Satellite Data Helps Reveal Impacts of Hydroelectric Dams on Local Ecosystems

Image above: Flooding in Brazilian Amazon study site following hydroelectric complex installation taken June 28, 2022. © 2022, Planet Labs PBC. All Rights Reserved.

In Brazil, approximately 60% of the country’s electricity is powered by hydro dams. However, since the 1990s, there has been pressure on the country’s environment because of the construction of some of these large hydroelectric power systems, located in proximity to the megadiverse biome of the Amazon rainforest. The magnitude of these projects make it important for researchers and managers to assess the history of economic and environmental impacts caused by dams in the region as they look to ensure sustainable development in the future. To better understand this, researchers from the University of São Palo analyzed the area surrounding the Belo Monte Hydroelectric Complex in Volta Grande do Xingu from 2000 to 2017 to classify land use and land cover changes. Leveraging Landsat and PlanetScope data from the NICFI Satellite Data Program, their study detected notable changes in the land cover in the region. Large amounts of the forests had been converted to agro-pasture and the rivers had significant rock exposure, indicating a decrease in water overtime in the region. In other sections, the natural pattern of flooding was altered due to construction of the dam and both forested area and farms were submerged in river water. All of these environmental changes can have a significant impact local biodiversity. “A better understanding of the relationships between a dam’s construction, its operation and the resulting land-cover changes on the part of decision makers and public policy makers is essential for effective land management that promotes both economic development and a conceivable level of sustainability and environmental wholeness. Therefore, it is fundamental to make available the most suitable and straightforward methodologies and data sources, embracing even users outside the remote sensing community,” said the researchers. 

The full study can be found in Sustainability.