Sandimirov S.S. Catalogue of lakes in the Russian, Finnish and Norwegian Border Area. Finland, Jyvaskyla: Kopijyva Oy, 2008.

2.11. LAKE SAMETTIVATN Lake Samettivatn (watershed of the River Paz) is located 26 km to the west of the town of Nickel. The lake is not large (the area of the lake is 2.31 km2), nor deep (maximum depth 10 m), and is close to oval shape and of glacial origin. The maximum length is 2.95 km and maximum width 1.15 km. The points of maximum depth are located in the cen­ tral part of the lake. The lake forms part of a lake-river system, and a larger stretch is located in its northern part. According to the landscape type, the watershed area belongs to the forest-tundra zone, with heights of up to 220 m. Boulder beds occur in almost all parts of the littoral zone. The lake shores are covered by shrub vegetation and pine forests. Physico-geographical characteristics Watershed River Sametti— River Paz Latitude 69°27.581' Longitude 29°38.028' Height above sea level, m 95.0 Maximum length, km 2.95 Maximum width, km 1.15 Maximum depth, m 10 Area, km 2 2.31 Watershed area, km 2 - Study period 2004-2005 2.11.1. Hydrochemistry The pH of the water in the lake is close to neutral, and the water has a low total mineralization (average 16.1 mg/l) and alkalinity (average 99 peq/1). During flood periods the pH drops slightly, i.e. oxidation processes do not develop due to the buffering capacity of the water. The lake has low concentrations of base cations and anions, with calcium (aver­ age 2.13 mg/l) and bicarbonate (average 6.0 mg/l) predominating. The annual chemical cycle of the lake is characterized by a slight reduction in the oxidizability, mineralization and pH of the water during flood periods when the amount of precipitation and inflow of humic water increase. Elevated concentrations of P and N are important criteria when estimating water eutrophication. The concentra­ tions of and relationships between spe­ cies of P and N vary according to the season and the dynamics is to a greater extent determined by the level of production and, consequently, the trophicity of the water body. The maximum concentrations of total P and total N during the vegetation period are 5 pg/l and 156 pg/l, respectively. According to the concentrations of mineral nutrients, the lake is classified as oli- gotrophic. The colour values and the organic matter (4.0 mg/l) and Fe concentrations (average 17.5 pg/l) are typical of small water bodies in the region. During flood periods in summer the concentrations of P 0 43 and N 0 3",which determine the lake productiv­ ity, are low. Hydrochemical properties pH 6.80 6 . 68 - 6.88 Electrical conductivity, 26 mS/cm 25-27 Ca, mg/l 2.13 2.09-2.19 Mg, mg/l 0.50 0.50-0.51 Na, mg/l 1.78 1.76-1.81 K, mg/l 0.37 0.37-0.38 HC03, mg/l 6Л 5.7-62 S04, mg/l 2.60 2.57-2.62 Cl, mg/l 2.70 2.64-2.76 Total mineralization, mg/l 16.1 15.9-16.3 Alkalinity, (jeq/l 99 94-102 Catalogue o f Lakes in the Russian, Finnish and Norwegian BorderArea