# Characteristics of Aeolian Dune, Wind Regime and Sand Transport in Hobq Desert, China
## 5 Discussion  
Wind is the power responsible for movement of aeolian sediments, thus transport should increase with increasing wind speed. However, other factors can disrupt this simple relationship. For example, precipitation can increase vegetation cover, sand moisture content and the air's relative humidity, and all of these factors can decrease sand transport [32; 33]. Increased temperatures have the opposite effect: they increase evaporation, and thereby decrease soil cohesion. Thus, climate change will affect the formation and subsequent evolution of sand seas and sand dunes [3]. To figure out the influence of long-term climate change on sand transport, we analyzed the relationship between DP and annual precipitation and annual average temperature. The annual precipitation at Linhe station was positive correlated with DP. While, it was negative correlated with DP at the eastern part of the Hobq Desert (Figure 12a).  
Figure 11: Characteristics of annual precipitation (**a**) and annual average temperature (**b**) from 2009 to 2018 at three representative weather stations in the Hobq Desert (referring to Figure 5 for the abbreviated names of stations).  
For the annual average temperature, it had a positive correlation with DP at Baotou station (Figure 12b) and the annual average temperature at Dongsheng and Linhe stations had a negative correlation with DP. However, the relationships between DP and the annual precipitation and temperature at all the stations from 2009 to 2018 were not significant (\(p>0.05\)). Although precipitation and temperature directly restricted the species diversity, growth and development of plants, usually, the vegetation developed in dry years is difficult to produce coverage protection effect on the surface [34]. For the Hobq Desert with a large area of migratory dune, there wasno significant correlationbetween the temporal changes in DPand climate change. The modern environmental monitoring of the Maowusu Sandy Land, which is located in the south of the Hobq Desert shows that the vegetation restoration capacity of the east and west of the Maowusu Sandy Land was out of sync with the decreasing wind, decreasing anthropology activities and slightly increasing precipitation. The eastern region gives a priority response to the climate changes, while the western region depends on the continuous improvement of climatic environment [35]. This suggests that the response to climate change in the eastern and western regions of the Hobq Desert may also be out of sync. Under the condition of a better climate, the eastern region may give a priority response to the changes, solidifying the dune and gradually developing the paleosols, while the sandstorm activity in the western region may still continue, at least it did not form the environmental conditions for soil development. Meanwhile, through study on the sedimentary sequence of the strata in the Hobq Desert, it is found that the formation of aeolian sand in some sections is mainly related to the increase of available loose sand sources rather than the arid climate conditions [23].  
Figure 12: The relationships between the calculated DP and (**a**) annual precipitation (Pre) and (**b**) annual average temperature (Tem) from 2009 to 2018 at three representative weather stations in the Hobq Desert.