Utilizing UAV for the Detection of Vacant Urban Spaces: Implications for Sustainable Infill Development

Vacant and abandoned land are important sources of endogenous urban development. Ahvaz, one of the largest cities in southern Iran, has undergone significant physical expansion. Consequently, identifying suitable land for new development is essential for urban authorities. This research aimed to identify vacant urban land in Ahvaz using UAV images. The identification process was based on two criteria: "Urban Morphology" and "Distribution Pattern," which guided the extraction of urban vacant lands. The methodology included standardized image processing, categorization of vacant spaces, and statistical analysis to ensure accuracy and reliability. The first step was to identify the location of vacant lands in Ahvaz using images. Next, suitable locations for infill development were categorized into 6 groups based on their number and area. The density and distribution of these spaces were then examined using the index of the shape of the vacant plots and the Kernel function. The findings revealed that the largest area of vacant land was categorized as "barren with vegetation." In terms of distribution patterns, zones 2 and 1 of Ahvaz city exhibited the largest and smallest vacant land areas, respectively. This indicates a correlation between urban development levels and the availability of vacant spaces, suggesting that more developed areas tend to have fewer vacant lands. Moreover, zone 2 had the largest amount of vacant land in the town, followed by zones 8 and 6.