Movement of carbon in large U.S. rivers affected by reservoirs, finds study

Sponsored by


RESTON, VA, June 19, 2014 -- A new study conducted by U.S. Geological Survey (USGS) scientists, and published in the Journal of Geophysical Research – Biogeosciences, has found that a combination of climate and human activities (diversion and reservoirs) controls the movement of carbon in two large western river basins, the Colorado and the Missouri Rivers.

Different downstream patterns were found between the two river systems. The amount of carbon steadily increased down the Missouri River from headwaters to its confluence with the Mississippi River but decreased in the lower Colorado River. The differences were attributed to less precipitation, greater evaporation and the diversion of water for human activities on the Colorado River.

For upstream/headwater sites on both rivers, carbon fluxes varied along with seasonal precipitation and temperature changes. There was also greater variability in the amount of carbon at upstream sites, likely because of seasonal inputs of organic material to the rivers. Reservoirs disrupted the connection between the watershed and the river, causing carbon amounts downstream of dams to be less variable in time and less responsive to seasonal temperature and precipitation changes.

The study presents estimates of changes in the amount of carbon moving down the Colorado and Missouri Rivers and provides new insights into aquatic carbon cycling in arid and semi-arid regions of the central and western U.S, where freshwater carbon cycling studies have been less common. This work is part of an ongoing effort to directly address the importance of freshwater ecosystems in the context of the broader carbon cycle. In the future, changing hydrology and warming temperatures will increase the importance of reservoirs in carbon cycling and may lead to an increase in greenhouse gas emissions that contribute to global warming, but it may also increase the amount of carbon buried in sediments.

Rivers move large amounts of carbon downstream to the oceans. Developing a better understanding of the factors that control the transport of carbon in rivers is an important component of global carbon cycling research. The study is a product of the USGS John Wesley Powell Center for Analysis and Synthesis and the USGS Land Carbon program.

See also:

"Human activities contribute to rise of dissolved solids in U.S. streams, finds study"

"American Rivers releases America’s Most Endangered Rivers of 2014 report"

###

Sponsored by

TODAY'S HEADLINES

Online Zeta Potential Measurement Provides Water Treatment Control, Cost Reduction

Online zeta potential measurements can provide real-time water quality monitoring and support effective process control under all circumstances. The value of online measurement is illustrated through the experiences of Aurora Water, which is using zeta potential at one facility as both an offline and online tool for monitoring and controlling water treatment processes.

Pacific Institute issues helpful analysis of CA water bond to better inform Nov voters

Voters on CA's November ballot will be asked whether to approve Proposition 1, the Water Quality, Supply and Infrastructure Improvement Act. As such, the Pacific Institute has released an objective new report that helps voters untangle the complexities of the water bond measure.

Research offers unique insight into monitoring groundwater at Ohio fracking sites

A new research project at the University of Cincinnati is taking a groundbreaking approach to monitoring groundwater resources near fracking sites in the state of Ohio.

EPA announces preliminary determination to regulate strontium in drinking water

EPA has announced that it has officially made a preliminary determination to regulate strontium in U.S. drinking water. Strontium is a naturally occurring element that, at elevated levels, can impact bone strength in individuals who do not consume enough calcium.

FOLLOW US ON SOCIAL MEDIA