IDENTIFICATION OF SPATIAL CHANGES IN THE YOGYAKARTA METROPOLITAN AREA USING THE URBAN INDEX APPROACH

Abstract

Urban area growth is a complex spatial phenomenon that requires analytical approaches capable of accurately revealing the dynamics of spatial change. This study aims to identify spatial changes in the Yogyakarta Urban Area (KPY) during the 2014–2024 period using the Urban Index approach, developed through the integration of Night-Time Light (NTL) data and the Normalized Difference Built-up Index (NDBI). This method was employed to detect the spatial distribution of urban activities and settlement density, which were then validated using 2024 land cover data. The analysis classified the Urban Index into five main categories—Non-Urban, Transition Zone, Periphery, Fringe, and Urban Core—allowing for a comprehensive examination of the spatial structure shifts within the urban area. The results indicate that the Urban Core experienced significant intensification in the center of Yogyakarta City, while the Fringe and Periphery zones expanded considerably into peri-urban areas, particularly in southern Sleman and northern Bantul. Validation with land cover data revealed extensive conversion of agricultural land, especially rice fields, into residential and other built-up areas, which aligns with the Urban Index patterns. Accordingly, the dynamics of KPY’s growth between 2014 and 2024 are characterized by increasing urban density at the core and the outward expansion of urban activities into peripheral zones, signifying a spatial transformation shifting urban development orientation from the core toward the peri-urban areas. This study recommends the implementation of spatial management policies focused on protecting productive land and promoting a more sustainable urban spatial structure.