Ranking of river systems of the northeastern slope of the Greater Caucasus according to their self-purifying ability depending on abiogenic factors

The ability of aquatic ecosystems to self-purify is closely dependent on many natural factors. The purpose of the study is to assess the self-purifying ability of surface waters for pollutants along the coastal zone of the Caspian Sea (in the territory of Azerbaijan) under the influence of abiogenic factors - climatic, hydrodynamic, hydro chemical, etc. The system analysis revealed a general pattern : in general, the self-purifying ability of river systems along the Caspian coastal zone increases in the direction from south to north. In order to preserve water quality in river systems, it is important to develop a set of measures to protect biodiversity in these coastal terrestrial ecosystems and water catchments (watersheds) on the northeastern slope of the Greater Caucasus.