Utilizing sediment grain size characteristics to assess the effectiveness of clay–sand barriers in reducing aeolian erosion in Minqin desert area,China  

作　　者：SONG Dacheng ZHAO Wenzhi LI Guangyu WEI Lemin WANG Lide YANG Jingyi WU Hao MA Quanlin 

机构地区：[1]College of Forestry,Gansu Agricultural University,Lanzhou 730070,China [2]Gansu Hexi Corridor Forest Ecosystem National Research Station,Gansu Desert Control Research Institute,Lanzhou 730070,China [3]Linze Inland River Basin Research Station,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China

出　　处：《Journal of Arid Land》2024年第5期668-684,共17页干旱区科学（英文版）

基　　金：the National Natural Science Foundation of China(42230720,32160410,42167069);the Gansu Key Research and Development Program(22YF7FA078,GZTZ20240415);Gansu Province Forestry and Grassland Science and Technology Innovation Project(LCCX202303).

摘　　要：The clay–sand barriers in Minqin desert area,China,represent a pioneering windbreak and sand fixation project with a venerable history of 60 a.However,studies on evaluating the long-term effectiveness of clay–sand barriers against aeolian erosion,particularly from the perspective of surface sediment grain size,are limited and thus insufficient to ascertain the protective impact of these barriers on regional aeolian activities.This study focused on the surface sediments(topsoil of 0–3 cm depth)of clay–sand barriers in Minqin desert area to explain their erosion resistance from the perspective of surface sediment grain size.In March 2023,six clay–sand barrier sampling plots with clay–sand barriers of different deployment durations(1,5,10,20,40,and 60 a)were selected as experimental plots,and one control sampling plot was set in an adjacent mobile sandy area without sand barriers.Surface sediment samples were collected from the topsoil of each sampling plot in the study area in April 2023 and sediment grain size characteristics were analyzed.Results indicated a predominance of fine and medium sands in the surface sediments of the study area.The deployment of clay–sand barriers cultivated a fine quality in grain size composition of the regional surface sediments,increasing the average contents of very fine sand,silt,and clay by 30.82%,417.38%,and 381.52%,respectively.This trend became markedly pronounced a decade after the deployment of clay–sand barriers.The effectiveness of clay–sand barriers in erosion resistance was manifested through reduced wind velocity,the interception of sand flow,and the promotion of fine surface sediment particles.Coarser particles such as medium,coarse,and very coarse sands predominantly accumulated on the external side of the barriers,while finer particles such as fine and very fine sands concentrated in the upwind(northwest)region of the barriers.By contrast,the contents of finest particles such as silt and clay were higher in the downwind(southeast)region of the sampl

关 键 词：clay-sand barriers sediment grain size grain size distribution aeolian erosion windbreak and sand fixation Minqin desert area 

分 类 号：X171.4[环境科学与工程—环境科学]