Environment Changed Information Research Which Have Been Recorded By Muneng Nur Sediment, Lower Stream Of Heihe River

The enclosed or semi-enclosed lake's sediment records, which is a sensitive indicator of climate and environmental changes, can provide us with plenty of high resolution information. And the lake's sediment have many characteristics such as continuity, sensitivity and high resolution, so they take an unchangeable advantage compared to other natural records at the aspects of the reconstruction of various short-time-scale environmental sequence. Muneng nur Lake is a small scaled tail-lake of Black River which lies in Ejina Oasis. Its sediment has recorded the environmental change process of the Ejina Oasis since late Holocene. Our research is focus on the sediment of the Muneng nur-B. As proxies of climate change,magnetic susceptibility, the content of carbonate, grain size and TOC are used in the paper.Though these proxies ,we analysed black river downstream region tail-lake to evolve process, inquiried into the Northwest dry region weather to change of drive factor. Meanwhile ,in making reference to the foundation of the history cultural heritage and study of ancient relics data, we also researched the relation between mankind's activity and the weather varieties. All of these tasks are helpful for us with understanding dry region ecosystem of Black River downstream environment of turning into process and drive mechanism, predicting the future weather changes of the region. At the same time, we can get some useful lessons on the ecosystem construction and continuable development of Ejina oasis as well. This research mainly obtained several results as follows:1.There are 9 changes of the water level of the Muneng nur lake totally during 1544-1960. We can divided the 416 years into 9 stages with higher 5 water levels of stages which represent larger flux and relative humid clamite periods of the blacj river. Oppositely ,there are lower 4 water levels of stages, indicate the flux is smaller, the weather is drier and the oasis shrink back. The variety trend of Ejina is consistend with Huhehaote city in climate changes, however, the durative opposite humid period of Ejina is much shorter than that of Huhehaote city.2.Seen from the total time length, there are just 134 years to be moister in the 416 years which is represented by Muneng nur-B. Yet the drier year totally has 282 years. This expresses the climate of the area gives priority to long-term drought , which is accompanied by short-term rainness.3.The comprehensive analysis aimed at the magnet susceptibility,carbonate content,grain degree and the organic carbon content show us that the variety trend of of the magnet susceptibility and the carbonate content presents better negative relativity between the 71-156 cms, which indicates the water level variety of Muneng nur lake in this period is mainly influenced by climate changes.But the variety trend of the magnet susceptibility is more confusion from the 71...