River dam impacts on biogeochemical cycling

Taylor Maavara, Qiuwen Chen, Kimberly Van Meter, Lee E. Brown, Jianyun Zhang, Jinren Ni, Christiane Zarfl

Research output: Contribution to journalReview articlepeer-review

95 Citations (SciVal)

Abstract

The increased use of hydropower is currently driving the greatest surge in global dam construction since the mid-20th century, meaning that most major rivers on Earth are now dammed. Dams impede the flow of essential nutrients, including carbon, phosphorus, nitrogen and silicon, along river networks, leading to enhanced nutrient transformation and elimination. Increased nutrient retention via sedimentation or gaseous elimination in dammed reservoirs influences downstream terrestrial and coastal environments. Reservoirs can also become hotspots for greenhouse gas emission, potentially impacting how ‘green’ hydropower is compared with fossil-fuel burning. In this Review, we discuss how damming changes nutrient biogeochemistry along river networks, as well as its broader environmental consequences. The influences of construction and management practices on nutrient elimination, the emission of greenhouse gases and potential remobilization of legacy nutrients are also examined. We further consider how regulating hydraulic residence time and environmental flows (or e-flows) can be used in planning and operation from dam conception to deconstruction.

Original languageEnglish (US)
Pages (from-to)103-116
Number of pages14
JournalNature Reviews Earth and Environment
Volume1
Issue number2
DOIs
StatePublished - Feb 2020

All Science Journal Classification (ASJC) codes

  • Atmospheric Science
  • Earth-Surface Processes
  • Nature and Landscape Conservation
  • Pollution

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