Know more

About cookies

What is a "cookie"?

A "cookie" is a piece of information, usually small and identified by a name, which may be sent to your browser by a website you are visiting. Your web browser will store it for a period of time, and send it back to the web server each time you log on again.

Different types of cookies are placed on the sites:

  • Cookies strictly necessary for the proper functioning of the site
  • Cookies deposited by third party sites to improve the interactivity of the site, to collect statistics

Learn more about cookies and how they work

The different types of cookies used on this site

Cookies strictly necessary for the site to function

These cookies allow the main services of the site to function optimally. You can technically block them using your browser settings but your experience on the site may be degraded.

Furthermore, you have the possibility of opposing the use of audience measurement tracers strictly necessary for the functioning and current administration of the website in the cookie management window accessible via the link located in the footer of the site.

Technical cookies

Name of the cookie

Purpose

Shelf life

CAS and PHP session cookies

Login credentials, session security

Session

Tarteaucitron

Saving your cookie consent choices

12 months

Audience measurement cookies (AT Internet)

Name of the cookie

Purpose

Shelf life

atid

Trace the visitor's route in order to establish visit statistics.

13 months

atuserid

Store the anonymous ID of the visitor who starts the first time he visits the site

13 months

atidvisitor

Identify the numbers (unique identifiers of a site) seen by the visitor and store the visitor's identifiers.

13 months

About the AT Internet audience measurement tool :

AT Internet's audience measurement tool Analytics is deployed on this site in order to obtain information on visitors' navigation and to improve its use.

The French data protection authority (CNIL) has granted an exemption to AT Internet's Web Analytics cookie. This tool is thus exempt from the collection of the Internet user's consent with regard to the deposit of analytics cookies. However, you can refuse the deposit of these cookies via the cookie management panel.

Good to know:

  • The data collected are not cross-checked with other processing operations
  • The deposited cookie is only used to produce anonymous statistics
  • The cookie does not allow the user's navigation on other sites to be tracked.

Third party cookies to improve the interactivity of the site

This site relies on certain services provided by third parties which allow :

  • to offer interactive content;
  • improve usability and facilitate the sharing of content on social networks;
  • view videos and animated presentations directly on our website;
  • protect form entries from robots;
  • monitor the performance of the site.

These third parties will collect and use your browsing data for their own purposes.

How to accept or reject cookies

When you start browsing an eZpublish site, the appearance of the "cookies" banner allows you to accept or refuse all the cookies we use. This banner will be displayed as long as you have not made a choice, even if you are browsing on another page of the site.

You can change your choices at any time by clicking on the "Cookie Management" link.

You can manage these cookies in your browser. Here are the procedures to follow: Firefox; Chrome; Explorer; Safari; Opera

For more information about the cookies we use, you can contact INRAE's Data Protection Officer by email at cil-dpo@inrae.fr or by post at :

INRAE

24, chemin de Borde Rouge -Auzeville - CS52627 31326 Castanet Tolosan cedex - France

Last update: May 2021

Menu Logo Principal ANR logo of NSFC mistea niglas leesu iEES LEMON LBE

ANSWER

Presentation

The project ANSWER in a few words

ANSWER is a French-Chinese collaborative project which focuses on the modelling and the simulation of eutrophic lake ecosystems to study the impact of anthropogenic environmental changes on the proliferation of cyanobacteria.

Worldwide the current environmental situation is preoccupying: the water needs for humans increase while the quality of the available resources is deteriorating due to pollution of various kinds and to hydric stress. In particular, the eutrophication of lentic ecosystems due to excessive inputs of nutrients (phosphorus and nitrogen) has become a major problem because it promotes cyanobacteria blooms, which disrupt the functioning and the uses of the ecosystems.

For 40 years, some measures of reduction of nutrient inputs, especially of phosphorus, have been applied in developed countries to fight against these blooms whereas a reverse tendency of increase of the nutrient loading is observed in other countries. At the same time, the temperature and the atmospheric CO2 concentration have been increasing with significant consequences on the dynamics of phytoplankton communities in lakes. All these local and global changes finally lead to significant modifications of the C/N/P ratio in ecosystems (i.e. the modification of the availability of the three major elements: C, N & P). The project ANSWER will evaluate the consequences that these variations can have on the dynamics of cyanobacterial blooms, by using modelling approaches and numerical simulations which will be based on existing and specific experiments and field data.

To represent the complexity of the functioning of lentic ecosystems, the use of 3D dynamical models, obtained by coupling hydrodynamic and ecological models, is essential. Because the development, the calibration and the simulation of such models require a wide range of skills, researchers of various fields (computer science, applied mathematics, modelling, physical limnology and microbial ecology) will work together to develop an integrative platform for lake ecosystems modelling, which will include tools of data management and knowledge representation, models and statistical methods for model calibration and validation. The models will be used for:

  1. the simulation of the short-term (weeks) impact of sudden changes of C/N/P ratio (due to weather events) on the initiation of blooms and the evolution of their spatial distribution;
  2. comparative simulations of the dynamics and the composition of phytoplankton communities during an annual cycle following the observed trends for the C/N/P ratio in France and in China;
  3. the test and optimization of control strategies whose combined impact with climate changes results in a modification of the C/N/P ratio.

The processes of recycling of organic matter by bacteria in the water column and of release of nutrients from the sediments will be studied experimentally to improve the model ability. Indeed, although these processes are considered as essential for the dynamics of cyanobacteria, they are often ignored or poorly represented in existing models.

One of the difficulties of the implementation of these modelling approaches often comes from the lack of data, or from their poor quality, which makes the validation and the calibration of the models difficult. Thanks to the diversity of the French and Chinese teams gathered in our consortium, we will have access to a rich database composed of good quality data acquired on diversified ecosystems (the large shallow Lake Taihu in China, the long and deep Villerest reservoir and the small and shallow urban Lake Champs-sur-Marne in France). The broad skills of our consortium, ranging from microbial ecology and limnology to modelling, will allow us to take into account in the construction, the validation and the analysis of the models, all the key processes involved in the ecosystem functioning.