Nutrient study at Lake Pyhäjärvi. COST 869, Keszthely, Hungary Anne Mäkynen

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1 AQUATOXecological risk assessment model Nutrient study at Lake Pyhäjärvi COST 869, Keszthely, Hungary Anne Mäkynen

2 Background for all this.. My master thesis for Jyväskylä University, co-operation project with SYKE and Ramboll Finland Ltd. Catch_Lake 2-project ( remote sensing and measuring technology in coupling of catchment and lake models. The study lake is Pyhäjärvi in Säkylä and Eura municipal community. a joint venture project between Finnish Environment Institute (SYKE) and the Department of Radio Science and Engineering of the Helsinki University of Technology, other institutes and private companies. N Studying new ecolocigal models and their functionality. Irjanne Eurajoki Ñ ÑRAUMA Juvajoki Panelia Eurajoki Eurakoski ÑKiukainen W E S Köyliönjoki Turajärvi Eura Ñ Köyliö Kauttua Ñ Köyliönjärvi Säkylä Ñ Pyhäjärvi Pyhäjoki water field forest + others Ñ Yläne km Southwest Finland Regional Environment Centre National Land Survey of Finland Permission number 7/MYY/02

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4 AQUATOX-model.... is the latest in a long series models, starting with the aquatic ecosystem model CLEAN (Park et al. 1974). Behind that Water Act 1972 (key stone for protecting American surface waters)..can be implemented for lakes, rivers, streams, ponds, reservoirs and estuaries...considers several trophic levels including attached and planktonic algae, submerged aquatic vegetation, invertebrates and fish (forage, bottom-feeding and game fish)...can be implemented as a simple model or as a truly complex foodweb model.

5 AQUATOX-model....is intended to be used to evaluate the likelihood of past, present and future adverse effects from various stressors (toxic organic chemicals, nutrients, organic wastes, flow, sediments and temperature which can be considered individually or together...is designed to represent average daily conditions for well-mixed and stratified systems...considers lakes and reservoirs to have two vertical zones: epilimnion and hypolimnion....can be run with constant or dynamic data.. provides uncertainty analysis and sensitivity analysis

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7 Study lake, Pyhäjärvi N Surface area 154 km 2 ÑRAUMA Irjanne Eurajoki Ñ Juvajoki Panelia Eurajoki Eurakoski ÑKiukainen W E S Köyliönjoki Turajärvi Eura Ñ Köyliö Kauttua Ñ Köyliönjärvi Säkylä Ñ Pyhäjärvi Pyhäjoki Catchment area 615 km 2 Maximum length 25 km Mean depth 5,4 m Maximum depth 24 m Retention time 3-5 years water field forest + others Ñ Yläne km Southwest Finland Regional Environment Centre National Land Survey of Finland Permission number 7/MYY/02

8 Input data Constant: Wind velocity 3 m/s (no direction) Light loading (Ly/d) (use average and range) ph 7,2 Water temperature calculated on the basis of average values and range for epilimnion and hypolimnion Concentrations in inflow water (rivers): Tot P 85 µg/l, Tot N 1700 µg/l, CO 2 0,77 mg/l, Oxygen 11 mg/l as well as suspended and dissolved detritus 10 mg/l dry weight Non-point loading: Tot P 1600 g/d, th7 Tot N g/d and suspended and dissolved detritus 2262 kg/d. Dynamic: daily inflow from two main rivers (outflow is assumed to be the same as inflow) Simulation period Time step one day

9 Slide 8 th7 Miten arvioit? huttula,

10 Input data Biological data is default taken from AQUATOXlibrary. Libraries for: phytoplankton (~30) invertebrates (~40) fish (~20-30) macrophytes (4) Data can be edited. New species can be added by user. Unit for initial condition of biological data is described as a dry weight or concentration. Bluegreens

11 Simulated total phosphorus in lake water Obs data from 1 m without calibration Obs data from 20 m

12 Simulated total nitrogen in lake water Obs data from 1 m without calibration Obs data from 20 m

13 Simulated clorophyll-a in lake water without calibration

14 Impact assessment If Tot P load from rivers decreases 50 %...

15 Discussion AQUATOX can satisfactory simulate seasonal changes and peak values. Still needs improving with timing. Range of concentration is the same within observed and simulated values with both nutrients and clorophyll-a. Still needs testing in different kind of boreal lakes. Maybe smaller, more homogenous lake than Lake Pyhäjärvi. Biological aspects need to be tested more.

16 User friendly interface (Windows), very well documented user and technical manuals. Public and freely loadable from EPA s webpages. AQUATOX could be usable tool in planning work for predicting magnitude of nutrient concentration in the lake if: load will decrease/increase inflow will decrease/increase water temperature change (cooling water) etc. Master thesis is ready soon. Discussion Searching for new projects where AQUATOX could be tested. Anybody interested in testing at some other lake or river?