Finland’s surface water bodies – rivers, lakes and coastal waters – have been classified into different types according to their geographical and natural characteristics. Such a classification is needed to ensure that suitable qualitative goals can be defined for the various types of water body on the basis of their respective natural conditions. Important factors applied in this classification include predominant soil types in catchment areas (peat, mineral soils, clay), the size of the water body (lakes and rivers), depth and water retention span (lakes).
Key parameters applied in defining types of coastal water include salinity, the density of islands, extent of winter ice cover, depth, and rate of water exchange (prevailing current conditions), as well as information on marine fauna, applied to give the classification an ecological dimension.
River types
- Small peatland rivers
- Small rivers in regions with mineral soils
- Small rivers in regions with clay soils
- Medium-sized peatland rivers
- Medium-sized rivers in regions with mineral soils
- Medium-sized rivers in regions with clay soils
- Large peatland rivers
- Large rivers in regions with mineral soils
- Large rivers in regions with clay soils
- Very large peatland rivers
- Very large rivers in regions with mineral soils
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River typology in Finland
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© SYKE
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Link to a more detailed picture:
River_typology.pdf
Lake types
- Small and medium-sized humus-poor lakes
- Small humic lakes
- Medium-sized humic lakes
- Large humus-poor lakes
- Large humic lakes
- Humus-rich lakes
- Shallow humus-poor lakes
- Shallow humic lakes
- Shallow humus-rich lakes
- Lakes with very short water retention
- Lakes in N. Lapland
- Nutrient-rich and calcium-rich lakes
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Lake typology in Finland
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© SYKE
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Link to a more detailed picture:
Lakes_typology.pdf
Coastal water types
- Gulf of Finland inner archipelago
- Gulf of Finland outer archipelago
- Southwestern inner archipelago
- Southwestern middle archipelago
- Southwestern outer archipelago
- Bothnian Sea inner coastal waters
- Bothnian Sea outer coastal waters
- Quark inner archipelago
- Quark outer archipelago
- Bothnian Bay inner coastal waters
- Bothnian Bay outer coastal waters
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Coastal water types in Finland
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© SYKE
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Link to a more detailed picture:
Coastal waters_typology.pdf
More information:
limnologist Sari Mitikka, Finnish Environment Institute (SYKE), firstname.surname@environment.fi
Senior Researcher Pirkko Kauppila, Finnish Environment Institute (SYKE), firstname.surname@environment.fi