Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Models Simulate Nitrate Dynamics in Garonne, Southwest France

07.01.2009
A new study details the first European application of two models that simulate the daily flow and dynamics of nitrogen in a watershed, which will help researchers prevent the over-enrichment of fresh, transitional, and marine waters with nitrogen, as well as understand the impacts of environmental change.

The over-enrichment of fresh, transitional, and marine waters with nitrogen (N) can lead to problems associated with eutrophication, such as a change in species composition of aquatic plants and nuisance algal blooms. In this context, dynamic models of flow and water quality are required to aid the implementation of the Water Framework Directive and to understand the impacts of environmental change.

Scientists from CNRS in Toulouse (France) and the University of Reading (U.K.) described the spatially and temporally complex flow and N dynamics of a major European watershed, the Garonne (62,700 km2) located in southwest France, using multivariate analysis before applying the linked rainfall-runoff HBV and the Integrated Catchment Model of Nitrogen (INCA-N) models to simulate daily flow and N dynamics.

This is the first application of the linked HBV and INCA-N models to a major European river system commensurate with the largest basins to be managed under the Water Framework Directive. Results from the study were published in the November-December 2008 issue of the Journal of Environmental Quality.

The spatial and temporal dynamics in the stream water NO3¨CN concentrations in the Garonne watershed were first described and related to variations in climate, land management, and effluent point-sources using multivariate statistics (PCA, RDA).

Building on this, INCA-N simulations were in accordance with expected flow and seasonal N patterns. In the low and mid reaches of the Garonne, the NO3-N concentrations exhibited a clear seasonal pattern with a peak concentration coinciding with fertilizer applications; that is, results highlighted that 75% of the NO3-N river load in the lowlands came from arable farming. In the upper reaches, climate controls on flow were the most important in determining the NO3-N concentrations which exhibited dilution patterns during high spring flows.

This study reinforces the interest of using semi-distributed models that represent key hydrological pathways, the spatial variations in inputs to land cover types, and a representation of the terrestrial and aquatic biochemical cycles. Thus, semi-distributed models can be used successfully to simulate the seasonal and decadal flow and water quality dynamics from mountainous headwaters to the lowlands in the largest European catchments, at large spatial (>300 km2) and temporal (¡Ý monthly) scales using available national datasets.

The full article is available for no charge for 30 days following the date of this summary. View the abstract at http://jeq.scijournals.org/cgi/content/abstract/37/6/2155.

The Journal of Environmental Quality, http://jeq.scijournals.org is a peer-reviewed, international journal of environmental quality in natural and agricultural ecosystems published six times a year by the American Society of Agronomy (ASA), Crop Science Society of America (CSSA), and the Soil Science Society of America (SSSA). The Journal of Environmental Quality covers various aspects of anthropogenic impacts on the environment, including terrestrial, atmospheric, and aquatic systems.

The American Society of Agronomy (ASA) www.agronomy.org, is a scientific society helping its 8,000+ members advance the disciplines and practices of agronomy by supporting professional growth and science policy initiatives, and by providing quality, research-based publications and a variety of member services.

Sara Uttech | Newswise Science News
Further information:
http://www.agronomy.org

More articles from Agricultural and Forestry Science:

nachricht Researchers discover natural product that could lead to new class of commercial herbicide
16.07.2018 | UCLA Samueli School of Engineering

nachricht Advance warning system via cell phone app: Avoiding extreme weather damage in agriculture
12.07.2018 | Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e.V.

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Subaru Telescope helps pinpoint origin of ultra-high energy neutrino

16.07.2018 | Physics and Astronomy

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018 | Life Sciences

New research calculates capacity of North American forests to sequester carbon

16.07.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>