CASE STUDY AREA

Urbanization particularly around major urban areas like İstanbul is largely realized by “gecekondu” (squatter) mostly between 1940s to 1990s on the base of shared property which is a common reality and practice in Turkey in spontaneous built up areas prior to an urban plan. Transformation of agricultural lands into built up areas is firstly did by purchase of the land by various holders according an unofficial land division. Then, this shared property is officially recognized and legalized by an urban plan. Therefore, process of transformation is accomplished and agricultural terrain is turned into an urban land.

Here, size of lands matters. Agricultural lands on hills and slopes are more suitable for marketing and commercialization to build on since they are mostly enough big for to divide them into land plots of reasonable sizes (i.e. mostly 200-500 m²). The spatial way of local urban spread confirms this observation and hypothesis. Therefore, urbanized lands displays a tendency to spread from large agricultural terrains around and at vicinity of existing villages (Özaydın et al.;

2010).

Figure 1: Location of district of Sancaktepe at the east of İstanbul metropolitan area (Google, 2014).

The Sancaktepe is one of new districts of İstanbul established only in 2008 and located at the Asian side of Metropolitan Area (Figure 1). It covers an area of 61,9 km² with a population of 304.400 in 2013.

Since 1970s Sancaktepe with its neighbouring areas is experiencing a galloping population increase and rapid urbanization. Population of case study area is increased almost 17 % between 2008 and 2011.

Sancaktepe District where the case study area is located is a dense urbanized area of almost last two decades surrounded by important ecological natural resources. Case study area is within Samandıra neighbourhood and limited with urban areas of similar character developed in recent decades in north and south and with public forests in east and south and water basin protection area of one of Istanbul’s principal water reserves in east (Figure 4).

Figure 2: 1982 aerial image of the case study area in its vicinity (Greater İstanbul Municipality)

Figure 3: 2014 satellite image of the case study area in its vicinity (Greater İstanbul Municipality)

However, the Samandıra neighbourhood which the case area is within its in boundaries was one of oldest villages around. Due to rapid urbanization, the village is turned into a township then, an independent municipality and finally into an urbanized district of greater metropolitan area, from rural to urban in the last fifty years (figure 2, 3). The case study area was an almost distant hamlet with only a handful of land plots in 1950s. However, six decades later, the same area is now a dense, busy urban district at the outskirts of İstanbul metropolitan area. Population of Samandıra village was 351 in 98 houses in 1938. Population reached 4974 between 1970 and 1975 with a slow increase. However, this slow trend will radically be changed after 1980s with a galloping urbanization and population will

reach 61.852 in 1990 and almost doubles itself with 112.653 in 2007.

The squatting or illegal and unplanned constructions (locally

“gecekondu”) is first flourished in second half of 1940s on shared (multi proprietor) and public owned lands in and close vicinity of İstanbul. Squatting reached the Samandıra village of case study area in 1970s and first gecekondus constructed on agricultural terrains.

Physical pattern of land ownership is a lot changed following this and large agricultural terrains are divided into smaller land plots. First maps of land register of the area date of 1956. Whereas first urban planning activities for the region only begun in 1996 and still not finalized. Data related with land plots for different years are as follows:

Table 1: Qualitative Distribution of Land Plots in Case Study Area

Although earliest set of data of case study area goes back to 1960, physical change in land plots is simulated with CA in two periods between years 1990, 2000 and 2014. Total number of land plots, minimum and maximum and most common size of land plots are shown in the Table 1 and distribution of most common size of land plots is shown in Graph 1.

The period between 1960 and 1990 was a period of relative stagnation where fewer significant movements of urbanisation and land division is encountered. First serious sign of urbanisation

and beyond. Increasing number of land plots due to land divisions as the result of new buildings and fastening urbanisation is the evidence of this phenomenon.

Figure 4: Pattern of land plots in Period I (1960) from aerial image of 1982.

Figure 5: Case study area in its close vicinity (2014) and a recent picture of case study area showing urbanized small size land plots in

background with some vacant lands in transition (foreground).

Graph 1: Distribution of Most Common Size of Land Plots According to Years

From 1960 to 1990 number of land plots is increased almost 6,7 times and 2,41 times from 1990 to 2000. However this trend is reversed in following period with a rate of almost 1%. This is due to unification of some land plots. This also gives an important clue about land division process aspect of urbanization. Land plots are divided into smaller pieces until they reache an optimum size. This is mostly an average size between 200-300 m² for Sancaktepe case study area. However, whether small size land plots are suitable for individual houses, but not for use which require large size lands such as industry or land development. Therefore the fragmentation period of previous large agricultural lands through urbanization is then replaced locally here and there by unification where new developments require as the scale of urbanization changes.

Figure 6 show the process of land division and urban spread for years of 1960, 1990, 2000 and 2014 consecutively. Figure 5, clearly illustrates increasing number of land plots through time and locations where urbanizations took place and where small size land plots are reunified to make large divisions. Figure 7, illustrates the way large lands are divided into small pieces through time for periods of 1960-1970, 1970-1980, 1980-1990, 1990-2000 and 2000-2014 and how urbanization process spread on the terrain. Figure 7 is also the visual outcome of CA simulation where red areas correspond living cells where land division process progress and black areas to dead ones where this process is accomplished.

Division of land into reasonable size of plots is a common practice in Turkish urban growth and planning system. Urban planning system and planning legislation in Turkey favors urban development by

decades of low level of capital accumulation and income, urban development through medium size land plots is undoubtedly contributed a lot to land developers and land owners with limited financial resources. This practice was also valid for squatter (gecekondu) type unplanned urban areas and urban growth as in the case of Sancaktepe which is illustrated here. But in this case, size of land plots are generally smaller (mostly 200-400 m²). Therefore, the essence of urban growth in Turkey is division of lands into common size of plots. This may be done via an urban plan or an entrepreneur’s land division of a large terrain without an urban plan.

Anyway the final result will be similar to each other.

Figure 6: Increase and locations of land plots in time through land division

Land register maps on which land plots are clearly shown are regularly used in CA model. Land register maps of 1956 are obtained from local district municipalities and are joined in digital format.

Renewned land register maps due to urban planning applications of 1990, 2000 and 2014 also obtained from the same sources and different coordinates are adjusted thus, every map are harmonized with each other. Changes in each and every land plot in case study area from 1956 onwards are gathered from land register archives and are marked on maps. Therefore, necessary detailled informations such as motives, when and how terrains are divided and to how many blocks and land plots they transformed into are obtained from archive sources. Double check of vector and alphanumeric datas and comparison of changes in land ownership pattern according to different periods are made on aerial and satellite images of 1982, 1996 and 2014.