The evolution of gullies in steppe and forest-steppe landscapes of the Minusinskaya intermountain depression, Siberia: a case study in the central part of the Krasnoyarsk water reservoir

Abstract

Gullies are extensive within steppe and forest-steppe landscapes of areas of the Altai-Sayan highlands. We studied gully erosion features in the Minusinsk intermountain depression, Siberia, to understand how they form, estimate the rate of formation, and assess exogenous processes influencing gully development. Morphology and genesis of gully systems in the central part of the Krasnoyarsk basin were analyzed, and regional environmental factors, as preconditions of gullying, were quantified. We applied the calculation model of potential development of gully size for the first time for this territory, and determined gully system growth rates in steppe and forest-steppe landscapes. Results show that gullying potential is characterized by large differences in landscape and morphological conditions in each drainage. In some cases, the maximum possible gully length reaches and exceeds watershed limits. Gully growth ranges from 0.1–7 m/year in length and 0.3–1.5 m/year in depth. Complex interactions of geological and landscape-climatic factors cause heterogeneity among erosion processes in space and time, resulting in gully systems that differ in genesis and morphology. We mapped the potential threat of gullying and intensity of development of existing gully systems, using the complex estimation of environmental factors favorable for gully development, and mathematical and geoinformation methods.