Method. Environmental assessment of the surface water of the Guyva River was carried out using the system of classification of standards for the assessment of surface water quality of Ukraine. On the basis of common environmental criteria, the methodology makes it possible to compare the quality of water at different sites of water bodies, in water bodies of different regions. The calculation of the ecological assessment of water quality was carried out within three blocks: block of salt composition (І1), block of trophic-saprobiological (ecological-sanitary) indicators (І2) and block of indicators of content of specific substances of toxic action (І3). The results are presented in the form of a combined environmental assessment based on the final conclusions of the three blocks and based on the calculation of the integrated environmental index (IE).
Results. omprehensive studies on changing the water quality of the Guyva River were conducted within the Zhytomyr region during 2016-2017. The water quality of the river according to the final values of the integral indicators of water quality of the three blocks varies within the II and III quality classes. The total environmental indices (IEs) for the mean and worst indices are 2,9 and 3,1 respectively. In general, the water quality along the main channel of the Guyva River within the Zhytomyr region corresponds to the second class, 3 categories, 3(2) subcategories according to the average quality indicators (in the state of "good" with a slope to "very good", in terms of purity bias to "clean") and 3 subcategories by worst performance (good for good, clean enough). The total values of the integral surface water quality indicators of the Guyva River indicate their contamination by trophic-saprobiological components.
Scientific novelty. For the first time, on the basis of analytical studies and stock materials, an ecological assessment of the surface waters of the Guyva River within the Zhytomyr region was carried out by three blocks of indicators: salt composition, trophic-saprobiological indicators and specific toxic substances. The integral ecological index is determined. The trends of pollutants accumulation in the surface waters of the River Guyva have been established.
Practical significance. The conducted researches allowed to analyze and evaluate the ecological status of the surface waters of the Guyva River within the Zhytomyr region, which will allow to establish ecological standards of water quality and on this basis to determine the main directions for improvement of water resources and to substantiate the system of recommendations aimed at improving the ecological status of the studied basin.
ENVIRONMENTAL ASSESSMENT OF SURFACE WATER QUALITY OF THE BASIN OF THE INGULETS RIVER IN THE MIDDLE REACHES
