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sur le développement des zones arides et semi-arides

Titre : Study on Wind Erosion Characteristics of Different Underlying Surfaces and Sand Control and Fixation Benefit of Vegetation of Cele in Xinjiang

Auteur : 关含笑

Grade : Master 2022

Université : Kashi University

Résumé partiel
Wind erosion is one of the main sources to desertification and dust storms,which seriously affects the regional ecological security.Vegetation can fix sand through rhizomes,and change the structure of wind and sand flow in the process of wind erosion,so as to play the role in benefits of sand reduction.In this paper,through field observation test,the wind erosion law of different underlying surfaces and different wind conditions,the effect of vegetation sand fixation and erosion reduction and its influencing factors in Cele County,southern margin of the Taklimakan Desert were analyzed,the conclusions are as follows :（1）According to the analysis of wind-blown sand flow structure on different underlying surfaces,gravel cover has an impact on near-surface sediment transport,and the closer to the surface,the more obvious reduction of sediment transport.The relative difference of sediment transport proportion at different heights of gravel surface was small,followed by soil-rock mixed surface,and the difference of bare sand surface was the largest.Transport of wind sand reduced the content of fine particles in wind erosion with gravel underlying surface,the composition and structure of wind erosion particles were continuously coarsening.Different underlying surface material conditions lead to significant differences in wind-blown sand flow movement and mechanical properties.With the increase of gravel coverage,aerodynamic roughness increases accordingly,and the resistance of surface airflow increases.（2）The wind speed profiles of different underlying surfaces showed that with the increase of height,the increase of wind speed gradually decreased.The gravel cover on the underlying surface has an impact on the jump sand,caused differences in wind energy density.The sand carrying capacity of wind at different heights was related to the change of wind speed,and the proportion of sand transport generated by wind speed at 12.62 m/s above 15 cm from the ground was gradually different from that under other wind speed conditions.Under the speed of 7.47 m/s,8.39 m/s and 9.53 m/s,the variation of sediment transport conforms to the exponential function distribution,while the wind speed was 6.57 m/s,it conforms to the power function distribution,and the linear function distribution is 12.62 m/ s.

Mots clés : Wind erosion ;Sediment discharge ;Benefit of Vegetation Prevention ;Amount of sediment reduction ;Affecting factors ;

Présentation (CNKI)