Crack surface erosion in the gully in the Mongolia meadow.A gully is a landform created by running water, eroding sharply into soil, typically on a hillside. When the gully formation is in process, the water flow rate can be substantial, causing a significant deep cutting action into soil. Gullies resemble large ditches or small depth and width valleys. Aerial drone overhead flight flying green hill hills hilly slope grassland prairie meadow wold pasture steppe plateau ground land large valley big long elevation terrain geography topography tableland lowland plain Mongolian Siberian Siberia Central Asia. UHD 4K 3840X2160.