From Community Evidence to Desertification Policy: Participatory Water Management and Local Knowledge in Brazil’s Semi-arid Region

Desertification and drought are reducing water availability across Brazil’s semi-arid region, undermining livelihoods and exposing limitations in current water governance. More equitable and durable responses require approaches that combine scientific analysis with traditional ecological knowledge and participatory water-management practices. This study presents a collaborative project co-developed with Quilombola and Indigenous communities in a region severely affected by water scarcity and land degradation. Using an intersectional participatory framework, we integrate hydrological modelling and spatial analysis with qualitative fieldwork to identify policy gaps, constraints, and opportunities to strengthen water security. We mapped priority areas for water conservation and restoration and identified locations where desertification processes are advanced, especially in zones with an aridity index below 0.65. We also present preliminary results from focus groups and participatory workshops that surface community-defined water risks, locally grounded indicators of degradation, and feasible adaptation and restoration strategies. These insights are being directly mobilised in parallel policy discussions, creating a feedback loop between community evidence and decision-making. Specifically, our preliminary findings are feeding into the design of a state-level policy to combat desertification by supporting participatory planning, targeting priority areas, and strengthening implementation mechanisms that reflect both local realities and scientific evidence. This work contributes to Brazil’s National Action Plan to Combat Desertification and Mitigate the Effects of Drought and supports UNCCD and SDG targets related to water security and sustainable land management.