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Relief of the Ükök catchment

The Ükök catchment is devided in three main parts. The gentle intermountain basin areas are located at an altitude around 1800 to 1900 m a.s.l. At its south border, the basin has a depth of around two to four kilometers, with a decreasing sediment thickness towards north [4]. The areas around the Chüy River are characterised by alluvial terraces [5]. In southern direction they are followed by steep alluvial-proluvial slope foods [5]. Differenciated from this area by a sharpe, the lower mountainous part between 2000 and 3000 ma.s.l. is characterized by erosional-gravitational processes.

The "V"-shaped Ükök valley is roughly running in east-western direction, with strongly divergent south and north exposed slopes. Erosional processes are more intensive on south-facing slopes, because they are steeper. Furthermore, due to the higher insolation, higher evaporation and lower soil moisture slow plant growth. Hence, the sparse vegetation cover is not protecting the soils from erosion. This valley asymmetry is determining the soils and plant composition in the whole Ükök catchment.

Several glacial landforms are coming across in the Ükök catchment; erosive forms as ridges, cols and "U"-shaped glacial valleys and accumulative forms, mainly lateral and ground moraines [3]. Also periglacial processes can be observed, foremost solifluction lobes, beginning at an altitude of 3000 m a.s.l.,with a higher quantity on northern slopes. The periglazial zone is located in a zone between 3000 and 3500 m a.s.l., the glazial zone above 3500 m a.s.l. Due to fluctuations in temperature and moisture, processes of chemical and physical weathering are active. Especially in steep areas, slope forming processes and mass movements occur [3] and the related accumulative landforms like talus cones are visible.