Integrated 3D modelling of water circulation and dynamics of phytoplankton:The effects of a planned reservoir

• Main Authors: Inkala, Arto, Hellsten, Seppo, Heikkinen, M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 1998
• Subjects: Kemijoki; Porttipahta; Kemijärvi; Northern Finland
• Online Access: https://cris.vtt.fi/en/publications/36765e77-0d88-426d-bcbf-a7514df52936

The FINNALGA model has been used to assess the effects of a planned reservoir, Vuotos, on a downstream lake, Kemijärvi, in northern Finland. The model is based on 3D calculations of water currents and water quality. The simulation results are compared with the measurements and the effects of Vuotos on the present situation are assessed. The assessments on increased nutrient inputs are based on the earlier experiences of an existing similar reservoir at Porttipahta. Many scenarios were made to obtain as versatile assessment as possible. According to the model simulations, the average concentrations of algal biomass will increase by 20-60 %, while the maximum concentrations will double during the first years of the reservoir Vuotos. The effects will be most appeared in the northern part of the lake, near the estuary of Kemijoki. In the eastern parts of the lake the effects will be smaller, because it is not on the through flow route of Kemijoki.