Construction clusters in Turkiye's metropolitan provinces: A research on urban spatial growth

Abstract

Metropolitan areas in developed countries are turning into attraction centres and attractive residential areas as a result of the urban policies carried out. In developing countries, on the one hand, metropolitan areas are tried to be obtained with the urban policies carried out. On the other hand, the struggle to create planned spaces and keep urban growth under control continues. In developing countries, the issues related to the acquisition of planned spaces emerge as an extension of uncontrolled urban development at the lowest scale and become problems that affect the whole country. The literature on this subject has a multi-layered theoretical background and offers a comprehensive discussion of the urban spatial policies in these countries. From this point of view, we searched the world literature to understand the ongoing debates on the sustainability of land use, the common mistakes made repeatedly in the production of the built environment, and the urbanisation and metropolitanization process. We determined a bunch of keywords at the beginning and conducted a bibliography search in 2 packs. The first is urbanisation, urban growth, and urban planning. The second is metropolitanisation. Then, we examined the urbanisation and metropolitanisation process of the American continent, the European continent and particularly the history of Istanbul throughout the Ottoman Empire and the Republic of Turkey. Our main aim was to understand the process experienced in Turkish settlements and to compare and relate them to world examples. While doing this, we went beyond the usual doctoral research and followed the inductive method. By examining the world literature, processes in different geographies and current research examples, we have created a research design that will deal with the metropolitanization process in Turkey in the most comprehensive way. While the negative effects of the uncontrolled urbanisation and metropolitanisation processes experienced in the world literature of the study on land use diversity in developing countries come to the fore, we saw that evaluations could be made regarding their positive contributions when socio-economic development is taken into consideration. In the world literature and legislation review, we noticed that administrative borders define Türkiye's metropolises, while world metropolises are defined by their functional urban areas. Thus, we determined the main hypothesis: "Urbanization in Türkiye is shaped by legislation". In addition, since there is no criterion other than population in our country's legislation, we have determined essential criteria based on the literature to understand whether each province in Türkiye is a metropolitan municipality, unlike the criteria set by the OECD and other international organizations. The research covers all provinces of Türkiye and examines the spatial reflections of urban policies by focusing on metropolitan areas. In doing so, we traced the development of metropolitan areas, changes in national spatial policies and their impact on settlements. We tested the widespread discourse that the urban-spatial policy implemented is a "process" based on the built environment in Türkiye's provinces. In addition to the claim that the urban agglomeration in İstanbul, which is both the dominant and metropolitan city of Türkiye, also affects the surrounding provinces, we examined the relationship between İzmir, which was declared the first metropolitan municipality, and Ankara, with its neighbouring provinces in their geographical location. While trying to dispel the assumption that there is a strong link between the increasing building mass in settlements and urban development policies with a Spatiotemporal analysis, we examined the clustering trend of building permits. We revealed in which direction the structural eaves from clusters and clusters are moving. We have seen that being a metropolitan area in Türkiye and the rest of the developing countries means urbanisation, and urbanisation means increasing structuring in terms of area and volume. In line with the statistical results, the legislation and the literature readings, we saw that the acceleration trend in urbanisation and construction in Türkiye parallels the spatial policies that continued as of the 1980s. We found that institutional changes in metropolitan areas in the 2000s supported this process. At this point, it is essential to state that Türkiye's rural settlements are more extensive than urban areas and that it is a country of agricultural production, so the sustainability of land use diversity is the most crucial issue in both metropolitan and non-metropolitan provinces. Considering the current period, we should emphasise that in today's climate crisis, even in the name of urbanisation, political decisions that will pave the way for endangering rural settlements and agricultural production cannot be taken haphazardly, or they will have devastating consequences. Acquiring data from official sources is still a significant problem in most of the developing countries, and open data sources are also limited. Our research shows an alternative way of reading the metropolitan city network by establishing the uncontrolled urban growth fuelled by construction, using the Moran Index, which is used to read spatial political trends, and evaluating building occupancy permits from a different perspective by overcoming the problem of finding firm data sets. In order to make an in-depth Spatiotemporal analysis, we evaluated the building permits collectively and looked at the development trend of Türkiye for the last fifteen years, then focused on the four years following law no. 6360, which came into force in 2013, was the breaking point of the metropolitan legislation. We obtained the building permit data from TURKSTAT, made spatial analyses using GIS-based software(s), and visualised the statistical results. First, we used exploratory spatial data analysis to reveal the clustering trends of all building permits, then residential buildings in order of priority, then industrial, commercial, tourism, educational and cultural buildings, cluster centres, and if any, clustering capacities and sustainability of this capacity. In addition, we verified its consistency with Pearson Correlation before using the data set in statistical analysis. We applied the Moran Index as a module within the ArcGIS program to search for construction clusters, We also analyzed the same data in the GeoDa program to see how clustering was affected when changing datasets and to confirm the accuracy of the results, and crossed it with Spatial Lag results between 2014 and 2017. We evaluated the last real estate unit sales changes from rural plots to urban service parcels over the transaction volume for the same period examined in detail. We aimed to evaluate the distribution and density of the building occupancy permits, which we compiled into seven categories, and to evaluate the construction clustering capacity of the provinces through the existence of a metropolitan municipality and the presence of a top-scale plan. During the time studied in detail, complex patterns emerged on the maps. The provincial clusters and cluster centres that emerged as a result of the analyses increased our ability to understand and interpret the connection between the increase in construction and urban development. In addition, a network structure has emerged among the provinces. The existence of the top-scale development plans guided us as well. The research revealed an alternative way of reading the metropolitan network through construction by data and analysis. In addition, the visuals of industry, tourism and commercial building permits made it possible to read the provinces that are more preferred for construction in general and the type of construction investment. The obtained results define the country's current land use and regional diversity. The network of metropolitan municipalities in Türkiye and the physical space potential of cities are revealed by building mass clusters based on the type of construction and the trend of construction types in both metropolitan and non-metropolitan provinces. With this research, we conducted a country-level study on the effects of urban sprawl, integrated urbanization and increasing construction in the surrounding provinces related to construction and construction activities through ongoing urban spatial policies in Türkiye, and we are satisfied with the obtained results. In Türkiye, we have put forward an empirical study in accordance with the analytical and the followed research method, which enables the reading of the urban policies carried out in the neo-liberal period through space, containing findings confirmed by analyses. As mentioned above, the metropolitan areas' legislation is from the old-world order and narrow-scoped, where urbanisation matches construction investments. In the conclusion part of this research, the provinces that can be selected as pilots and need to be examined to control the devastating consequences of construction-based growth are included, and their reasons are shared in detail in the analysis part.