Water quality characteristics of forest rivers around Lake Biwa

• Published in: Water science and technology 2001-01, Vol.43 (5), p.183-192
• Main Authors: FUJII, S, SOMIYA, I, NAGARE, H, SERIZAWA, S
• Format: Article
• Language: English
• Subjects: Applied sciences; Calcium; Chlorides; Cluster analysis; Continental surface waters; Earth sciences; Earth, ocean, space; Ecosystem; Engineering and environment geology. Geothermics; Environmental Monitoring; Eutrophication; Exact sciences and technology; Forests; Geography; Geological Phenomena; Geology; Hydrology; Hydrology. Hydrogeology; Japan, Biwa L; Lakes; Magnesium; Natural water pollution; Nitrogen - metabolism; Organic Chemicals - metabolism; Organic matter; Plants; Pollution; Pollution, environment geology; Purification; Rivers; Silica; Silicon dioxide; Species; Streams; Surveys; Trees; Water Movements; Water Pollution - analysis; Water purification; Water quality; Water treatment and pollution; Watersheds
• ISSN: 0273-1223; 1996-9732
• DOI: 10.2166/wst.2001.0282

Forest river surveys were carried out at upper streams of several rivers in the Lake Biwa watershed to understand the water quality characteristics of the rivers, and to find out their relationships with forest features such as geographical, geological and vegetational data. The results showed: (1) Forests have some purification functions for nitrogen and organic matter, but become sources for most of ionic species. (2) Main mineral species in forest rivers are Ca2+, Mg2+ and Na+, HCO3-, CO3(2-), Cl-, SO4(2-) and SiO2. (3) Loading from forests was 0.4-7 kg/km2/d for TN and 0.01-0.3 kg/km2/d for TP. (4) River quality reflects the properties of each forest, and is unique to the place, especially in ionic species such as Ca2+ and Cl-. (5) A cluster analysis successfully categorized ionic components into several groups.