1 / 10

LAKE Monitoring & Modelisation S Jacquet, B Vinçon-Leite & B Tassin

LAKE Monitoring & Modelisation S Jacquet, B Vinçon-Leite & B Tassin. Monitoring of « our lakes ». Venoge. Aubonne. Léman. SHL2. Rhône. Dranse. Lake. Rivers. Frequency of sampling. Month (winter) Bi-weekly. Weekly 3 per day. Equipment s. Boats, Nets, Seabird Secchi disk, ….

vance
Download Presentation

LAKE Monitoring & Modelisation S Jacquet, B Vinçon-Leite & B Tassin

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. LAKE Monitoring & Modelisation S Jacquet, B Vinçon-Leite & B Tassin

  2. Monitoring of « our lakes » Venoge Aubonne Léman SHL2 Rhône Dranse Lake Rivers Frequency of sampling Month (winter) Bi-weekly Weekly 3 per day Equipments Boats, Nets, Seabird Secchi disk, … Automatic water sampler Measurements Macro- & micronutrients, TOC Chl a, PP,Transp, zoopk, microphytopk,nanophytopk, O2, pH, temp, cond, fluo Macro- & micronutrients, cond, DOC Sampling 18 – 20 depths 50 cm from bottom Long-term time series for many parameters

  3. Lake Bourget B Frequency of sampling Bi-weekly Effort Every 6-7 years Next time : 2003 Lake + rivers Equipments Boats, Nets, Seabird Secchi disk, … Measurements Macro- & micronutrients, TOC transp, zoopk, microphytopk, O2, pH, temp, cond, fluo, light… Sampling 7 – 11 depths Long-term time series for a few parameters

  4. * C * * * B B2 B1 * * * M M2 M1 * A * * T BL * P Monitoring of P. rubescens An improved approach since April 2002 Sampling B + Spatial variability of algal distribution

  5. Modelisation The lake Bourget water quality model Vinçon-Leite and co-authors (1991, 95, 98) initially developed for Lake Léman adapted and completed for lake Bourget (Tassin and co-authors) AIM deep lake functioning to predict the future changes of Lake Bourget water quality to assess the efficiency eutrophication control programs 1-D vertical model, dispersive type Coupling of thermal & biogeochemical models Empirical formulation for dispersion coefficients Incrementing time = 3 h

  6. Modelisation Conceptual representation of lake Bourget model • P phosphorus • N nitrogen • DIC dissolved inorganic carbon • Si silicium • Zoo zooplankton • Bac bacteria • PB bacterial production • PP primary production • R respiration • Ex excretion • M mortality • Pred predation • Relar release from sediment

  7. Modelisation Good agreement between modeling and physical data = First necessary step

  8. Données Régression linéaire Modèle Modelisation Winter mixing 1981 – 1998 Evolution of dissolved P stock (in tons) Model vs. data better understanding of biogeochemical processes intervening in P evolution co-sedimentation of P and calcite role of calcite in sedimentation process of algae role of iron hydroxides in Bourget hypolimnion

  9. Modelisation such predictive 1-D model on the management side are still scarce; however They can help in the planning of the field survey & in the understanding of the meteo impacts on the lake Exemple of application Algal successions 1D physical model Water column stability Temperature Mixing time scale Algal successions ? Light climate meteorology

  10. Modelisation of P. rubescens behavior in lake Bourget  Towards a predictive model 1-D biogeochemical model (2002 : cyanobacterial growth) (2003 : integration of meteo data) TEST & EXPLOITATION & 3-D hydrodynamical model (2002 : construction) (2003 : scenario definition) TEST & EXPLOITATION  COUPLING 3-D map of this cyanobacterial bloom  Alert system

More Related