Oases are unique intrazonal landscapes distributed in the peripheries of desert and Gobi areas in arid and semi-arid regions of the world. In China, although oases take up approximately 5% of the total arid and semi-arid area, more than 90% of the population and 95% of social wealth are concentrated within these oases. The land is undoubtedly vital for agricultural production and economic development of oases. However, oasis is vulnerable to climate change and human activities, and thereafter various types of land degradation occur in oasis. The survival of oasis is partially determined by the evolution of desert-oasis transitional area (abbr. DOTA) characterized by fragile and unstable environments. This study reveals the function of DOTA in avoiding oasis land degradation from its aeolian environments based on the detailed wind data, in situ observation of wind-blown sand and granular characteristics of surface sediments from desert to oasis.
Results/Conclusions
Results indicate that the DOTA has buffering function in slowing down aeolian desertification in oasis. Additionally, the annual mean wind speed reduces 40.8% from desert to DOTA area but up to 92.8% from desert to oasis. The frequency of sand-laden wind, drift potential and sand transport all decrease following the section from desert to oasis while surface roughness increases. And the granular characteristics of surface sediments show that the weight percentage of coarse sand decreases but fine sand increases along the section from desert to oasis. This paper reveals that the aeolian environments are of great difference between desert and DOTA and the significant role of DOTA in protecting oasis. Integrated sand control system needs to be settled in the DOTA to strengthen its buffering function.