How do disasters disrupt the spatial growth of informal settlements? A multi-temporal remote sensing approach – The case study of Mocoa, Colombia

Informal settlements are a growing phenomenon, particularly in the Global South, where disaster risk is also high. This research investigates how disasters can disrupt the growth patterns of multiple informal settlements within a city, focusing on the 2017 Mocoa disaster in Colombia. We propose a novel spatiotemporal framework combining data and models such as historical aerial photographs, RapidEye, PlanetScope multi-temporal images, and deep learning pixel classification models. The framework is translated into a dedicated approach that compares the urban and peri-urban dynamics of twelve informal settlements in the city of Mocoa over 14 years, considering its limited data availability, typical of smaller cities in the Global South. Our analysis reveals that the 2017 disaster significantly altered Mocoa's sprawl pattern and the growth trajectory of specific informal settlements. This study contributes to a replicable methodology in understanding the impact of disasters on informal urbanisation, highlighting the need for disaster risk reduction strategies that consider the vulnerabilities of IS in smaller cities.