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
Faba fix for corn's nitrogen need
11.04.2018 | American Society of Agronomy
Wheat research discovery yields genetic secrets that could shape future crops
09.04.2018 | John Innes Centre
At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.
Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...
Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.
Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
25.04.2018 | Physics and Astronomy
25.04.2018 | Physics and Astronomy
25.04.2018 | Information Technology