石羊河尾闾青土湖表层土壤粒度空间分布特征OA北大核心CSTPCD

[Objective]The aims of this study are to reveal the characteristics of spatial distribution of soil grain size in Qingtu Lake at the end of Shiyang River,and to provide theoretical basis for ecological restoration in this region.[Methods]Sampling lines were set up in the northwest,east and southeast directions of the lake area.Soil samples at a depth of 0-20 cm were collected to compare and analyze the parameter characteristics of particle composition and particle size distribution curves in different areas around Qingtu Lake.[Results](1)The particle size composition of the surface soil of Qingtu Lake is mainly composed of fine sand(26.26％～84.97％),with fine sand being the main particle size in the northwest direction(26.26％～66.62％),followed by silt(4.23％～46.35％).The particle size composition of the surface soil in the east and southeast directions is mainly composed of fine sand(43.41％～86.30％),followed by extremely fine sand(1.86％～29.60％).There are differences in contents between different sample lines and the same particle size.(2)The surface soil particles in the research area are generally coarse and poorly sorted,with a positive skewness and a sharp and narrow kurtosis.The spatial distribution of particle size parameters shows that the average particle size of the surface soil in the northwest direction is finer than that in other directions,with poor sorting ability and more positive skewness,with a peak value smaller than that in the east direction.The average particle size of the surface soil in the east and southeast directions is relatively consistent,significantly coarser,with medium and good sorting properties,both of which are nearly symmetrical,and the kurtosis is narrow and medium.(3)The average distribution curve of soil grain size frequency shows a bimodal pattern in northwest direction,and a unimodal pattern in due east and southeast direction.The cumulative distribution curve of particle size reflects that the wind and sand activities in the southeast direction is more frequent and intense than those in the due east and northwest directions.(4)Through sedimentary environment discrimination,it can be concluded that the northwest direction is mainly lacustrine sedimentation,while the due east and southeast are mainly eolian sedimentation.[Conclusion]The soil formation process and arid and windy environmental conditions affect the basic characteristics of the soil in Qingtu Lake.The soil environment in this area is improved by ecological water transport to form water surface.