Dam-Induced Global Surface Water Dynamics: Introducing the Global Dam Tracker

Abstract:

Dams are a major source of electricity globally, with hydropower generating 16 percent of the world's total electricity and 71 percent of all renewable electricity in 2016. Many developing countries possess great untapped hydropower potential, and proponents of dams praise them as a source of low-carbon electricity, estimated to reduce annual emissions by about 2.8 billion tons of carbon dioxide equivalent. However, dams also come with concentrated costs, such as fragmenting river ecosystems, triggering ecological hazards, and displacing at least 40 million people globally. Worldwide, there are around 58,000 large dams (more than 15 meters in height). Their reservoirs have an estimated cumulative storage capacity of around 8000 km³ and cover approximately 305,723 km², which is equivalent to an increase of Earths’ natural terrestrial freshwater surface by more than 7%. Despite the social and environmental concerns associated with dams and their reservoirs, few studies have quantified the impact of dams on temporal global surface water changes using granular geospatial data. In this project, we draw on an original global dam database with detailed attribute information, the Global Dam Tracker (GDAT), and employ state-of-the-art geospatial analysis to quantify dam-induced global surface water changes over the past 35 years.