Characterizing Informal Settlement Dynamics Using Google Earth Engine and Intensity Analysis in Durban Metropolitan Area, South Africa: Linking Pattern to Process

The growing population in informal settlements expedites alterations in land use and land cover (LULC) over time. Understanding the patterns and processes of landscape transitions associated with informal settlement dynamics in rapidly urbanizing cities is critical for better understanding of consequences, especially in environmentally vulnerable areas. The study sought to map and systematically analyze informal settlement growth patterns, dynamics and processes, as well as associated LULC transitions in Durban Metropolitan area, from 2015 to 2021. The study applied an object-based image classification on PlanetScope imagery within the Google Earth Engine (GEE) platform. Further, intensity analysis approach was utilized to quantitatively investigate inter-category transitions at category and transition levels. Thus far, no study of land conversion to and from informal settlement areas in South Africa has exploited both GEE and intensity analysis approaches. The results suggest spatial growth of informal settlements with a total net gain of 3%. Intensity analysis results at category level revealed that informal settlements were actively losing and gaining land area within the period, with yearly gain and loss intensity of 72% and 54%, correspondingly, compared to the uniform intensity of 26%. While the growth of informal settlements avoided water bodies over the studied period, there was an observed systematic process of transition between informal settlements and other urban land. Government policy initiatives toward upgrading informal housing could be attributed to the transitions between informal and other urban settlements. This study illustrates the efficacy of intensity analysis in enhancing comprehension of the patterns and processes in land changes, which aids decision making for suitable urban land upgrading plans in the Durban Metropolitan area.