Analysing the urban sprawl increase in the Maltese islands by remote sensing and Geographic Information Systems

Abstract

Anthropogenic activities such as waste dumping and natural activities such as volcanic eruptions are constantly changing the natural environment. The Maltese Islands have experienced a lot of changes, mostly due to uncontrolled development and a rapid increase in the population. Rural areas have been transformed into urban areas, in a process known as urbanisation. The aim of this research is to analyse the urban sprawl increase and the land cover change on the Maltese Islands, using Landsat satellite imageries from 1999 and 2019. Population change was also considered in the following analysis. The Landsat images were atmospherically corrected to remove any radiometric errors on the satellite images, and the images were classified with the minimum distance classification. The images were evaluated using accuracy metrics. The results showed that the overall accuracy of the classified images was higher the standard of acceptability in thematic mapping (85%), however, the quarry class failed to reach this target. The supervised classification results were very similar to each other. Changes in the built-up area were minimal and they were mainly found at the outskirts of certain Maltese villages and towns. However, aerial images have a limitation that they cannot capture differences in vertical elevation. In an attempt to contain horizontal spreading on the Maltese Islands, the Planning Authority relaxed the height limitation policies by allowing for higher-rise buildings based on a formula. Between 2000 and 2020, the board of the Planning Authority approved more than 9,000 permits for the demolition and the construction of urban dwellings. Most of these permits were for higher-rise buildings. Therefore, the urban growth on the Maltese Islands was reflected in vertical urbanisation more than horizontal spreading.