近200年来新疆安迪尔地区红柳沙包稳定氧同位素特征与环境变化

发布时间：2018-04-25 16:16

本文选题：塔克拉玛干沙漠南缘 + 安迪尔　；参考：《河北师范大学》2017年硕士论文

【摘要】：荒漠区是地球表层系统的重要组成部分,其环境演变影响着全球环境变化。塔克拉玛干沙漠是中国最大的沙漠,位于新疆南疆的塔里木盆地中心,深居内陆,远离海洋,气候类型为极端干旱的温暖带大陆性气候。这一地区红柳依靠其独特的生理结构得以存活。红柳落叶和风沙相互作用逐年累积形成的红柳沙包沉积纹层不但能够作为一种计年方式,而且可以提供近千年来环境变化的各种信息,是研究干旱区环境变化的理想载体。本文先用多种定年方法确定两个采样点中红柳沙包沉积纹层的年代,并提取沉积纹层枯枝落叶中的δ18O,运用SPSS软件进行相关性分析、回归分析,从而选取最为合适的代用指标,重建了该地区近200年的气候环境变化序列,并和已有的研究结果做对比。主要结论有:(1)通过对红柳落叶中δ18O与各月和全年的平均气温相关性分析得知:2月、9月、11月及全年平均气温与δ18O含量呈负相关。气温对红柳中δ18O含量的控制作用明显,表现为温度升高而红柳纤维中氧同位素含量降低。(2)δ18O系列与各月及全年平均最低温度呈负相关,其中δ18O与8月、11月最低气温相关性均通过信度0.05的检验。(3)δ18O与3月、6-9月相对湿度呈负相关,其中δ18O与11月的平均相对湿度相关性较为显著。在11月份δ18O和平均气温、平均最低气温的相关性都比较显著,在和平均温度、平均最低气温呈负相关时和相对湿度呈正相关。(4)在1-5月、9月、11月、12月及全年,δ18O值与总日照时数呈负相关关系。2月、8月通过信度0.05的检验。这可能是由于8月份日照时间长、相对湿度低、蒸腾作用加剧,植物吸收水分增多,有利于光合作用的进行,便于氧同位素的富集。(5)红柳落叶中δ18O序列与降水的相关性研究表明,12个月份及全年降水均未通过信度0.05的检验。但是在经过滑动平均处理后,滑动降水序列和δ18O序列相关性中通过信度0.05检验的有7个,且多数是负相关。(6)通过对红柳落叶中δ18O序列逐步回归分析可知2月日照时数、11月份平均温度是对红柳纤维素中δ18O的值影响较大的两个气候因子,可以解释红柳落叶纤维中δ18O序列33.6%的变化情况。(7)通过对安迪尔地区全年平均气温的重建,得到两个偏冷期1792-1822年,1853-1914年。两个偏暖期1823-1852年,1915-2010年。(8)通过对安迪尔地区7月份降水的重建,得到两个偏湿期1792-1821年,1846-1911年。两个偏干期1822-1845年,1912-2010年。
[Abstract]:Desert area is an important part of the surface system of the earth, and its environmental evolution affects the global environmental change. Taklimakan Desert is the largest desert in China, located in the center of Tarim Basin in southern Xinjiang. This area of red willow survived by its unique physiological structure. The sedimentary grain layer of red willow sand bag formed by the interaction of deciduous and wind-sand is not only a kind of chronological method, but also can provide various kinds of information of environmental change in recent thousand years, and it is an ideal carrier to study the environmental change in arid area. In this paper, we first use various dating methods to determine the age of sedimentary grain layer in two sampling points, and extract 未 18O from the litter of sedimentary grain layer. The correlation analysis and regression analysis are carried out by using SPSS software, so as to select the most suitable substitute index. The sequence of climate and environment change in this area was reconstructed and compared with the existing research results. The main conclusions are as follows: (1) by analyzing the correlation between 未 18O and the mean temperature in each month and year, we can conclude that the average temperature in February, September, November and the whole year is negatively correlated with 未 18O content. The effect of temperature on the 未 18O content of Salix willow was obvious, which showed that the temperature increased and the oxygen isotope content in the fiber decreased. The 未 18O series was negatively correlated with the mean minimum temperature of each month and the whole year. The correlation between 未 18O and the lowest temperature in August and November passed the test of 0.05) 未 18O was negatively correlated with the relative humidity in June-September of March, and the correlation between 未 18O and the average relative humidity in November was significant. The correlation between 未 18O and mean temperature, mean minimum temperature in November is significant. The mean minimum temperature was negatively correlated with the relative humidity in January to May, September, November, December and the whole year, the 未 18O value was negatively correlated with the total sunshine duration. In February and August, the reliability 0.05 test was passed. This may be due to the long sunshine in August, low relative humidity, intensified transpiration and increased water absorption by plants, which is conducive to photosynthesis. Studies on the correlation between 未 18O sequence and precipitation in Red Willow leaves showed that the reliability test of 0.05 was not passed in 12 months and 12 months. However, 7 of the correlation between the sliding precipitation series and 未 18O series passed the reliability 0.05 test after the moving average treatment. By stepwise regression analysis of 未 18O sequence in red willow leaves, the results showed that the average temperature in November was the two climatic factors which had a great influence on 未 18O value in red willow cellulose. It can be explained that the variation of 未 18O sequence in deciduous fiber is 33.6%.) by reconstructing the annual mean temperature in Andir region, two cold periods of 1792-1822 years from 1853 to 1914 can be obtained. Two warm periods (1823-1852 ~ 1915-2010) through the reconstruction of precipitation in July in the Andir region, two wet periods 1792-1821 (1846 ~ 1911) were obtained. Two dry periods (1822-1845) and 1912-2010.
【学位授予单位】：河北师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P597;P532

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