selectio criteria are based o Kiousopoulos [13] classificatio, uder which coastal areas ca be divided ito three (3) categories: (a) the spatial uits that have direct cotact with the sea (are littoral), (b) spatial uits that are lackig direct cotact but are adjacet to littoral (havig a easy access to the sea) ad (c) these spatial uits which are deprived of ay cotact with the sea. The preset research icludes the amout of cities of the first two categories that surpass the populatio threshold of 5.000 citizes. Hece, as urba populatio is also cosidered the semi-urba populatio (tows), ought to limited umber of the immiscibly urba areas i Greece. This cocessio is ot supposed to affect the coclusio makig process, sice Hellas does ot preset sigificat metropolita ad urba scales. Figure 1. Spatial distributio of Helleic coastal cities with populatio over 5.000 citizes. 3. Research Methods Three (3) fudametal aalytic tools derived from spatial statistics ad regioal ecoometrics are used: the weighted mea ceter (WMC) [14], the Cetral Feature (CF) [14] ad the Theil idex [15]. WMC is the average x ad y coordiate of all the features i the study area as show at relatio (1) [14], where x i, y i are the coordiates ad w i the weight of the poit i. WMC is a useful measure for trackig chages i a distributio or for comparig the distributios of differet types of features. I this study WMC will be used to compare the spatial distributios of the Helleic coastal cities appearace for the decades 1961 up to 2001. The WMC rollig (shiftig), cosistig 1264
of a five poit (step) trail (WMC 1961, WMC 1971, WMC 1981, WMC 1991, WMC 2001,) is expected to reveal the demographic trasformatio ad the potetials of the coastal cities i Greece. w x w y WMC ( X, Y ) X, Y w w i i i i i1 i1 i i1 i1 CF tool idetifies the most cetrally located feature i a poit, lie, or polygo feature class. Distaces from each feature to every other feature i the dataset are calculated (weighted) ad summed [14]. The mathematical formula of the cetral feature is related to the closeess cetrality formula [16] ad is show at relatio (2). The use of this tool is expected to disclose the most vital Helleic coastal city i terms of populatio ad cetrality. w dc CF c c c dc i 1265 i ij i1 j1, ij { 1,..., } mi i, 1,..., wi The Theil idex costitutes a statistic fuctio for iequality measuremet aalysis. The idex appertais i the etropy measures family ad has a comparative utility. The idex s mathematical formula is described by equatio (3). 1 xi xi T l (3) i1 whereas x i stads for the arithmetic value of the observatio i for the characteristic (variable) Χ (i=1,,), lx is the apieria logarithmic fuctio ad μ the mea of the observatios x i (i=1,,). Theil idex rages ito the iterval 0 Τ l [15]. Theil idex s usage is cosidered to reveal the cities that preseted the greatest variatios i their chroological evolutio. 4. Results ad Discussio Durig the study period, the Helleic urba populatio coverage chaged 29,5%, from 56,21% i 1961 to 72,79% i 2001. This fact implies, firstly, the structural chages that the Greek ecoomic model was subjected (the meawhile period) to, which suggests the coutry s traspositio from the agricultural-based ecoomy model (primary sector) to the services provisio ecoomy model (tertiary sector). Secodly, the meawhile urba growth ca be related to the pheomeo of agglomeratio that beefited the two Helleic metropolita cities, Athes ad Thessaloiki. By observig the treds i the Mediterraea level [4], a similar traspositio i the demographic status ca be observed. Urba populatio of coastal coutries preseted a amout of 50% growth durig the period 1950-2005, percetage which is higher i compariso with the correspodig Helleic, probably due to sigificat urbaizatio rates of South Mediterraea coutries ad Turkey. The growig Helleic coastal cities cover the 16,42% of the total coutry s populatio i 1961, whereas i 2001 they reach to represet approximately 2.100.000 ihabitats, with a coverage of 19,43% i total populatio. The augmetative treds appear to be strog durig the first two decades of the study period, but they dimiish from 1981 ad forward. Betwee the cities that demostrate the greatest populatio icrease i the decade 1961-71 are maily the coastal Muicipalities of Athes (38% average icrease) ad Thessaloiki (37% average icrease). Muicipalities of Kalamakio, Glyfada ad Kallithea preset i correspodece a 222%, 90% ad 51% icrease i Athes, as well Kalamaria ad Thessaloiki a 47% ad 38%, but also several other large coastal cities preset a sigificat growth (mostly prefecture capitals of the provice), such as Korithos (31%) ad Chalkis (27%) (figure 2). O the opposite side of the rakig, primarily isular cities, such as Leukimmi i (1) (2)
( Kerkyras prefecture), Messii ( Messiias prefecture) ad Polyxitos ( Lesvos prefecture), forfeited beyod 20% of their populatio dyamics. At the ext decade (1971-1981), the augmetative tred is geerally maitaied, with the city of Glyfada ( Attikis prefecture, with 19% average icrease) to preset a populatio icrease of 88%, Pylaia ( Thessaloikis prefecture, 44% average icrease) 74%, Palaio Faliro 52% ( Attikis prefecture) ad the frotier Alexadroupolis ( Evrou prefecture) 50%. Some isular cities, such as Kos (33%) ad Irakleio ( Kritis prefecture) (31%) appear also a cosiderable icrease. O the other had, the overspill is distributed i prefectures of Lesvos (with two cities losig beyod 20% of their populatio) as well as of muicipalities ( Filiatra ) of Messiias prefecture with a loss of 17% (while the average loss of Messiias coastal cities is 5%). Figure 2.Comparative pie-charts of the coastal cities populatio distributio for the period 1961-2001. Durig the decade 1981-1991 the coastal muicipalities of the Helleic greatest urba prefectures ( Attikis ad Thessaloikis ) appear to mitigate their previously itese populatio augmetative treds (correspodig average icreases 8% ad 30%), while provicial cities, which had forfeited their populatio s dyamics durig the last decades, are ow reiforced. Thus, cities of Iraklio prefecture (21% prefecture s average icrease), such as New Halicarassus (28% icrease) as well as of Messeias prefecture (5% average icrease, while the previous two decades preseted decrease), such as Filiatra (23% icrease), are foud to ehace their populatio size. Muicipalities of Attikis prefecture, such as Piraeus ad Drapetsoa were foud to decrease their populatio by approximately 7 ad 11% i correspodece. The overall dimiishig global tred of urbaizatio rate [3],[4],[7] seems to be verified also for the Helleic coastal cities state the metioed period. I the last decade (1991-2001) fially, thigs appear to complicate. O the oe side, a reiforcemet of cities i the territory of Athes (13% average icrease) becomes evidet, such as Aspropyrgos (77% icrease) ad Glyfada (27% icrease) ad, o the other side, peripheral cities are also stregtheed such as Alexadroupolis (29%) as well as several cities i Crete ad Dodecaese prefectures. The above cosideratio seems to explai the diachroic shiftig of populatio s WMC [14], which is depicted at figure 3 ad was calculated due to relatio (1). Figure 3 esures the fact that the WMC of the specific sample of cities lies close eough to the urba agglomeratio of Attikis (Athes) prefecture, despite the fact that certai muicipalities, which are deprived of direct cotact with the sea, were ot examied. Obviously the populatio weight of the rest muicipalities, as 1266
well as of the city cluster earby Athes, is capable of maitaiig this ceter close to Athes, despite also of the icreased populatio weight of Thessaloiki, which it seems resposible for ot beig the city of Piraeus the cetral feature but the city of Aspropyrgos, as show i figure 3 (right). Figure 3. (left) Spatial rollig of the weighted mea ceter (right) the cetral feature for the period 1961-2001. The shift of WMC from 1961 to 1971 is almost upright with a small deviatio towards the west, so as to coclude that maily the orther coastal cities, as well as the wester oes, have reiforced their populatio rates durig this period, to the detrimet either of mior rural tows or of the easter ad souther parts of the coutry. Ideed, the muicipality cluster of Kalamaria, Thessaloiki ad Pylaia i Thessaloikis prefecture seems to be resposible for the orther shift such as the muicipality cluster of Kalamakio ad Glyfada for the wester ( Attikis prefecture). The directio of the shift was reiforced by some cities forfeit, such as Souda ( Chaia prefecture) i the South, which decreased its populatio 10% ad Polihitos ( Lesvos prefecture), which decreased 19%. The ext decade s (1971-1981) shift does ot appear to differetiate sigificatly. The mior shift of the WMC towards the orther ad easter part of the coutry seems to result both from the populatio reiforcemet of cities with a cogeer directio, such as the coastal muicipalities of Thessaloiki, Kavala ad Alexadroupolis, ad from the populatio weakeig of coastal cities with exactly the opposite directio. For example, the cities of Amfilochia ad Messologi ( Aitolokaraias prefecture i west Hellas) lost 7% ad 12% of their populatio, such as Filiatra i wester Pelopoesus that lost 17%. The decade 1981-1991 the WMC status begis to differetiate majorly. This period is characterized by a detoatio of the Athes populatio elargemet to the eighborig regios, as well as the repletio, o the other side, of the Thessaloikis courbatio. Cosequetly, the shift of the WMC towards the souther ad slightly easter part of the coutry seems reasoable. More adjacet cities to Athes tha to Thessaloiki occupy the top positios i rakig durig that decade, as far as their populatio shift is cocered. Besides, several cities of the souther isular part of the coutry are reiforced, such as Kos (24%), Rethymo (32%), Nea Alikarassos (27%) ad Irakleio (13%). Similar coclusios are draw for the last decade (1991-2001), which is characterized by outright more itese tedecies, a fact that is idicated by the shift of the WMC i figure 3. Cities that are located i the orth-east Aegea ad Crete play a fudametal role i populatio icrease rates i cojuctio with cities of south Attikis. Fially, the applicatio of the Theil s idex is expected to reveal uder which mode (itese, described by cosiderable iequalities, or eve, described by cosistecy) the chroological evolutio shift took place i the Helleic coastal cities. Figure 4 maps the Theil idex s calculatio results. 1267
Figure 4.Spatial distributio of the coastal cities Theil idex for the period 1961-2001. Figure 4 illustrates these cities, which throughout the study period (1961-2001) preseted the most abrupt chages i their populatio. This map reveals the strog fluctuatios (positive i the majority as preseted earlier) of the city clusters of Athes ad Thessaloiki that are characterized of the most itese meawhile courbatios. These city clusters demostrated itese fluctuatios i their populatio, such as the coastal muicipalities of Aspropyrgos, Glyfada, Drapetsoa, Kalamaki ad Pereus i Attikis prefecture ad the muicipalities of Kalamaria ad Thessaloiki ad Pylaia i Thessaloikis prefecture. A secod cluster of cities of medium to otable variatios is comprised of the cities of the provice, the most sigificat of which are located i Kritis prefecture (Crete), i the islads of Souther Aegea ad the city of Alexadroupolis i the Evros prefecture. I all these areas, the populatio rates were icreased, ad oly the cities of Lesvos prefecture, i the regio of orth-easter Aegea forfeit a importat percetage of their populatio. Fially, a third cluster of cities is formed i the so called developmetal axis S of the coutry, where cities of Patra, Corith, Chalkis ad Katerii costitute cities with a relatively abrupt chage of their populatio sizes. The tow of Nafpaktos could perhaps be icluded i this cluster primarily due to the proximity with the city of Patra. 5. Coclusios The preset paper dealt with the populatio trasformatio of Helleic coastal cities, held durig the last 50 years. Coastal cities over 5.000 citizes were studied, by usig the fudametal spatial ad ecoometric descriptive measures of the weighted mea ceter, the cetral feature ad the Theil idex. These idexes calculatios mapped ad aalyzed, uder the populatio perspective. The geeral coclusio that was formed is that after 50 years of demographic chages i the Greek coastal cities, the WMC appears to be oly slightly easter differetiated. This half-ceturial rollig deotes that the coastal populatio trasformatio suggested a reversed U shaped trail. From the phase of the itese urbaizatio (durig the decades of 60 s ad 70 s, where the ceters of the Metropolita cities of Athes ad Thessaloiki grow) ad the phase of suburbaizatio (i the decade of 1980 s, where the suburba zoes of the two metropolita Helleic cities expaded) the coastal status moved ito a ew balace, described by the stregtheig of maily the Attikis prefecture s cities-satellites (which suggests the pheomeo of couter-urbaizatio) ad secodly the south-easter isular regios of Hellas. 1268
6. Refereces [1] Birie, P., 1987. Piracy: Past, preset ad future, Marie Policy, 7, pp.163-183. [2] Aderso, J., 1995. Piracy ad World History: A Ecoomic Perspective o Maritime Predatio, Joural of World History, 6(2), pp.175-199. [3] Li, H., 2003. Maagemet of coastal mega-cities a ew challege i the 21st cetury, Marie Policy, 27, pp.333 337. [4] Cori, B., 1999. Spatial Dyamics of Mediterraea Coastal Regios, Joural of Coastal Coservatio, 5(2), pp.105-112. [5] Yeug, Y., 2001. Coastal mega-cities i Asia: trasformatio, sustaiability ad maagemet, Ocea & Coastal Maagemet, 44, pp.319 333. [6] Miller, M., Auyog, J., 1991. Coastal zoe tourism, Marie Policy, 3, pp.75-99. [7] Roberts, B., 1989. Urbaizatio, Migratio, ad Developmet, Sociological Forum, 4 (4), pp.665-691. [8] Log, H., Zou, J., Liu, Y., 2009. Differetiatio of rural developmet drive by idustrializatio ad urbaizatio i easter coastal Chia, Habitat Iteratioal, 33, pp.454 462. [9] Ο Sulliva, A., 2003. Urba Ecoomics, 5th ed., Bosto, USA, McGraw-Hill Publicatios. [10] Beriatos, E., Papageorgiou, M., 2010. Towards Sustaiable Urbaizatio ad Spatial Plaig of the Coastal Zoe i Greece ad the Mediterraea Basi, preseted at the 46 th ISOCARP Cogress, Nairobi, Keya, 19-23 September 2010 [11] Sheg Ha, S., Ya, Z., 1999. Chias Coastal Cities: Developmet, Plaig ad Challeges, Habitat Itl 23(2), pp.217-229. [12] Act 3463/2006, Ratificatio of the Code of Muicipalities ad Commuities, Issue A, serial umber 114 [13] Kiousopoulos, I., 2008. Methodological approach of coastal areas cocerig typology ad spatial idicators, i the cotext of itegrated maagemet ad evirometal assessmet, Joural of Coastal Coservatio, 12, pp.19-25. [14] Mitchell, A., 2005. The ESRI Guide to GIS Aalysis, Volume 2. ESRI Press. [15] Polyzos, S., 2011. Regioal Developmet, Athes, Greece, Kritiki Publicatios. [16] Wag, F., Atipova, A., ad Porta, S., 2011. Street cetrality ad lad use itesity i Bato Rouge, Louisiaa, Joural of Trasport Geography, 19, pp.285-293. 1269