Namibia, the driest country in sub-Saharan Africa, sees a large portion of its population dependent on pastoralism. One particular example are eastern Namibia's semi-arid rangelands where pastoralism has been securing livelihoods for the local Herero communities for centuries. However, these areas face increasing pressure from factors like increasing drought frequency and woody plant encroachment, depleting productive grazing areas and placing livelihoods at risk. Despite studies on drought and degradation, there is limited understanding of how these intertwined factors, including climate and financial shocks, population increase, and changing management strategies, shape the resilience and livelihood security of these communities. To address this research gap, we developed an agent-based model to explore the long term social-ecological dynamics of a communal pastoralist semi-arid rangeland. The model simulates interactions between pastoralist households, their herds, and the rangeland environment, incorporating processes like rainfall, vegetation growth, grazing, and household decision-making. We analysed three scenarios: the impact of increasing population density, the system's response to climate and income shocks, and the effectiveness of income-related mitigation strategies. Keywords: Agent-based modelling, pastoralism, rangelands, shocks, social-ecological system, tipping point.