Hydrochemical distribution patterns in stream waters, Trøndelag, central Norway

• Published in: The Science of the total environment 2001-02, Vol.267 (1), p.1-21
• Main Authors: Banks, David, Sæther, Ola Magne, Ryghaug, Per, Reimann, Clemens
• Format: Article
• Language: English
• Subjects: Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental Monitoring; Exact sciences and technology; Geochemical map; Geochemistry; Hydrochemical trend; Hydrogen-Ion Concentration; Hydrology; Hydrology. Hydrogeology; Mineralogy; Norway; Pollution, environment geology; Silicates; Stream waters; Water - chemistry; Water geochemistry; Water Pollutants, Chemical - analysis; Water Supply
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/S0048-9697(00)00605-7

A regional geochemical sampling program of stream waters has been carried out in the Nord-Trøndelag region of central Norway. This area has hitherto been little affected by regional anthropogenic sources of pollution. Hydrochemical trends appear to be dominated by interplay of two main factors: (i) input of sea salts via marine aerosols in precipitation: and (ii) geological sources (mineral weathering). Factor (i) results in a predominance of Na-Cl waters near the coast, and may also be partially responsible (via proton displacement from soil ion-exchange sites by marine cations) for lower pH values in near-coastal waters. Further inland, the importance of marine salts decreases and waters become dominantly Ca-(Na)-HCO 3. Sub-regional anomalies in geochemical maps for, e.g. nitrate and copper may indicate anthropogenic sources for these parameters from agriculture or mining activities.