Positive Ion Contained in Tamarix Cone Sedimentary Veins and Climatic and Environmental Change in Southern Region of Taklimakan Desert

Based on the research on Tamarix cone sedimentary veins in three different places which are Andier Ancient City, Andier Meadow, and Damagou Township in the southern region of the Taklimakan Desert, the relationship between the characteristics of the positive ion content in Tamarix fallen leaves and climatic change during the past 400 years is systematically analyzed. The results show: the order of four kinds of positive ion content’s change range in three sampling sites is Ca²⁺> K⁺> Mg²⁺> Na⁺. The correlation coefficient between Ca²⁺ content and the total positive ion content is higher, which indicates that Ca²⁺ content or the total positive ion content can reflect the change trends. There is an inverse correlation between positive ion content in Tamarix fallen leaves and the local temperature. According to the change of positive ion content, the climate in the southern region of the Taklimakan Desert can be divided into cold and warm periods during the past 400 years, among which the period of 1590-1691 is warm period, of 1692-1896 is cold period (warm fluctuations are 1799-1808,1825-1829,1878-1881,1887-1891), of 1897-2010 is warm period (cold fluctuations are 1939-1941,1992-1998); Precipitation has a poor correlation with the positive ion content; There is a better correspondence between the changes of positive ion content and the regional flood events. This research provides a kind of research method for the environmental evolution in the southern region of the Taklimakan Desert,and it is of great help to environmental change research of the arid desert regions. It has further perfected the feasibility of using positive ion content in Tamarix cone sedimentary veins to reveal the environmental change, and fills up the blank of high resolution climatic change during the past 400 years in the southern region of the Taklimakan Desert.