Estimation of current denudation rate of the mountains based on the suspended sediment runoff of the rivers (the Tien Shan, the Pamir-Alai, the Caucasus, and the Alps as an example)

Abstract

Annual denudation rates were calculated using data on the suspended sediments runoff module of the rivers. These rates vary widely: from less than 0.005 to more than 1.75 mm/year in the Caucasus, Pamir-Alai and Alps; from 0.002 to 0.4 mm/year in the Tien Shan. The most significant factors of denudation cutting of the mountains are topography, climate and composition of rocks. The maximum rates of denudation (more than 1 mm/year) occur in the highest and most humid parts of the mountains (Western Alps, Western Caucasus, etc.). The minimum values of annual denudation rate (less than 0.1 mm/year) are observed on the lower mountain slopes with little rainfall and with resistant to denudation sediments (eastern slopes of the Lesser Caucasus, the interior of the Tien Shan, etc.). Vegetation and human activities can both enhance and suppress exogenous processes and thus the denudation rate. In all these mountains tectonic uplift prevails over the denudation.