Water filtration is an ecosystem function that enables access to cleaner water with less costs to water purification. Soils filtrate solid impurities from the runoff waters before entering back to water bodies or ground water reservoirs.
There are 6 020 classified groundwater areas in Finland which cover altogether an area of 13 300 km2. About 0–50% of annual precipitation is filtrated into groundwater. Vegetation, topography, granule size, layer structure of the soil and soil density all affect the groundwater volume. Most of the groundwater is generated during snow melting season and autumn rains. Largest high-quality groundwater deposits are situated in areas of eskers, terminal moraines and glacial river and river bank depositions that are coarse-grained and porous in structure. About 61% of the communal water supply is taken from groundwater deposits.
Maaperän pohjavesi. Geologian tutkimuskeskus. [In Finnish]
Talousvesi. Vesilaitosyhdistys (VVY). [In Finnish]
- Updated (20.01.2015)