Assessing trade-offs between agricultural production and wetlands preservation in Limpopo River basin: a participatory framework

Wetlands in the Limpopo Basin support the livelihoods of many poor people through agriculture for both food production and income. Wetlands are used to mitigate the problem of low crop yields associated with low rainfall and droughts. However, wetlands are complex and ecologically sensitive environments, which fulfill other important environmental functions, such as flood control or groundwater recharge and discharge. Consequently, altering the wetland environment through cultivation has potential impacts not just within the wetland but also in downstream areas. In a context of escalating unemployment and unreliable rainfall, it appears difficult to prevent further development of wetlands for agriculture. However it is also important to ensure that this development does not compromise environmental security. Sustainable management of wetlands cannot be achieved without active participation of all stakeholders, including local communities and environmental groups. Despite the abundant literature on sustainable use of wetlands, there are few decisionsupport tools designed to assist stakeholders in their choices. Different approaches exist to assess the value of natural resources such as wetlands, according to types of use (e.g. consumptive/non consumptive, productive/non productive). Nevertheless, they provide values that are difficult to compare, and that furthermore reflect a balance of human activities that is likely to change over time. The framework proposed in this paper aims at analysing the tradeoffs between wetlands uses by local population and preservation of environmental services, in order to support decision-making by policy makers and wetland users. The framework is based on a combination of participatory methods, observations, surveys and simulation tools to diagnose and analyse the present uses and the ecological status of the wetland. Several multidisciplinary models (hydrological, agronomic, economic models and GIS) will be interconnected to represent the complex relationships between ecological processes and human activities in the wetland. Simulation of various scenarios of land use and farming practices will help at assessing the trade-offs among these uses and the trade-offs between them and the provision of environmental services by wetlands.