THE ACCESSIBILITY IN NETWORK. CASE STUDY: ATU GĂGĂUZIA Vitalie Mamot Faculty of Geography, State Tiraspol University Rezumat: Mişcarea populaţiei este unul din factorii determinativi ai vieţii societăţii. Reducerea consumului de timp şi distanţe inutile au fost şi sunt una din tendinţele principale în dezvoltarea societăţii. Accesibilitatea populaţiei este determinată în mare parte de căile de acces către servicii sau către alte obiective ce asigură buna vieţuire a oamenilor (accesibilitatea către serviciile medicale, pompieri, la justiţie, poliţie, pieţe de desfacere, instituţii de învăţământ etc.). Se analizează reţeaua de transport rutier din Unitatea Teritorial Autonomă Găgăuzia, care include măsurătorile de distanţe; formarea rutelor intre localităţile unităţii administrative şi centrul administrativ, ca prestator a majorităţii serviciilor, formarea zonelor de accesibilitate (prin isochrone); determinarea densităţii reţelei rutiere pe comune etc. Key words: road network, accessibility, access zones, network density, isochrones. Introduction This study comes to complete the investigation started for the assessment and the measurement of transport networks in administrative districts of the Republic of Moldova. It is tried to identify the GIS processes for measuring the capacity and structure of networks of the same kind as the content and theme. The networks of any type can be caracterized by size, location, structure, connectivity, pressure on its structural elements etc. In the south of the country there are located two territorial-administrative units - Cahul and Autonomous Territorial Unit of Gagauzia (ATUG). The road network of Cahul Unit was the subject of a research in wich several network indicators were analyzed as time and distances in the network, the level of accessibility from and to the administrative center etc. (Mamot, 2008). The Autonomous Territorial Unit of Gagauzia (ATUG) is located in the south-east of Moldova, holding an area of over 1 832 sq km. This unit includes 33 localities with a population of 155 646 inhabitants. ATUG includes three administrative districts – Comrat, Ciadar-Lunga and Vulcanesti. The form and content of the transport network is determined by the geographical position of the administrative unit. Gagauzia represebts a structure of five territorial components, disconnected from each other. This division is largely 11 due to the ethnic structure of the component localities. In most localities, only a few exceptions, the majority population is represented by the Gagauz. The main road arteries mostly repeat the directions on wich the ATUG territories stretch. The most important roads are: Road M-3 that connects the southern country (Giurgiulesti customs) with Chisinau, but less used on the Cimislia-Chisinau section for technical reasons. This road partly passes the ATUG’s territory. It plays the role of transport collector from the dispersed territories of Gagauzia; Road R-36 – links Cazaclia locality with Cioc-Maidan commune through eastern extremity; Road R-37 – collects the transport flow on the south-east – north- west directionfrom Comrat and Ciadar-Lunga districts; Road R-35 unites Cioc- Maidan commune with Comrat town. The extension and structure of ATUG determine different levels of accessibility by the population of the services like justice, firefighters, medical emergency service etc., usually offered in district centres. The study considered the fact that most facilities are located in administrative centre of ATUG – Comrat town. The accessibility taken as a basis for analysis and intervention influences directly the sustainable local development. The accessibility determines the costs that population consumes to reach objects and realize activities in geographic space (Burns, 1979; Miller, 1999; Rodrigue et all, 2009). The accessibility is one of the ensurance premises of population’s necessity in facilities. Starting from the idea that the transport’s role is to insure the connection between the localities and the good markets’ functioning, there exists a high potential for using the models of accessibility with reference to economic sectors and domains ( electroenergetics, education, justice, health, sales markets, agriculture, labour market etc.). Methods and Materials As a research support the transport network of ATUG was digitized by 1:50 000 topographic maps. For a spatial analysis it was constructed a geometrical network of roads of all categories in district boundaries. 12 Table1 Length and time indicators in the automobile road network of ATU Gagauzia All road categories Categories 1-2 Category 3 Category 5 Category 6 Category 10 (km) (km) (km) (km) (km) (km) (km2) (km2) (km2) (km2) (km2) (km2) LENGTH LENGTH LENGTH LENGTH LENGTH LENGTH DENSITY DENSITY DENSITY DENSITY DENSITY DENSITY COMMUNES Ceadar-Lunga 254 2,64 44 0,45 125 1,31 10 0,11 56 0,59 18 0,19 Avdarma 153 2,32 6 0,09 109 1,65 2 0,03 23 0,35 13 0,20 Baurci 213 2,78 9 0,11 151 1,98 6 0,08 33 0,43 14 0,18 Besalma 131 2,15 12 0,20 88 1,44 5 0,08 22 0,36 4 0,07 Besghioz 109 2,06 11 0,21 74 1,41 3 0,06 13 0,25 7 0,14 Bugeac 34 1,86 5 0,26 21 1,17 2 0,11 4 0,22 2 0,10 Cazaclia 241 2,25 13 0,12 170 1,58 8 0,07 29 0,27 22 0,21 Chiriet-Lunga 139 2,37 15 0,25 102 1,74 2 0,03 18 0,31 2 0,04 Chirsova 210 2,04 10 0,10 163 1,59 4 0,04 29 0,29 3 0,03 Cioc-Maidan 155 2,03 12 0,16 98 1,29 7 0,09 30 0,39 8 0,10 Congazcicul de Sus 115 2,73 13 0,31 82 1,94 3 0,07 9 0,22 8 0,19 Copceac 232 2,22 16 0,16 167 1,60 6 0,06 36 0,34 7 0,06 Cotovscoe 29 1,86 2 0,13 23 1,47 1 0,09 3 0,16 0 0,00 Dezghingea 226 2,27 8 0,08 169 1,70 9 0,09 35 0,35 5 0,05 Ferapontievca 71 2,15 8 0,23 51 1,54 3 0,10 9 0,28 0 0,00 Gaidar 121 2,42 13 0,26 77 1,53 4 0,07 15 0,30 12 0,25 Joltai 76 2,11 7 0,18 51 1,43 2 0,05 11 0,31 5 0,14 Tomai 146 1,84 17 0,21 93 1,16 4 0,05 17 0,21 16 0,20 Vulcanesti 394 2,59 51 0,34 230 1,51 13 0,08 62 0,41 37 0,24 Cismichioi 229 2,43 23 0,24 142 1,51 10 0,11 40 0,42 14 0,15 Etulia 113 1,83 14 0,23 76 1,22 5 0,07 12 0,19 7 0,11 Etulia 0 2,53 0 2,53 0 0,00 0 0,00 0 0,00 0 0,00 Chioselia Rusa 27 2,79 5 0,54 12 1,26 2 0,25 4 0,39 3 0,35 Svetlii 59 2,66 6 0,26 43 1,92 1 0,05 10 0,44 0 0,00 Congaz 271 2,09 28 0,22 175 1,35 7 0,05 42 0,32 19 0,15 mun.Comrat 421 2,50 57 0,34 275 1,63 14 0,08 73 0,44 1 0,01 Carbalia 42 3,06 0 0,01 30 2,17 1 0,09 6 0,44 5 0,35 Carbalia 2 8,03 0 2,34 0 0,00 0 0,00 1 5,69 0 0,00 TOTAL 4 213 70,60 404 10,55 2 800 40,13 135 2,08 640 14,34 233 3,50 AVERAGE 2,52 0,38 1,43 0,07 0,51 0,13 13 The network is a vector set af data, represented by nodes interconnected by lines.As nodes can serve localities, facilities, road intersections etc. For a proper functioning of the network in the GIS system there was worked on the formation of a corect topology. The topology supposed to „teach” the network to function as an integral whole. Minor segment errors generate significant errors throughout the whole network, in our case the the road network. For graphical data a base of attributes was created, which included noy only names and categories of the roads, but also the following information: administrative belonging, road categories by quality, distance, time, nodes, crossing directions, bridges, closed roads, asphalted and unasphalted roads etc (Butler, 2008). As a result it was constructed a network with 4 856 nodes and 11 898 arcs. Table 2 Length and time indicators regarding ATUG population accessibility to the administrative centre (Comrat) DIFFERENCE ROUTE STRAIGHT COMPARED SINUOSITY AVERAG LINES ROUTES TO COEFFICIEN E SPEED DISTANCE STRAIGHT T LINES Nr. Minute Hour Locality Meters Km route s s Meters Km Km\h Meters Km 31,06 32,14 Alexeevca 31069 9 24 41 0,68 32148 8 47 1 079 1,079 0,97 14,63 17,29 Avdarma 14634 4 23 19 0,31 17298 8 55 2 664 2,664 0,85 22,34 26,34 Baurci 22340 0 1 57 0,95 26341 1 28 4 001 4,001 0,85 14,55 16,07 Besalma 14552 2 13 22 0,36 16073 3 44 1 521 1,521 0,91 25,53 35,38 Besghioz 25532 2 4 53 0,88 35380 0 40 9 848 9,848 0,72 Bugeac 7571 7,571 11 12 0,20 8215 8,215 41 644 0,644 0,92 49,80 57,70 Carbalia 49809 9 8 102 1,70 57704 4 34 7 895 7,895 0,86 31,66 36,42 Cazaclia 31666 6 3 78 1,31 36424 4 28 4 757 4,757 0,87 30,33 35,77 Ceadir-Lunga 30334 4 31 43 0,71 35772 2 50 5 439 5,439 0,85 25,83 30,02 Chioselia Rusa 25833 3 19 42 0,71 30029 9 42 4 196 4,196 0,86 23,80 27,01 Chiriet-Lunga 23802 2 21 29 0,49 27015 5 55 3 213 3,213 0,88 Chirsova 6452 6,452 14 9 0,15 6498 6,498 42 46 0,046 0,99 14,29 15,39 Cioc-Maidan 14295 5 22 15 0,25 15398 8 61 1 103 1,103 0,93 86,02 94,19 Cismichioi 86023 3 17 125 2,09 94199 9 45 8 176 8,176 0,91 14 21,06 21,23 Congaz 21060 0 16 27 0,45 21236 6 48 176 0,176 0,99 Congazcicul de Jos 6819 6,819 20 13 0,21 7290 7,290 34 471 0,471 0,94 Congazcicul de Sus 8078 8,078 25 15 0,26 9526 9,526 37 1 448 1,448 0,85 49,41 56,56 Copceac 49415 5 7 104 1,73 56568 8 33 7 153 7,153 0,87 18,67 32,05 13,38 Cotovscoe 18670 0 12 42 0,70 32050 0 46 13 380 0 0,58 49,79 63,66 13,86 Dermengi 49798 8 29 119 1,98 63666 6 32 13 868 8 0,78 14,60 15,89 Dezghingea 14608 8 10 23 0,38 15895 5 42 1 287 1,287 0,92 11,47 13,19 Dudulesti 11473 3 27 19 0,31 13199 9 43 1 725 1,725 0,87 86,03 92,54 Etulia 86036 6 18 121 2,01 92541 1 46 6 504 6,504 0,93 88,32 95,18 Etulia Noua 88322 2 26 126 2,10 95181 1 45 6 859 6,859 0,93 11,29 12,56 Ferapontievca 11294 4 15 14 0,23 12566 6 54 1 272 1,272 0,90 22,73 28,52 Gaidar 22734 4 2 43 0,72 28526 6 40 5 792 5,792 0,80 21,04 27,67 Joltai 21045 5 6 38 0,63 27670 0 44 6 625 6,625 0,76 31,96 32,64 Svetlii 31968 8 9 41 0,68 32647 7 48 678 0,678 0,98 14,64 17,95 Tomai 14646 6 5 23 0,39 17959 9 46 3 313 3,313 0,82 70,70 79,68 Vulcanesti 70701 1 30 94 1,57 79685 5 51 8 984 8,984 0,89 1044700, 1044, 134119, SUM 910581,0 910,6 30,0 1508,4 25,1 3 7 1302,4 3 134,1 26,2 AVERAGE 30352,7 30,4 50,3 0,8 34823,3 34,8 43,4 4470,6 4,5 0,9 The highlighting of roads categories started with the idea of accessibility, level of use, content and structure of the road.