Water appropriation and ecosystem stewardship in the Baja Desert

Abstract

The UNESCO San Francisco Rock Paintings polygon within El Vizcaino Biosphere Reserve in the Baja California Peninsula derives its moisture from the North American monsoon. There, ranchers have depended on the desert since the 18th century. More recently, the desert has depended on the environmental stewardship of the ranchers who have allayed mining exploitation and archaeological looting. Using a Rapid Assessment Procedure (RAP), climate data, and geographical information, sustainability was assessed and foreseeable risks identified, on behalf of the Reserve. The results showed that the costs of stewardship were in terms of water appropriation and livestock herbivory. The socio-ecological system also faced hydrological risks derived from runoff, high evaporation rates and climate change. Additional risks stemmed from the increasing global demand for minerals, including hydrocarbons, found in the Reserve. These external drivers could substantially alter the attitudes of the ranchers or the land tenure. Land abandonment might become possible as children and women seemed to out-migrate from the polygon. Solutions were identified based on the supply and demand for water and should enhance resilience via watershed management and in-ranch water appropriate technologies.