Impact of rapid urbanisation on land cover in Istanbul Province

Abstract

Since the industrial revolution, rapid urban sprawl has been one of the main characteristics of urbanised areas worldwide. The main objective of this study was to detect, quantify and characterise the changes in land use/land cover (LULC) in Istanbul Province between 2003 and 2015 using a hybrid geographic information systems (GIS)-remote sensing method. Landsat Thematic Mapper and operational land imager images were co-registered and classified using object-based image classification techniques and visual analysis. Land cover maps were rasterized at the same spatial resolution (30 m) in a GIS environment and the same legend was used for both land cover maps. Urbanised areas and other LULC types were determined for the years 2003 and 2015. The extent and spatial distribution of a number of LULC classes in Istanbul changed between 2003 and 2015. Settlement areas increased by 20,464.1 ha in only 12 years and 2529.89 ha of forested land was destroyed for construction of a new highway. Moreover, forests and agricultural areas became highly fragmented. This study confirms the accuracy of the hybrid GIS-remote sensing method. Moreover, the resulting data highlights the extent of the recent rapid land degradation in Istanbul and calls attention to the importance of protecting the natural ecosystems in this area.