Editorial: Hydropower: From ecology to policy

Abstract

Hydropower generation through river exploitation is widely considered a renewable and clean energy 15 source because of absent or negligible greenhouse emissions into the atmosphere. However, previous 16 studies have demonstrated that hydropower plants and related structures often affect river ecosystems 17 and their biota in several ways (Kondolf et al., 2014;Grill et al., 2019). The ecological impacts can 18 occur during all the phases associated with these manufacts, from the construction to their mode of 19 operation, and are mainly driven by changes in the physical habitat (e.g. water temperature, sediment 20 grain size, water depth and velocity, discharge fluctuations and dewatering). Quantifying the 21 magnitude of such alterations on biodiversity and river processes is usually difficult and may vary 22 depending on the site-specific conditions. 23 Nations (Goal 7). This has fuelled in the last decades the proliferation of small to medium hydropower 38 plants in the mountain areas of Europe and their number is expected to increase worldwide in the next 39 future (Zarfl et al., 2015). In the light of this, quantifying the impacts of hydropower serves as a basis project to basin and regional levels. By comparing case studies from different countries, the Authors 63 provided useful insights on how to maximize all the benefits in a sustainability perspective.In