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题名	塔克拉玛干沙漠南缘策勒绿洲的沙尘沉降特征研究
作者	万的军
学位类别	硕士
答辩日期	2009
授予单位	中国科学院．新疆生态与地理研究所
授予地点	北京
导师	穆桂金，中科院新疆生态与地理研究所
关键词	塔克拉玛干沙漠南缘
其他题名	Study of the Characteristics of Falling-Dust in Cele Oasis at the Southern Fringe of Taklimakan Desert
学位专业	自然地理学
中文摘要	塔克拉玛干沙漠南缘是沙尘天气危害最为严重的地区之一。本文首先利用盆地南缘六个气象站近54年的沙尘天气资料，分析了南缘沙尘天气的变化特征。结果表明：近54年的沙尘天气变率较大，线性下降趋势显著；通过小波分析得出年沙尘日数的变化存在大约40年、19年、8～10年以及4年的周期，年沙尘日数的突变大体发生在20世纪60年代后期的由少到多的突变，以及80年代后期的由多到少的突变。 选择策勒绿洲为典型代表研究区，通过在绿洲的迎风西前缘、前缘向内2km、中央及后缘不同位置设置采样点，研究了绿洲尺度沙尘沉降的变化特征。结果表明： (1) 一次沙尘暴的平均降尘量高达124g?m-2，在绿洲不同位置的降尘量以绿洲前缘最多(173g?m-2)，随着向绿洲内部延伸，有逐渐减少的趋势，后缘位置最少；降尘以细砂成分为主，平均粒径偏粗，平均粒径高达74μm。绿洲西前缘位置的降尘粒径为最粗，从西前缘逐渐深入绿洲内部时，降尘粒径基本呈现变小的趋势； (2) 绿洲具有明显的沙尘沉降效应，在4-9月份，策勒绿洲内部的平均月降尘量高达334g?m-2，而在绿洲外缘仅为206g?m-2。尤其对于非尘暴的降尘量，绿洲内比外部高3.4倍；月降尘的平均粒径为70μm左右，以细砂与粉砂成分为主，粘粒含量极少，最高仅为3.75％。绿洲西前缘位置的降尘粒径基本都为最粗，从西前缘逐渐深入内部，降尘粒径基本呈变小趋势；不同高度的降尘亦有明显差异，随高度升高，降尘平均粒径逐渐变小，降尘量显著减少，而且减少幅度逐渐变小。不同位置的粒度分布曲线基本为负偏的尖峰态分布，而且由西外缘越深入绿洲内部，负偏程度越大，而各降尘样品基本为较差或一般分选。The southern margin of the Taklimakan Desert is one of the regions which are the most seriously influenced by the sand-dust weather. Firstly, based on the sand-dust weather and other meteorological data of six stations in the southern margin of Taklimakan Desert in recent 54 years, the change characteristics of sand-dust weather in recent 54 years are analyzed by using wavelet transform method. The results show that: the sand-dust weather has changed sharply and declined significantly in recent 54 years. The change of annual sand-dust days which contain about 40-year, 19-year, 8～10-year and 4-year cycle mutated at about the late 1960s and at late 1980s. Secondly, taking Cele oasis as the typical research area, though sampling the falling dust of a typical sand-dust storm and monthly falling-dust from April to September at the peak period of sand-dust weather in Cele oasis, the characteristics of falling-dust at different positions are studied by setting up sampling points at the western oasis, going inward into oasis about 2km, the center and the eastern edge. The results show: (1) the average falling dust amount is 124g?m-2, whose main component is fine sand with a coarse average grain-size about 74μm. The falling dust amount at western is the most (172.8 g?m-2), which is decreasing going inward into oasis and it is only 75.8g?m-2 at eastern edge. From western oasis to inner, the average-size of falling dust is getting smaller. (2) The Oasis has obvious effect of dust deposition. From April to September, the average monthly falling-dust amount in Cele oasis is up to 334g?m-2, and it is only 206g?m-2 at the outer edge of the oasis. Especially for non-dust storm falling-dust amount, it is 3.4 times more in oasis than at the outer edge. The main component of falling-dust, which has an coarse average grain-size about 70μm, is fine sand and silty sand with a spot of clay(the highest is only 3.75％). The monthly falling-dust amount at the center of oasis is the highest (353g?m-2), which is decreasing gradually from centre to edge of oasis in radial pattern. From western oasis to inner, the average-size of falling dust is getting smaller. Falling-dust at different height is also significant different, whose average grain-size become smaller and the amount, changing more significantly at lower, decrease gradually with height. The grain-size distribution curves of falling-dust all are leptokurtosis with negative skewed, and the more deepening into the oasis, the greater degree of negative skewed. The falling-dust samples are almost poorly or moderately sorted.
学科主题	气候学
公开日期	2010-11-12
页码	共62页
内容类型	学位论文
源URL	[http://ir.xjlas.org/handle/365004/8472]
专题	新疆生态与地理研究所_中国科学院新疆生态与地理研究所(2010年以前数据)
推荐引用方式 GB/T 7714	万的军. 塔克拉玛干沙漠南缘策勒绿洲的沙尘沉降特征研究[D]. 北京. 中国科学院．新疆生态与地理研究所. 2009.

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