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 Smart Data Transformation – Surfing the Big Wave
02.12.2016 | Fraunhofer-Institut für Angewandte Informationstechnik FIT

nachricht Climate change could outpace EPA Lake Champlain protections
18.11.2016 | University of Vermont

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: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>