Dams Pose a Critical Threat to Rivers in Brazil’s Cerrado Hotspot

Abstract

Hydropower dams are touted as one of the cleanest forms of energy production, yet they are associated with severe environmental impacts on both the physical structure and functioning of river ecosystems. The threat is particularly acute in the Brazilian Cerrado—a biodiverse savanna region, spanning over 2 million km2, that concentrates the headwaters of several critical South American watersheds. Our study analyzed the current distribution of large and small hydroelectric plants in the Cerrado and focused on understanding their effect on land use changes. We also propose a Dam Saturation Index (DSI) to help spur more integrated planning for this region. Results indicate that the Cerrado river basins contains 116 (30%) of Brazil’s large hydroelectric plants and 352 (36%) of its small hydroelectric plants. Moreover, these plants spurred significant land use changes within a 5-km buffer of the dams, with over 2255 km2 of native vegetation cleared by 2000 and an additional 379 km2 in the ensuing 20 years, could reach ~1000 km2. Based on the historical anthropization process in the Brazilian savannas, we expect new crops, pastures, and urban equipment to be incorporated into this landscape, with different impact loads.

Evapotranspiration Measurements in Pasture Classes, Crops, and Native Cerrado Based on Sensors Embodied on Uavs

“…In Brazil, it is estimated that of the total water expenditure for human activities, a percentage of 69% is destined to agriculture, a value very close to the world average (70%) (Christofidis, 2001). The Cerrado, the second largest biome in South America (originally occupying 2 million km 2 of Brazilian territory) plays a unique role in the continent's water dynamics, housing the springs of twelve of the country's main hydrographic regions (Ferreira, et al, 2022). Centrally located and quite extensive, this biome is responsible for up to 80% of energy production (MMA, 2014) and approximately 50% of grain and meat production in Brazil (Queiroz, 2009).…”