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

3.3. LAKE KIVIJARVI Lake Kivijarvi (watershed of the River Kemijoki) is located at a distance of 305 km to the south-west of the town of Nickel and 29 km to the east of the settlement of Muonio in Finland. It is a small (area of the lake 186.92 ha), shallow-water (maximum depth 9.0 m) oval-shaped lake of glacial origin. The maximum length is 2.4 km and maxi­ mum width 1.1 km. The point of maxi­ mum depth is located in the central part of the lake. According to the landscape type, the watershed area belongs to the forest zone with heights of upto 419 m (Korkea-Ki- virova fell). The lake shores are high, and covered by shrubs and pine forest. 3.3.1. Hydrochemistry The water of the lake is neutral with a low mean total mineralization (14.8 mg/l) and a low mean alkalinity (130 |ieq/l).The lake has low concentra­ tions of base cations and anions, with calcium (average 2.5 mg/l) and bicarbo­ nate (average 8.0 mg/l) predominating. The P and N concentrations ofwater are the main criteria used in assessing the development of water eutrophica- tion. The concentrations and relation­ ships between the species of P and N vary according to the season, and the dy­ namics is to a greater extent determined by the level of production and, conse­ quently, the trophicity of the water body. The concentrations of total P and total N during the vegetation period reach 13 |ig/l and 250 [ig/1, respectively. According to the concentrations of mineral nutrients, the lake is classified as mesotrophic. The lake also has col­ our values and organic matter (up to 7.4 mg/l) and Fe concentrations (mean 780 |ig/l) typical of small water bodies in the region. During high water periods in the summer the concentrations of P 0 43 and N 0 3", which determine the lake productivity, are low. Color of water, deg. 65 65-65 NH4, цд/І 6 5-8 N03, цд/І 2 2-2 N, цд/І 250 220-280 P, мд/і 12 11-13 Fe, мд/І 780 770-790 Hydrochemical jroperties —.11 6.98 pH 6.97-6.99 Electrical conductivity, 20 mS/cm 20-21 Ca, mg/l 25 2.5-2.5 Mg, mg/l 06 0 . 6 - 0.6 Na, mg/l 1 2 1 . 2 - 1.2 K, mg/l 02 0.2-0.3 HC03, mg/l M 7.9-8.1 S04, mg/l 18 1 . 8 - 1.8 Cl, mg/l 05 0.5-0.5 Total mineralization, mg/l 14.8 14.7-15.0 Alkalinity, мед/1 130 129-132 Physico-geographical characteristics Watershed River Ounasjoki— River Kemijoki Latitude 67°58.638' Lonqitude 24°19.438' Height above sea level, m 267.7 Height above sea level, m 2.4 Maximum length, km 1.1 Maximum width, km 9.0 Area, hectares 186.924 Watershed area, km 2 7.219 Study period 2005 Catalogue o f Lakes in the Russian, Finnish and Norwegian BorderArea