TY JOUR TI Methodology of physiography zoning using machine learning: A case study of the Black Sea KW Spatial zoning KW Machine learning KW 𝑘-means clustering KW Black Sea KW Physiography zoning KW GIS KW clustering methodology JO Russian Journal of Earth Sciences AU Krivoguz, D.. PY 2020 IS 20 PB Geophysical Center of the Russian Academy of Sciences