Dynamics of Organic and Biogenic Matter Content in the Ob River Basin Pyshma and Kunara Rivers

Analysis of hydro/chemical data obtained by the Rosgidromet state observation network in the Ob River basin at the Pyshma and Kunara rivers in 1993–2013 has been done. Spatio-temporal changes in the ammonia/nitrite nitrogen, phosphates, organic matter, and dissolved oxygen content in these rivers’ water have been discussed. An integrated assessment of water quality has been given. In the Pyshma River upstream subjected to the Ekaterinburg agglomeration impact the water was characterized as «extremely polluted», a bit lower an insignificant improvement of water quality to the «polluted» level was registered. In the downstream the water low quality was caused not only by human impact but by the natural conditions of water quality formation at wetland as well. It was stated that in 1996–1997 the Kunara River water was characterized as «extremely polluted» while over the most of the period under consideration the quality improved to the «polluted» level. Alteration of organic and biogenic matter, zinc, copper, manganese compounds contents in the Pyshma and the Kunara rivers water has been investigated. In the many-year run the trend to phosphate and ammonia nitrogen content increase was noted in the Pyshma upstream, while ammonia and nitrite nitrogen content decrease was registered in the Pyshma and the Kunara downstream. It is recommended to take water/protective measures aimed at reduction of pollutants input to improve the water quality.