Utilising GIS as a tool for anticipatory governance: Mapping current and future flood risk in the eThekwini Metropolitan Municipality

Abstract

Flooding poses a significant disaster risk to inhabitants of the eThekwini Metropolitan Municipality in South Africa. The rapid growth of informal settlements and climatic changes have led to increased vulnerability to flooding events, as evidenced by the floods of April 2022 in the eThekwini Metropolitan Municipality. Arguably, the lack of proactive identification and mapping of flood-vulnerable areas have hindered effective disaster preparedness and mitigation efforts in the city. Given this research gap, this study integrates geographic information systems (GIS) with anticipatory governance (AG) principles to map current and future flood risks, focusing on identifying vulnerable informal settlements in the eThekwini Metropolitan Municipality. The research employs a multi-criteria decision analysis (MCDA) approach, incorporating seven key factors: land slope, elevation, rainfall patterns, drainage density, soil type, land use, and distance from rivers. The methodology combines current flood risk mapping with future scenarios based on different shared socioeconomic pathways (SSPs), projecting potential changes in precipitation and informal settlement growth by 2050. The study applies a pluralistic futures approach to AG to develop multiple flood risk scenarios. Key findings reveal that 289 informal settlements, housing approximately 163 000 households and covering 34.7 km², currently face extremely high flood risk. The study's cross-scenario analysis identified 230 informal settlements, spanning 29.2 km², that consistently show extremely high flood risk across the current as well as all the future scenarios. Future projections indicate potential increases in at-risk areas, with up to 69.9 km² of informal settlements facing extremely high flood risk by 2050 in the most severe scenario (SSP5).

The research demonstrates the effectiveness of integrating GIS and AG principles for flood risk assessment and management. The research further provides a robust framework for prioritising interventions and developing adaptive strategies for flood risk mitigation in informal settlements. The multi-scenario approach offers valuable insights to decision makers, enabling them to makemore informed decisions in the face of climate change and ongoing urban growth challenges in the eThekwini Metropolitan Municipality. Combining GIS capabilities with AG principles offers a replicable methodology for other cities facing similar challenges. The findings of this study highlight the need for proactive urban planning and targeted interventions to enhance the resilience of informal settlements against flood risks.