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sur le développement des zones arides et semi-arides

Titre : Study on the Influence of the Protective System Structure of Kubuqi Desert Oasis on Aeolian Sand Flow and Element Migration

Auteur : 陈宇鑫

Grade : Master 2022

Université : Inner Mongolia Agricultural University

Résumé partiel
The research on the influence of oasis protection system structure on Aeolian sand flow and element migration can clarify the influence of oasis protection system on wind erosion process and element migration,which is of great significance to the allocation of oasis protection system and the formulation of regional sand control projects.Taking the oasis protection system in the periphery of duguitala town on the northern edge of Kubuqi Desert as the research object,this paper observed and analyzed the mobile sand outside the protection system,the protection structure within the protection system（sand sealing and grass belt,wind and sand blocking forest and farmland protection forest）,as well as the wind sand activity and trace element migration characteristics within 0-100 cm near the surface of farmland in the oasis.The results show that :（1）The wind speed of 0-30 cm near the stratum of oasis protection system is significantly weaker than that of mobile sand,and the weakening range decreases with the increase of height.Under the condition of 11 m / s wind speed,the wind speed near the stratum of each protection structure is more than 30.6% lower than that of mobile sand,among which the reduction range of sand sealing and grass raising belt is the most prominent,76.3%.The inhibitory effects of different protection systems on near surface aeolian sand activities and aeolian sand flow activities are mainly concentrated in the height layer of 0-30 cm,and the average sediment transport rate is reduced by 88%.（2）Fine sand and medium sand account for the main part of surface sediments in mobile sandy land,sand sealing and grass raising belt,wind and sand blocking forest and farmland protective forest land,with an average content of 68.23% and 26.8% respectively,and the contents of very fine sand and silt account for only 2.27% and 2.69%.In farmland,fine sand accounts for 50.4% of surface samples,silty sand and very fine sand account for26.57% and 22.42% respectively,and medium sand only accounts for 0.7%.From flowing sandy land to farmland shelterbelt,the content of fine sand,very fine sand and silt increased relatively,and the content of medium sand decreased ;The content of silt and very fine sand in aeolian sand flow increases with the increase of height,and the content of medium sand decreases.The content of fine sand increases first and then decreases with the increase of height in flowing sand,sand sealing and grass raising belt,wind and sand blocking forest and farmland shelter forest,and decreases with the increase of height in farmland aeolian sand flow.

Mots clés : Oasis protection system ;Kubuqi Desert ;Sandstorm flow ;Grain size characteristics ;Element migration ;

Présentation (CNKI)