Impact of Resilience Policies on Cape Town's Water-Food Nexus: A System Dynamics Approach

Abstract

Background Climate change is increasingly affecting the supply of resources such as water and food. From 2015 to 2018, Cape Town endured its most severe drought on record. Yet, resource management often occurs in isolation, which contrasts with the holistic perspective provided by the nexus concept that recognizes the interdependence of resource sectors. This study employs system dynamics modelling, to examine the City of Cape Town’s (CoCT) water-food trade-offs and interactions using qualitative and quantitative approaches. It assesses various policies proposed by the CoCT, to improve system resilience and to boost future water supplies, examining their efficacy and potential drawbacks. These policies are tested against future scenarios including population growth and climate change predictions of different severities. Results The simulation results show an increase in food demand, which is mainly linked to population growth and a significant decrease in water availability. Without interventions, the CoCT is expected to experience serious water shortages within the 40-year simulation period. Conclusions The findings indicate that the CoCT’s strategies will effectively secure adequate water for its expanding population. However, a major concern was found to be the proposed intensification of aquifer exploitation. The model predicts that such an approach could lead to over-abstraction of some aquifers, compromising their sustainability.