Troubled waters at the frontier: Mapping forest-dependent people's access to surface water in the Dry Chaco

Abstract

Several studies have demonstrated that agricultural commodity frontier expansion impacts local populations’ access to terrestrial natural resources, yet few have addressed the expansion’s impacts specifically on access to surface water for forest-dependent smallholders. We develop a novel approach to fill this gap, and apply it to the Pilcomayo River Basin, in Argentina, Paraguay, and Bolivia. We 1) generate a typology of surface water bodies, 2) map distances forest-dependent people travel to access them, and 3) show how agricultural expansion between 2000 and 2018 affected these travel distances. Our results show that the most useful water bodies for livelihoods such as livestock herding were the least widely distributed in the region. The average travel distance to all surface water bodies increased by 14%, translating to over two hours per day of additional travel time for cattle herds, or three for goat herds. Settlements in Paraguay experienced the greatest increase in distance, by an average of 1.36 km. Reduced water access also correlated with settlement disappearance, as settlements that disappeared during the study period experienced significantly greater increases in distance than others. Our findings highlight the need for interventions to prevent further ecological marginalization of forest-dependent people.