Feedback modelling of the impacts of drought: A case study in coffee production systems in Viet Nam

Drought is a major cause of crop failure and livelihood insecurity, affecting millions of people across the world. A changing climate, increasing population and economic growth are exacerbating water shortages, further interrupting agricultural production. Assessing and minimizing the impacts of drought require a thorough understanding of the interrelationships and interactions between the climate system, ecosystems and human systems. In this paper, we apply causal loop modelling grounded in systems thinking theory to examine the interdependencies and feedback processes among factors associated with drought that impact crop production using a case study of Robusta coffee production systems in Viet Nam - the world's second-largest coffee producing country. Our model, underpinned by qualitative data from consultation with a range of stakeholders, indicates that water depletion affecting coffee cultivation is not solely attributed to rainfall insufficiency but an outcome of complex interactions between climate and socioeconomic systems. Our analysis highlights that uncontrollable coffee expansion, largely at the expense of forested areas, is partly the unintended consequence of policy decisions, including those encouraging migration and perennial crop development. Growing water demand in the region, including the demand for irrigation water driven by the ever-increasing area under coffee cultivation, as well as inefficient irrigation practices are placing significant pressure on water resources. A changing climate may exacerbate the problem, further impacting coffee cultivation, unless adaptation practices occur. A number of potential interventions are suggested, including explicit zoning of coffee-growing areas; awareness raising for wide adoption of optimal irrigation practices; converting Robusta coffee monocultures to diversified systems; and strictly protecting existing forests coupled with afforestation and reforestation. These interventions should be simultaneously implemented in order to adequately address drought and water scarcity for coffee production and build resilience to climate and market risks.