Using systems thinking causal loop modelling to analyze the water resources system in Rietspruit sub-basin, South Africa

Abstract A qualitative system dynamics modelling framework was applied in this study to analyze the main driving forces and their feedback interactions influencing water resources management in the Rietspruit sub-basin, South Africa. The dynamics of the water resource system were analyzed using the Vensim™ PLE modelling platform and its archetypes of causal loop diagram, reinforcing and balancing loops. The model visually displayed the causal links of different processes influencing the water resource system and their feedback loops. Special focus was to ascertain and analyze the reinforcing feedback loops within a typical urbanized watershed, with the aim of depicting constraints that could influence sustainable water resource management and adaptation thereof. The causal loop model synthesized that, based on evidence from scientific literature and policy documents, the main driving forces towards the water resource challenges in the study area are associated with rising temperature, degraded water infrastructure and institutional and socioeconomic processes. The study, through the presented conceptual model, offered leverage points and potential pathways for sustaining both water quantity and quality, including infrastructure investment, sustainable revenue generation, decentralized groundwater use and public awareness and participation. The analysis in this study provided a conceptual framework for understanding of interactions of elements within the different systems influencing water resources in the Rietspruit sub-basin. This could be key for ensuring effective and sustainable management of the resource in the context of changing climate and socioeconomic developments.