Wind erosion has become one of the major causes of land degradation on the Qinghai-Tibet Plateau (QTP). Assessing wind erosion dynamics is critical to forecast wind erosion and formulate desertification control strategies. In this study, the spatial and temporal variations in wind erosion on the QTP from 1980 to 2015 were evaluated by the revised wind erosion equation (RWEQ). Furthermore, the relative contributions of climate change and human activities to wind erosion were analysed to identify the drivers. The results showed that wind erosion intensity on the QTP increased continuously from southeast to northwest. Areas with moderate or high soil erosion intensity (>25 t∙hm2∙a-1), accounting for 53.48% of the region, were mainly distributed on the western and northern parts of the plateau. The mean annual soil wind erosion modulus (SWEM) of the total region during 1980-2015 was 32.08 t∙hm2∙a-1, with an obvious decline at a rate of approximately 0.14 t∙hm2∙a-1 in this period. However, 9.99% of the study area showed a relatively significant increase, and these areas were mostly located in the northwestern part of the region. Climate change, especially variation in wind speed, was the dominant factor that affected wind erosion over the whole plateau, whereas the impacts of human activities such as grazing and ecological restoration policies and programmes were comparatively small and usually more localized.
Vulnerability assessment has become a critical issue and an important approach for regional sustainable development. The Qinghai Province, located in the northeastern part of the Qinghai-Tibet Plateau, suffers a severe grassland degradation caused by climate change and human activities. The degradation constrains the development of local animal husbandry and further affects the vulnerability of social system. In this study, based on the vulnerability assessment framework of exposure-sensitivity-adaptability, two index systems were established including ecological and social aspects. The entropy weight method was used to determine the index weight. The dynamic changes of the ecological vulnerability and social vulnerability of Qinghai province were assessed from 1995 to 2015. Results indicated that ecological vulnerability in Qinghai province increased from eastern part to the west, and decreased from northern to southern part, while social vulnerability showed an opposite trend. Key ecologically fragile areas were mainly located in the Qaidam Basin and western Three-River Headwaters Region (TRHR), while key social vulnerability areas were mainly distributed in the Qilian Mountains and eastern Qinghai province. The overall ecological vulnerability showed a decreasing trend through time, but increased in several local areas. Social vulnerability dropped significantly, especially in the eastern part of Qinghai province. The results will help to identify key vulnerable areas of Qinghai province and provide references for the ecological protection and restoration and the formulation of ecosystem management policies.