Morpho-climatic characteristics and soil development in Mongolia

Abstract

Mongolia's high latitude/altitude and strong continentality make its climate and vegetation, topography and soil development different from those of a typical periglacial or arid zone. The wide range of daily/annual temperatures, glaciers and permafrost means that freeze-thaw processes are very active in almost all areas, and forest/steppe landscapes develop. It is an arid environment with low precipitation, but subtropical air masses in summer can cause seasonal flooding and inundation. These features make Mongolia a region with a very different character from region to region. Zuunkharaa is characterised by relatively low temperatures/evaporation and permafrost, leading to the development of periglacial features such as ice lenses, ice wedges and hummocks, while Lun, a tributary lowland formed by summer flooding, dries up and takes on the characteristics of a deflation lake. In the Karakorum, at the junction of mountains and plains, extensive alluvium is deposited in the form of alluvial fans. In Bayanzag, strong evaporation causes solonchacks to form, but active freeze-thaw processes and winds produce a hardened surface similar to desert pavements. Mongolia's landforms and soils are the result of a combination of strong freeze-thaw processes/evaporation, surface water and wind erosion, seasonal precipitation and flooding, and the influence of permafrost.