Urban Sprawl Symptoms in Ngaliyan and Mijen Sub-Districts of Semarang City in 2015, 2019, and 2023

Rapid population growth and urban expansion have become critical issues in achieving sustainable spatial planning, particularly in urban fringe areas where uncontrolled settlement development is increasingly prevalent. This research focuses on the Mijen and Ngaliyan Sub-districts in Semarang City, which represent peri-urban zones. The objective of this study is to map the extent and typology of urban sprawl through a spatially explicit approach using Geographic Information Systems (GIS). GIS analyzed urban sprawl utilizing the ratio of population distribution to built-up area at the subdistrict level in 2015 and 2023. A weighted scoring method was applied using five parameters: population density, building density, network-based distance to the city center, buffer-based highway strip index, and leapfrog development index derived from settlement distribution. The results show that no low-level sprawl classification is present in the identified villages. The medium level includes Ngaliyan, Tambakaji, Kedungpane, Bubakan, and Pesantren. Meanwhile, the high classification includes Jatibarang Village and Bambankerep Village, characterized by rapid, unplanned growth and limited infrastructure connectivity. Additionally, Grid-based spatial analysis was employed to classify sprawl typologies, and ribbon development that emerged as the dominant typology, concentrated along major road corridors. This research offers spatial evidence to support urban development policies and promote more sustainable growth in peri-urban areas of emerging cities.