To irrigate the 6.5 million hectares of land of the Mayo River Valley, Sonora, Mexico uses nearly 77% of its water. Sonora is home to seven indigenous groups, with over 110,000 indigenous people living on their ancestral, though largely reduced, territories. The Mayo River Valley is the ancestral land of the Mayo (Yoreme). The 65,000 Mayo who live along the river provide the region with its cultural identity. However, official plans for river water focus on high yield, high value crops, and urban water use. The result is a hydrological crisis for indigenous people in the river valley. Over 90% of those interviewed indicate the climate is hotter and dryer than in the past, consistent with climatologists who report a significant increase in temperatures, with a decrease frequency of frost and an increase in the number of frost-free days in the region. Climatological models indicate that future rainfall will be more varied with longer periods between precipitation events, but more intense rains when they occur. We conclude that local knowledge systems provide an opportunity to understand the impact of climate change at the local level and to develop a system of evaluation of the impact of change in the local hydrological system based on local epistemologies.

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Agrarian and hydrological territory

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Mayo River Irrigation District

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Figure 3.docx

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Climate perception and access to water