Wind tunnel experiment on wind erosion of different soil surfaces in Qinghai-Tibet Plateau,China
,2, Ping Yan1
,2, Yao Qian1
,2, Miao Dong1
,2, Xiaonan Meng1
1State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing, China, 2Academy of Disaster Reduction and Emergency Management, Beijing Normal University, Beijing, China
Wind erosion has become a very serious environmental problem in arid and semiarid regions, also in Qinghai-Tibet Plateau, China. But the research on wind erosion in the Qinghai-Tibet Plateau is still rather weak. In this paper, based on the field investigations, we chose 17 different types of undisturbed soil in Qinghai-Tibet Plateau to conduct wind tunnel experiments, analyzed the wind erosion characteristics of the main soil surfaces and discussed the relationship between wind erosion rate and desertification degree to provide theoretical foundation for establishing sandy desertification index system and preventing and controlling of soil erosion. Wind tunnel experiment indicated that there were significant differences in wind erosion characteristics of different types of land surface. The threshold velocity was negatively related to the average particle size and positively correlated with the soil hardness. Most of the average wind erosion rate increased with wind speed but some of them intermittently increased with wind speed. According to average wind erosion rate, the intensity of wind erosion can be divided into five categories as >200、50～200、10～50、2～10、0.5～2、<0.5 g•m-2•s- 1,which were correspond to severe, intensive, moderate, mild and slight wind erosion respectively. And it can be further improved to establishing sandy desertification index system. Degraded grassland and playa among the different types of surfaces with higher dust flux as suspension into the upper atmosphere, may be the main source of dust storms in Qinghai-Tibet Plateau.