The Spatial Variation of Aerodynamic Parameters and Wind Erosion Potential in Southwestern Tarim Basin from Shifting Desert to Oasis

The southwestern Tarim Basin of China is a primary wind erosion damage and environmental degradation region characterized by shifting sand dunes, semi-shifting sand dunes, fixed sand dunes and oasis farmlands. To determine their relative susceptibility to wind erosion under different land cover types, wind velocity profiles were measured and used to determine friction velocity (u*) and aerodynamic roughness (z(0)) of the four land cover types throughout the wind erosion season of 2010-2012. The erodible particles contents of surface soil mass were analyzed. The u* averaged 0.33 ms(-1), 0.44 ms(-1), 0.61 ms(-1) and 0.81 ms(-1), while z(0) averaged 0.39 mm, 13.58 mm, 39.51 mm and 310.8 mm for the shifting sand dunes, semi-shifting sand dunes, fixed sand dunes and oasis farmlands, respectively. The results showed that u* and z(0) were both correlated with surface roughness properties of the underlying vegetation condition and z(0) decreases with increasing wind speed due to the near surface plant roughness properties and wind flow. The erodible particles content were 56.92%, 60.17%, 65.80% and 74.56% for the shifting sand dunes, semi-shifting sand dunes, fixed sand dunes and oasis farmlands, respectively. These results indicate that though the oasis farmlands have the largest erodible particles content but with the greatest u* and z(0), the dynamic wind conditions were not usually able to achieve by causing the dust emission. In contrast, the shifting sand dunes have the greatest potential for wind erosion due to lowest u* and z(0).