Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Study on Spatial Heterogeneity of Surface Sediment Components in Gobi

Auteur : 刘茜雅

Grade : Master 2021

Université : Inner Mongolia Agricultural University (内蒙古农业大学)

Résumé partiel
Gobi is a typical desert landscape surface in arid areas of China and the main dust source in East Asia.Wind-sand activity is the main manifestation of surface process in arid area.Under the action of long-term wind and sand,Gobi surface landscape is a homogeneous surface macroscopically,but there are obvious spatial differences in surface sediment composition,gravel cover and distribution form that Gobi surface wind sand activity presents time "intermittent" and space "discontinuous" and other characteristics.Surface heterogeneity restricts the process of Gobi wind-sand activity,and at the same time,wind-sand activity significantly affects the spatial distribution of sediment components in Gobi surface.Whether to quantitatively express this surface heterogeneity and to explore the response of wind-sand activity to it is an important problem with little research and scientific significance.Therefore,based on the full particle size distribution model and fractal theory,the composition characteristics and spatial heterogeneity of Gobi surface sediments in the west of Langshan are analyzed,and the wind and sand activities are observed on different surfaces.The results show that :（1）The grain size distribution of surface sediments in Gobi is "double peak ",which is mainly composed 0.063～0.125 mm,0.125～0.315 mm,and the sediment composition has spatiotemporal variability.The characteristics of the whole particle size distribution parameters and fractal dimension parameters are obvious : the distribution range C,μ,Dc Gobi surface sediment is 0～1000,-0.5～0.4,0.04～32,when the μ<0.11 is sandy surface,when it is gravel surface,the characteristic particle size Dc also increases with the increase of sediments’ particle size.Gobi surface sediments fractal dimension distribution range is 2.2～2.9,this kind of surface fractal dimension range is larger than desert surface

Mots clés : Surface heterogeneity ;Aeolian sand movement ;Pattern of full size distribution ;Fractal dimension ;Gobi;

Présentation (CNKI)