An estimation method of soil freeze-thaw erosion in the Qinghai–Tibet Plateau

Abstract

Limited by natural and scientific factors, freeze-thaw (FT) erosion, as a typical erosion process along with wind and water erosion, has not been given enough attention. In this paper, we introduce microwave remote sensing techniques to establish an estimation model of FT erosion. The model includes seven factors: the annual FT cycle days, the average diurnal FT phase-changed water content, average annual precipitation, topographic relief, aspect, annual temperature range and vegetation coverage. The results show that on the whole Qinghai–Tibet Plateau scale, the average intensity of FT erosion belongs to the category of moderate erosion. The spatial extent of the FT erosion region is 163.96 (104) km2, accounting for 63.46 % of the study region. Exhibiting spatial heterogeneity, the distribution of the FT erosion shows an upward trend where the erosion intensity increases from slight erosion in the northwestern region to severe erosion in the southeastern part of the study region. Because of the vast extent of the Qinghai–Tibet Plateau, the dominant impact factors for the FT cycle differ over the area. The mid-west plateau is mainly influenced by the annual FT cycle days, average diurnal phase-changed water content and temperature. The southern and southeastern zones are influenced by precipitation, topographic relief and aspect. During the study period, regions which dominated by alpine shrubs were the most severely affected by FT erosion. The results show significance for the understanding of the mechanism and occurrence of FT erosion and therefore provide a scientific basis for the prevention and treatment of FT erosion.