【作者】 彭国栋；

【导师】 喻光明；

【作者基本信息】 华中师范大学 ， 自然地理学， 2012， 硕士

【摘要】 气候变化和沙漠化问题已经成为二十一世纪自然科学的热点话题之一,良好的环境条件能够为人类的发展提供稳定的生存保障。古尔班通古特沙漠位于我国新疆北部盆地中央,是由温带固定/半固定沙丘组成的封闭沙漠。全球气候对其影响被削弱,局部气候对其影响明显加强,通过对这种类型的沙漠和气候进行研究,能够极大地拓宽互馈机制理论,为地区的环境规划和沙漠治理措施导向奠定科学的理论基础。本文通过中国气象科学数据共享服务网,选取新疆奇台站、克拉玛依站、富蕴站在1981-2010年期间的温度、降水、风速三组日数据,分别输入到Excel表格中进行统计量处理,并利用沙丘移动指数模型和S干旱指数模型计算有关指数值,再输入到MATLAB数学软件中导出模拟函数和统计量变化折线图,最后利用SPSS分析软件对结果做相关分析,利用功率谱分析有关的周期。另一方面,本文选取GLCF/landsat imagery数据网上的5,4,3波段TM影像,利用ERDAS软件截取合适的经纬度范围作为目标图像边界,对影像做监督分类。并利用栅格数据元,对比三个地区1990年和2006年沙丘面积和表面属性的变化规律,检验沙丘移动指数规律的可信度。本文的主要研究结果和结论有：(1)古尔班通古特边缘沙漠的温度地域差异不断缩小,降水地域差异不断加大,地区风沙活动减弱,地表蒸发对该地区的影响不大,这种气候地域规律可能更多的和人为因素有关。研究表明,1984年前后为气候恶劣期,1997年前后为沙漠化严重期,特殊时期的气候异常主要发生于气候转型期。(2)1981年以来,该地区的气候逐渐从干冷转向暖湿,相应的沙漠化进程逐渐开始逆转。沙漠西缘气候与沙漠化相关系数达到了0.812,南缘为0.764,北缘为0.658,均达到显著相关标准。(3)该地区的气候变化和沙漠化过程出现多次波动,沙漠化状况和气候波动的幅度和方向有关。负向气候波动、较小的正向气候波动对沙丘迁移的影响不明显,而沙漠化对较大的正向气候波动可能极为敏感。(4)该地区不同位置的气候与沙漠化波动频率普遍存在4年或者准4年的波动周期,可能和亚欧大陆冬季雪盖面积的异常有关。(5)该沙漠的沙丘迁移表现为沙丘面积的变化和沙丘表面植被比例的变化,研究表明：西缘沙丘面积明显减少,北缘和南缘绿化面积有所增加,沙漠的自然条件有所好转。本文共分五部分：第一部分为引言,主要介绍“气候变化与沙漠化互馈机制”的研究背景、国内外研究进展以及本文的思路与技术路线。第二部分为理论基础,介绍各种气候因子对气候和沙丘的影响,阐述沙漠气候系统下的互馈机制理论。第三部分为模型和应用,重点介绍本文所采用的模型和方法。第四部分为实证研究,以古尔班通古特边缘沙漠为例,探究该地区气候变化规律、沙丘迁移状况并讨论它们之间的相互关系。第五部分为结论,重点提炼古尔班通古特沙漠“气候变化与沙漠化互馈机制“的特殊规律,从而达到扩充互馈理论的目的。更多还原

【Abstract】 Climate change and desertification has become one of the hot topics of the the natural sciences in the twenty-first century, and good environmental conditions for human development can provide a stable life-support system. Gurbantunggut desert located in the central basin of northern Xinjiang, which is a closed desert composed of temperate fixed/semi-fixed sand dunes. Global climate and its impact is weakened, and the local climate and its impacts is significantly strengthened. through research this type of desert can greatly broaden the crossfeed mechanism theory of the desert and the climate, laid the scientific theoretical foundation for the areas of environmental planning and policy-oriented.In this article, through China’s meteorological science data sharing service network, we select three groups of data include temperature, precipitation, and wind speed from qitai station, kelamayi station and fuyun station in xinjiang during1981-2010respectively, then input into Excel for statistics processing, and use the dunes mobile index model and S drought index model to calculate the exponent value, then enter to mathematical software-MATLAB for deriving the simulation function and statistical change line charts, finally, making use of SPSS software to do the correlation analysis, using of the power spectrum to analysis relevant cycle at the same time. On the other hand, this paper selects TM image of5,4,3band which appropriate coordinates range is intercepted as a target image boundary to do the Supervise-Classification from GLCF/landsat imagery data network using of ERDAS. And by calculating original grid data, we compared the variation of sand dunes acreage and sand dunes surface properties of three areas to inspect the credibility of the rule of sand dunes mobile index in1990and2006.The main research results and conclusions are as follows:(1) The temperature regional difference of the edge of the Gurbantunggut desert was shrinking, at the same time, the precipitation regional difference was increasing and the district sandstorm activity has begun to ease, the impact of surface evaporation to the region was insignificance, the regional of climate law may be more related to human factors. meanwhile, It is the bad climate for period around1984and the severe period for desertification around1997, special period of climate anomalie mainly happen to climate Transformation Period.(2) since1981, the region’s climate get dry and cool from damp and hot, the desertification of corresponding process has begun to reverse. In the west margin Desert,the correlation coefficient of climate and desertification reached0.812, corresponding to the southern was0.764, the north was0.658, which were all up to significant related standards.(3) the region’s climate change and the process of desertification appear Many fluctuations, desertification status related to range and direction of climate fluctuation.negative climate fluctuation, smaller positive climate fluctuation which impact on sand dunes migration are not obvious, and the desertification for larger positive climate fluctuation may be more sensitive.(4) the different positions of the climate and desertification fluctuating frequencies Widespread4years or allowed4year cycle that related to abnormal area of winter-snow-cover in Eurasian land.(5) the migration of the sand dunes in this desert performance for the variation of sand dunes area and the proportion of surface vegetation, research shows that:west margin of sand dunes area reduce significantly, along with the northern and southern of offerested areas increased, so the natural condition of this desert had improved.This paper is divided into five parts:The first part is introduction, mainly introducing research background of "climate change and mutual feedback mechanism of desertification", research progress, thinking and technical line of this paper.The second part is the theoretical basis, and describes the influence of various climate factor on climate and the sand dunes, in order to expound the desert climate system of mutual feedback mechanism theory;The third part is the model and application, which is mainly introducing the model and the method;The fourth part is empirical research, exploring the region climate and sand dunes change rule and discussing the relationship between their migration in Gurbantunggut edge desert;The fifth part is the conclusion, key refining the special law of Gurbantunggut desert "climate change and mutual feedback mechanism of desertification", so as to expanse achieve the mutual feedback theory.更多还原