1 IntroductionUrbanisation, both in developed and developing countries is increasing rapidly. Over 45% of the people in the world live in urban areas. In addition; the annual population growth rate is 2.4% in urban areas, while it is 1.7% in rural areas. Rapidly growing regions with major metropolitan regions in both developed and less developed countries face specific problems. The uneven growth causes urban sprawl which generates changes in the distribution of land use types and creates economic, environmental and sociocultural implications for the country.Turkey is one of these developing and growing countries. Istanbul, being the most metropolitan city in Turkey, has the highest immigration rate. While the average population increase rate is 2.2% in the country, it is 3.8% in Istanbul. The population and urbanisation in Istanbul has increased due to severe immigration rate from rural areas to access job opportunities, better education and better health facilities in the city.Istanbul has consistently been at the centre of academic research in Turkey since the city is considered to be a microcosmic reflection of the social and urban change of the whole country. Being from Istanbul and getting to observe the uneven growth of the city and its effects over the years directly, Istanbul was chosen to analyse the implications of urban sprawl in this essay. In the next section, urban sprawl in general will be examined; to have a better understanding of the following section which is specifically about urban sprawl in Istanbul. The sprawl in Istanbul will be structured chronologically by analysing the urban development of Istanbul since 1950s. Subsequently, the effects of urban sprawl in Istanbul on economic, environmental and sociocultural levels will be deduced.2 Urban SprawlWhat is urban sprawl?No definition of urban sprawl has been universally accepted yet. However, several researchers have defined this term in their own ways. For instance, Brueckner interprets urban sprawl as the excessive spatial growth of cities. In an urban sprawl pattern, both residential and nonresidential developments take place in a noncontiguous way, outward from the central city. These developments usually form through the devouring of agricultural and other fragile lands beyond the existing urban boundary. Fig. 1 Whereas, Galster implements a conceptual definition of sprawl based on eight dimensions of land use patterns; which are density, continuity, concentration, clustering, centrality, nuclearity, mixed uses, and proximity. According to this interpretation, sprawl is a condition where the values of these dimensions are low.Why sprawl matters?The increase of urban sprawl as the immediate form of urban development in recent years, is under criticism because of its unfavourable economic, environmental and sociocultural effects. The expansion of cities and the constant desire of development, at the cost of free areas and natural resource lands has triggered intense interest and arguments over the consequences that urban sprawl brings.Urban areas in both developed and developing countries are increasingly feeling the effects of urban sprawl such as climate change, resource depletion, food insecurity and economic instability. These are all factors that significantly reshape towns and cities in the century ahead. Therefore, urban sprawl matters because all of these factors need to be effectively addressed if cities are to be sustainable, that is, environmentally safe, economically productive and socially inclusive.The impacts of urban sprawlThe costs and negative impacts of urban sprawl have been widely studied and it will be summarised in four main points in this section. First is the increase in travel and congestion. Excessive residential development without consideration of employment centre locations leads to longer trip lengths and produces negative environmental effects. Secondly, as a result of the first impact, is the increase in energy consumption and air pollution. Studies have consistently found that compact development is more energy-efficient than low-density sprawl.Third is the degradation of agricultural and environmental resources. New single-family detached housing consumes agricultural and other environmentally sensitive areas, leading to a decrease in available land and the deterioration of the environment in the long term. Greenfield development is favoured by developers in a competitive economy because it is simpler and more profitable to develop greenfield lands due to low land values.Finally, there is the seclusion of older neighbourhoods, deterioration of central areas and decline of social interactions. Urban sprawl disrupts social stability and increases economic disparity between older neighbourhoods and newer suburbs. In addition, the branching out of employment centres have become problematic for older neighbourhoods because the new jobs are inaccessible to the poor and the working class.Responses to urban sprawlIn response to concerns about sprawl, compact development strategies and policies have been adopted by local governments and countries to promote sustainable development and environmental conservation. Some of these strategies include the establishment of physical containment policies, such as Greenbelts, Urban Growth Boundaries, and Urban Service Areas, as well as, the imposition of development fees, encouragement of urban development towards infill, and restrictions on residential capacity.3 Urban Sprawl in IstanbulUrbanisation in IstanbulIstanbul, with its almost 15 million inhabitants and a yearly growth rate of 3.5%, primarily due to internal migration from rural areas, has been growing since urbanisation has started in the city. Therefore, sprawling urban development and the associated conversion of rural land have become an important issue for Istanbul. As seen in many other big cities around the world, the population of Istanbul began increasing very rapidly especially after the World War II. The city’s population was only about a million in 1950; however, the population almost doubled by 1960 and then became three million in 1970. This increase in population continued after 1970 and Istanbul became a megacity with its ten million inhabitants in 2000. Due to this, the city has faced huge problems of growth and its structure has continued evolve. The unavailability of planned settlements, high costs of planned areas and other socioeconomic and political factors resulted in the establishment of many illegal urban areas starting in the 1950s. Since then, Istanbul’s urbanisation has had three main phases.——————————————————————————————————-Phase 1: slumsSlums (referred to as “gecekondu” in Turkish) which are early village-like developments on squatted land were the first response to the housing shortage in the growing industrial city. The rapid population growth has increased the formation of slum populations in Istanbul and encouraged the formation of illegal one or two-story houses built very fast in poor quality. Fig. 2 The period between 1950 and 1960, following industrialisation, the influx of working class populations increased, while the need for human labor in farming decreased. Consequently, migration from rural to urban areas intensified, as well as the housing demand. The outcome of this issue was the evolution of even more slum neighbourhoods around the city.Phase 2: post-slumsStarting in the 1970s, most of the slum plots were legalised and granted additional building rights. The local government signed over property rights to squatters instead of investing in social housing. These slum neighbourhoods constitute the nuclei of many sub-provinces of Istanbul today. Fig. 3 During this expansion, Istanbul has grown mostly in the west and east, where agriculture and bare soil were the dominant land use types, and natural barriers like the sea in the south and the forest in the north forced urban growth to continue along the coast of the Sea of Marmara.As a consequence of rapid industrialisation and population increase, growth of the city through the peripheries introduced the need to link urban areas through transportation systems. However, the construction of the E-5 motorway and the first bridge over the Bosphorus in 1973 triggered urban sprawl instead of providing a sustainable solution, and Istanbul became an “overgrown industrial city” by the 1980s. The construction of the bridge especially expanded urban growth in the north along both sides of the Bosphorus.Peripheral highways have also had a significant impact on suburbanisation and retail expansion patterns in Istanbul, accelerating urban sprawl to the edge of the city. An increase in accessibility has affected the location of new residential settlements and firms. Major highway intersections have attracted some retail and office space development. Industries and other firms have established themselves at the periphery, in search of lower land and transportation costs, while large plots for modern office buildings and shopping malls have been constructed. This commercial restructuring of the city has led to different types and sizes of commercial facilities at suburban ‘corners’ contributing to the outward expansion of the city. As a result of all this suburbanisation, new subcenters have emerged and ongoing population growth resulting in multi-centred peripheral development has dominated the development of the city.Although the historical Central Business District of Istanbul started to descend in the 1970s as a result of suburbanisation, it began to restore after the 1980s with the aid of revitalisation projects. During the 1980s, a second wave of migration brought migrants to the abandoned historic buildings in central areas due to these projects. This trend introduced concerns about heritage conservation, along with the regeneration of the waterfront and abandoned industrial areas. These renewals were conducted with the idea of eliminating pollution while increasing the land value of the area and promoting a new image of Istanbul as a global city. In this period, the urban skyline of Istanbul changed severely with high-rise office towers, luxury apartments, international hotel chains and shopping malls. Meanwhile, the Central Business District developing in the north, led to the construction of a second bridge over the Bosphorus in 1988. Fig. 4Phase 3: mass housingSince the 1990s, Istanbul has had exceptional mass housing development. Fig. 5 This development, which varies from the earlier phases based on “self-building” is coordinated primarily through the housing development agency of Turkey, which is TOKI, in partnership with larger private enterprises. TOKI was established in 1984 in order to act as the public landowner and stakeholder in private developments or as the public developer of mass housing. TOKI has essentially used a single urban typology: clusters of towers on open land, resulting in gated complexes with surrounding protective walls. As a continuation of this, the private sector also adopted this typology to build which are perceived as most effective and profitable.21st century in IstanbulThe beginning of the 21st century brought the rise of the Justice and Development Party as the ruling party from 2002 to the present and following the financial crisis in 2001 economic growth was achieved through subsequent macro developments. Over the last 20 years many global city concepts have been produced for Istanbul. Central government and local authorities have proposed various projects to make Istanbul a global city. With these projects coming alive, Istanbul’s urban character has been changing completely and the city has been growing with excessive heterogeneity, specifically in its urban housing and mega-projects, as never before. Turkey’s “Vision 2023” defines a set of goals to be reached by the centennial of the Republic of Turkey, emphasising the importance of public infrastructure investments in further economic growth. Amongst the numerous projects; the construction of the third bridge over the Bosphorus (completed), a new waterway connecting the Black Sea to the Sea of Marmara (Kanal Istanbul) and the third airport are the noticeable ones. These projects all continue to promote urban sprawl and add to its negative effects.———————————————————————————————————4 Effects of Urban Sprawl on IstanbulEconomic effectsEconomic policies always had a strong effect on urban growth and change in Turkey. In each period, the urban space has been shaped by the economic policies of the government. The construction sector represents a by-product of economic growth, which means the construction sector follows economic growth rather than contributing to it. For example, period of 2010–2014, the low interest rates and amendments in urban legislation raised the construction sector and positively affected the economic growth. Although there were some periods when construction industry growth therefore urban sprawl had positive effects on economic growth; these were short-lived effects that could not offer stable solutions for the economic troubles in Turkey because construction sector is highly dependent on economic stability.Especially the urban transformation projects of the 21st century, which require detailed analysis process over a long term for the benefits of the society, are in short term agenda for Turkey and consequently Istanbul became a resource of investment in global economy. Although these projects create some employment, they essentially generate huge profits for the ruling party’s backers. The building industry has become the backbone of rapid development. Speed, however, is often synonymous with an unchecked, unbalanced, unaccountable way of working concerning the environment. Prioritising speed and cost; these projects are often exempt from Environmental Impact Assessments or Strategic Environmental Assessments.Environmental effectsMany current environmental problems in Istanbul are directly or indirectly related to rapid urban growth and sprawl. Urbanisation has significant effects on our natural environment and the services it can supply to humanity. The environmental effects of urbanisation started in Istanbul with the formation of slum populations. These illegal and unofficial residential areas started to interfere with the water resources, forest areas, and high-quality agricultural land around the city. Moreover, the construction of bridges on the Bosphorus and the Golden Horn changed the accessibility of different areas to one another and therefore caused a spatial conversion in the land use pattern. The forest areas in the north which contain rich flora and fauna, water basins and natural resources have been affected by these developments as well. Thousands of hectares of land lost their forest characteristics due to illegal housing development and Istanbul lost around 5% of its forest area between 1973 and 1995 due to urban growth.With the current mega-projects in Istanbul, deforestation and losing green areas to business development is a serious concern when the scale of the projects is taken into consideration. Fig. 6 For example, 80% of the total project area of the third airport consists of forested land. One of the direct effects of deforestation is associated with anthropogenic climate change. The heat island effect, caused by the destruction of forests for land-use and transportation, threatens the health of the urban environment. There is an expected increase in regional air pollution when the natural carbon cycle is interrupted. In addition, the rise of the land traffic will further increase emissions along the access roads, due to the wider road networks connected to the third bridge and tunnel portals.There are also problems connected to ecosystems. Union of Chambers of Turkish Engineers and Architects warns that Istanbul will be deprived of water as the construction sites of some current projects are in ecologically protected and sensitive areas including water basins. According to the ESIA report for the third bridge and connected motorways, the main route passes through the northern border of the Belgrade Conversation Forest and Bosphorus Key Biodiversity Area. These areas consist of a wide range of habitats, forests and lakes, as well as several vulnerable habitats with rare plant species. Fig. 7 These environmental effects cannot be limited to the area of construction, since the mega projects will launch the conversion of the region into new usage areas.Sociocultural effectsUrban sprawl also effects Istanbul in a sociocultural way. For example, the start of mass housing of TOKI developments in 1990s is parallel with the rise of a new middle class as a dominant class in Istanbul, which reflects a worldwide condition within global capitalism. Continuous advertisement campaigns on mass media construct a narrative dream for Turkish families: car ownership and an apartment comfortably decorated and equipped with the latest technology. A TOKI flat is the first step in executing this dream even if the price to pay is isolation, reduced social relations, long journeys to work, hours spent in traffic jams or shopping in massive malls, high service and maintenance fees and long terms debt.Additionally, quitting the principle of using the public land stocks for the needs of the society with the planning approach of 2000s, gives rise to various applications which form threats in terms of the urban rights and the liveability of the city. These lands are considered as the potential for unearned incomes. Their market values are increased by several times for the new functions and new structuring rights. The participation of the public in the competition of obtaining unearned incomes, in addition to the companies and individuals, creates problems. Ignoring the life quality concept for the purpose of ensuring finances suggests danger not only for the unique character of Istanbul but also for the life of its citizens.Another result of the greedy non-participatory planning approach is that new development doesn’t fit in to the existing context nor how the citizens would like to see the city developed. The Golden Horn Metro Bridge which opened in 2014 is a recent example of this. Fig. 8 The cable-stayed bridge has a very modern design that doesn’t really cohere to the historic context of the area and therefore the historic atmosphere is not protected well enough.——————————————————————————————————-5 ConclusionDespite all the current and potential economic, environmental and sociocultural disadvantages, Istanbul continues expanding the limits of its growth and sustainability. A primary reason for this is the uncontrolled and unplanned urbanisation policy in Istanbul. As a result of the heavy immigration growth, the expansion of the city could not be controlled since the start of urbanisation and further on to the present this took the form of making profit through the construction sector. Although it can be argued that mass housing, new developments and urban growth are beneficial for the economy and newcomers in a certain way, it also makes designing a building a tool to make profit and making it distant to architecture.In the near future, the anticipated growth towards the north should build up new centres of global competitiveness in Istanbul, but the issues of deteriorated natural resources, property rights and expected migration flow could disrupt the existing urban fabric and decline social interactions. Therefore, the attractiveness of new developments could be lost easily, especially with the latest globally promoted imperatives of environmental awareness and social coherence.
These negative effects of urban sprawl, present a need for an inquiry into the planning approach in Istanbul. Controlling urban development processes is essential to promote a sustainable urban development, especially under conditions of rapid urban population growth which is the case in the city. Therefore the government should adopt strong urban containment policies to deal with urban sprawl and to promote more sustainable development. The analysis of the policies that the government is performing currently and what can be improved could be further researched and studied as a proposed solution to the rapid and uneven urban growth in Istanbul.