Spatiotemporal analysis of urban sprawling using change detection: a case study of Shaki district, Azerbaijan

Abstract

Introduction. The contemporary globalized world characterizes the rapid population growth, its significant concentration in cities, and an increase in the urban population. Currently, many socio-cultural, economic, environmental, and other challenges are arising in modern cities. Cities are therefore emerging from the common understanding and displaying new characteristics: reduced density, dispersed development, poor accessibility and monofunction. However, the concentration of population in cities also brings its own set of issues. The purpose of article. The purpose of the study was to identify Shaki City's urban development process, and how its land use has evolved over time. It examines the population growth in the region and the increase in the specific weight of the urban population between 2016 and 2023, analyzing the population growth trend over a 20-year period. The direction and extent of urban land use has been studied by determining the relationship between the growth rate of the urban population and the extension of the urban area, and by analyzing the changes which have occurred during the period of land use. Research methods. Statistical data has also been used for this purpose, together with data from the Azersky satellite. Machine Learning (ML), which is widely used in remote sensing systems, was applied, Support Vector Machine Learning (SVM), and image classification and processing were performed. On the basis of the obtained data, a comparative analysis of the previous and current conditions was carried out and the area of changes in the area between the classified areas was calculated. Simultaneously, the changes between categories during the use of the area and the recent changes in the direction of land use were shown. Classification performance has been assessed, user and producer accuracies have been determined and kappas have been calculated. Main findings. The increase in the population of the Shaki district led to an increase in the specific weight of the urban population and the extension of the town to the south and south-east where the population previously lived sparsely. It is mainly due to construction of new housing estates in region, as well as construction of a central clinic, an ASAN service, and a regional education division. A 'flight to the centre' was observed, resulting in noticeable changes in the land use structure between 2016 and 2022, in line with the growth rate of urbanisation and economic development. The decoding of the distribution images of the region shows that there has been an increase in the area of settlements over the six-year period. By 2016, settlements cover 22.4 per cent of the city, and by 2022, the figure rises to 39 per cent. From 34% to 32.9%, the total area of forest reserves decreased. Scientific novelty and practical value The article describes for the first time the urban sprawling and territorial transformations in Shaki district in the context of population growth by using change detection analyses. The practical value of the study is the possibility of using its algorithm and method to conduct similar studies in other cities of Azerbaijan. The results of the study are significant in the context of justifying regional measures to adapt urban expansion to population growth.