The Assessment of the Flood Hazard in 2016-2017 for the Ecological Condition of the Oxbow Ishimchik
This article studies the ecological condition of the oxbow Ishimchik, which is located in the city of Ishim. The oxbow twice suffered from floods in 2016 and 2017. As a result of flood discharge in 2016, the process of anthropogenic eutrophication started, which led to a rapid flowering of water and the appearance of a characteristic putrefactive odor - in other words, to a general deterioration in the quality of water.  The reservoir also experienced a severe oxygen starvation in the winter of 2016-2017. The result was a massive extinction of fish, as shown by the results of the examined specimens of the species Carassius gibelio. In these samples, there were signs of poisoning with nitrogen-containing ions: scaling, flukes, and bleeding.  The key point in this study is the suspension of the anthropogenic eutrophication process, due to the impact of the flood in 2017 on the part of the Ishim river, the cause of which was the mass melting of snow on the territory of the Republic of Kazakhstan. These flood waters contained a small amount of biogenic elements and after mixing with water in the old man Ishimchik noticeably stopped the process of anthropogenic eutrophication.