Cooperation under conflict: participatory hydrological modeling for science policy dialogues in the Aculeo Lake

Abstract

Abstract. Hydrological modeling tools can support collaborative decision processes by visually displaying hydrological systems connections, uncertainties and gaps, as well as conflicting preferences over water management strategies. Nevertheless, many challenges remain in the real application of these technical tools to successfully implement, capture, and communicate to non-experts the complexities of coupled human hydrological systems and effectively support science policy dialogues. The disappearance of a 12 km2 lake in the Aculeo basin in Chile led to increasing socio environmental conflicts over the causes and effects of the water scarcity. A traditionally WEAP based hydrological model study aiming to explore the causes of the lake desiccation, was transformed into a multiple question driven socio hydrological modeling process to help answer the diversity of questions instigating conflict. The surface aquifer hydrological model tested a subset of socially accepted management strategies under two climate change scenarios, showing that combining more low impact, but socially acceptable adaptation measures such as using the out of season irrigation surplus (March to May), improving irrigation efficiency for agriculture industry and decreasing the grass surface in new urbanizations, would allow to recover up to half the Lake water volume even under a pessimistic climate change scenario. As presented in this article, flexible approaches and research agendas could better support the exploration of synergies towards collaboration and production of useful and socially acceptable hydrological models and water management strategies.