摘要
通过对青海湖湖东沙地克土沙区不同类型沙丘地表沉积物粒度特征的水平变化和0～20 cm垂直变化的分析,可知自然固定沙丘的表层沉积物以细砂为主,其他沙丘以中砂为主,粒度参数随着地形起伏有不同的变化特征;随着深度的增加,粗颗粒逐渐增多,细颗粒逐渐减少,粒度参数随着深度的增加呈波动减小的趋势。通过比较分析,可得出人工治理措施对沙地地表环境的影响较大,能促进细颗粒物质的沉积,有效减少地表的风蚀量。
The sandy land on the eastern shore of Qinghai Lake is the biggest area in the decertified land of Qinghai Lake Basin. Some measures have been taken to prevent and control desertification in Kutu district since 2008. The article chose 4 sandy dune styles on the eastern shore of Qinghai Lake, 78 sediment samples were collected at 26 sites in 7 landform parts respectively. Then, grain-size range was determined by Malvem Mastersize 2000 laser par- ticle size analyzer in order to analyze the grain-size characteristics of horizontal change of surface sediments and vertical change with the depths from 0cm to 20 cm. It can be seen that on the surface of natural fixed dune, fine ma- terials content is 42.25%, and the dune is primarily made up of fine materials, while medium sand is widely distrib- uted on other sand dunes. The characteristics of surface deposits are medium because sorting coefficient is 0.78. Sand dunes＇ partial degree values range between 0.04 and 0.24, half-artificial fixed dunes＇ are near symmetrical, and other dunes＇ are positively partial. Peak state ranges between 0.90 and 1.50, natural fixed dune is with narrow peak state, and other dunes are in secondary peak condition. Meanwhile, the particle size parameters as the terrain of ups and downs have different characteristics of the change. The same depth, the higher the degree of sand dunes fixed, fine materials are more. Along with the change of the depth, coarse particles increase gradually, and fine parti- cles reduce. With the increase of the depth, particle size parameters decrease in the trend of fluctuations. Through the comparison of the grain-size characteristics of different types＇ sand dunes, artificial control measures have a great influence on sand surface environment, promoting fine particle depositing, and can effectively reduce the surface wind erosion.
出处
《干旱区地理》
CSCD
北大核心
2013年第2期203-211,共9页
Arid Land Geography
基金
国家科技支撑课题"青海湖流域沙漠化土地综合治理技术集成与试验示范"(2007BAC30B03)
林业公益性行业科研专项经费"青海湖周抗寒抗旱固沙植物筛选与快繁研究"(201004025)
关键词
青海湖湖东沙地
地表沉积物
粒度特征
地形
垂直变化
Sandy land in eastern shore of Qinghai Lake
Surface sediments
Grain-size characteristics
Terrain
Vertical change
