摘要
坝上地区为最典型的生态环境脆弱带。通过对１０ｋａ以来形成的古沙丘，古土壤剖面和湖泊变化的分析，结果表明，（１）１０－６．９ｋａＢ．Ｐ．为泳后期升温时期，湖泊处于高水位；（２）６．９～３．０ｋａＢ．Ｐ．为大暖期，发育了４层古土壤，其同有４～５次小的冷湿皮动，５．４ｋａＢ。．Ｐ湖派生开始逐渐萎缩，到２．１ｋａＢ．Ｐ．时水位下降了２．７ｍ，（３）３．０ｋａＢ．Ｐ．以后总的趋势是向干埋变化。
The Bashang region is a typical vulnerable eco-environmental zone. The analysis of paleodunes, paleosol profiles, and lake changes taking place during the last ten thousands years indicates that 10~6.9 ka B.P. was a post-glacial temperature-increasing stage, in which lakes had their high water level. 6.9~3.0 ka B.P. was a large warm stage, and during which four paleosol layers were developed and climate fluctuation has assumed 4~5 small cold-humid and cold-dry alternations. Since 5.4 ka B.P., the lakes tended to gradually shrink; and by 2.1 ka B.P. water level has fallen by 2.7 m. Since 3.0 ka B.P., a general trend of the region was to change into a warm-dry and cold-dry environment.
出处
《土壤与环境》
CSCD
2000年第2期87-90,共4页
Soil and Environmental Sciences
基金
国家自然科学基金项目(49872094和49572168)
