Using spatial information to improve collective understanding of shared environmental problems at watershed level

The decrease in stream water quality due to intensive agriculture is an environmental problem of concern in various parts of the world. This problem may not be appropriately addressed due to insufficient knowledge of its causes, in particular, the locations of the primary pollution sources and the relative magnitude of the problem under different management scenarios. In some situations, this information may be known but not adequately communicated to, or perceived by, the stakeholders who should decide on corrective action. A participatory approach, which includes the negotiation between suppliers and users of information and visualisation of scenarios, could be a powerful tool to overcome these inadequacies. This paper describes the provision of spatial information and the results of spatially explicit pollution modelling exercise to stakeholders in a participatory workshop, and evaluates the extent to which this information influenced decision-making. Workshops were organised with farmers and extensionists in the west region of Santa Catarina State, Brazil. Spatial information (synoptic satellite image, orthophoto mosaic, location of pig producers) and results from a spatially explicit dynamic pollution model (AgNPS) for previously prepared scenarios were presented. Questionnaires were administered at four different times during the workshops to test participants¿ reactions to, and opinions of, the information provided. Participants were able to understand and react to the spatial information despite their lack of previous exposure to such materials. Both visualisation and discussion caused major shifts in perception of the problem and suggestions for solutions. Participatory visualisation of scenarios enhanced perception and increased understanding of the water pollution problem caused by intensive pig farming and stimulated the collective search for solutions