Home – Home – Jornals – Geography and Natural Resources 2021 number 2

This article proposes the approach to assessing the nonadditive property of the aquatic ecosystem (ecological well-being) of small streams. As the criteria for assessing ecological well-being, we used the stability of a water body to external influences, the water quality, the production of a resource link, the biota diversity, the rate of self-purification of the aquatic ecosystem, the trophic status were criteria for assessing environmental well-being. Some of these characteristics are estimated in terms of multi-criteria. The following indicators were used in the assessment: the catchment area of the river, the average annual water discharge, the duration of the low-water phase, the fluctuation of the water level, the biomass of forage benthos, the stability of the channel, the specific combinatorial water pollution index, the Shannon diversity index, etc. Five classes of environmental well-being were identified on a scale from 0 to 1: low, below medium, medium, above medium and high. On the basis of field data, a model-classification of the assessment of environmental well-being was tested for six streams of Leningrad oblast and the city of St. Petersburg. A calculation of the integral index of ecological well-being showed the absence of small rivers with high ecological well-being. Most of the stations used in the study belong to the category with well-being below medium. Only a few stations located in the sections of the streams at a distance from large settlements are categorized as medium and above medium.