A decision support tool for equitable and sustainable water management in the Koue Bokkeveld

Abstract

Water is an important natural resource with multiple domestic and industrial uses. South Africa has a water scarcity problem, with domestic and industrial demand projected to increase due to population growth. One affected area is the Koue Bokkeveld (KBV), an agricultural catchment in the Western Cape. Water scarcity, especially in the summer, can cause conflicts among the farmers. This study sought to determine the extent to which Agent-Based (AB) modelling could be used to model the KBV catchment area and simulate future climate and usage scenarios. The study used the ComMod methodology as it allows stakeholders to be involved at each step of the modelling process, thus improving the model's credibility as a decision-support tool (DST). The model was implemented using Cormas, an Agent-Based Model (ABM) implementation framework built with the Smalltalk language. The model was verified and validated through consultations with the catchment coordinator and through workshops with stakeholders. The ABM reflected the catchment characteristics. Farms known to have water shortages had water shortages in the ABM. However, there was one that did not have shortages, which is attributed to land use change. The ABM was used to run multiple simulation scenarios, and it provides simulation results at the crop field, farm and catchment levels, which allows the ABM to be used as a bottom-up DST.