Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sierra Nevada freshwater runoff could drop 26 percent by 2100, UC study finds

02.09.2014

The cause? Increased high-elevation plant growth fueled by climate warming

Freshwater runoff from the Sierra Nevada may decrease by as much as one-quarter by 2100 due to climate warming on the high slopes, according to scientists at UC Irvine and UC Merced.

Accelerated plant growth at higher elevations caused by increasing temperatures would trigger more water absorption and evaporation, accounting for the projected runoff declines, the researchers add.

A diminished river flow will only add to the burden of providing resources to the thirsty farms and homes that rely on it. The state is currently experiencing a severe drought, and some reservoirs and groundwater levels are at all-time lows.

The study findings appear this week in the early online edition of Proceedings of the National Academy of Sciences.

"Scientists have recognized for a while that something like this was possible, but no one had been able to quantify whether it could be a big effect," said UCI professor of Earth system science Michael L. Goulden of the decreased runoff. "It's clear that this could be a big effect of climate warming and that water managers need to recognize and plan for the possibility of increased water losses from forest evaporation."

According to the researchers, runoff from mountain ranges is vulnerable to temperature hikes that lengthen growing seasons and result in more vegetation growth at high elevations. Snow-dominated mountain forests that are currently dormant in winter with cold temperatures have lower vegetative density and less evapotranspiration than downslope forests in the snow-rain transition zone, which have year-round growing seasons. Evapotranspiration is the combination of water evaporation from land and the loss of water through plant-leaf transpiration.

Goulden and UC Merced's Roger C. Bales investigated the potential influence of a warming climate on evapotranspiration in the Kings River Basin in California's Sierra Nevada and found resulting changes in the amount of freshwater mountain runoff available to serve surrounding communities.

They gauged water vapor emission rates and combined those measurements with remote sensing imagery to determine relationships among elevation, climate and evapotranspiration. According to the data, freshwater mountain runoff is highly sensitive to expanded vegetation growth.

The authors found that greater vegetation density at higher elevations in the Kings basin with the 4.1 degrees Celsius warming projected by climate models for 2100 could boost basin evapotranspiration by as much as 28 percent, with a corresponding 26 percent decrease in river flow.

Further, the relationships among evapotranspiration, temperature and vegetation density were similar across a broader area of the Sierra Nevada, suggesting that the impact of climate change on evapotranspiration and freshwater availability could be widespread.

"Most people have heard about the giant forests around Yosemite and Sequoia national parks, but these areas have not been a focus of this type of research. Understanding of Sierran hydrology has improved recently with the National Science Foundation's Critical Zone Observatory, and data collected there allowed us to look at the problem from several perspectives," Goulden said. "All of our analyses pointed in the same direction: An upslope expansion of forest with warming would cause a large increase in evaporative water loss and lead to reduced water availability."

###

Bales is a professor of engineering and director of the Sierra Nevada Research Institute at UC Merced. The research was supported by the NSF, through the Southern Sierra Critical Zone Observatory (EAR-0725097) and a major research instrumentation grant (EAR-0619947), and by the U.S. Department of Energy's Terrestrial Ecosystem Science program.

About the University of California, Irvine: Founded in 1965, UCI is ranked first among U.S. universities under 50 years old by the London-based Times Higher Education and is the youngest member of the prestigious Association of American Universities. The campus has produced three Nobel laureates and is known for its academic achievement, premier research, innovation and anteater mascot. Currently under the leadership of interim Chancellor Howard Gillman, UCI has more than 28,000 students and offers 192 degree programs. Located in one of the world's safest and most economically vibrant communities, it's Orange County's second-largest employer, contributing $4.3 billion annually to the local economy.

Media access: UC Irvine maintains an online directory of faculty available as experts to the media at today.uci.edu/resources/experts.php. Radio programs/stations may, for a fee, use an on-campus ISDN line to interview UC Irvine faculty and experts, subject to availability and university approval. For more UC Irvine news, visit news.uci.edu. Additional resources for journalists may be found at communications.uci.edu/for-journalists.

Laura Rico | Eurek Alert!
Further information:
http://www.uci.edu

More articles from Studies and Analyses:

nachricht Researchers simplify tiny structures' construction drip by drip
12.11.2018 | Princeton University, Engineering School

nachricht Mandibular movement monitoring may help improve oral sleep apnea devices
06.11.2018 | Elsevier

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Purdue cancer identity technology makes it easier to find a tumor's 'address'

16.11.2018 | Health and Medicine

Good preparation is half the digestion

16.11.2018 | Life Sciences

Microscope measures muscle weakness

16.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>