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坝上地区为最典型的生态环境脆弱带。通过对10 ka 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) 10~6.9 ka B.P.为冰后期升温时期,湖泊处于高水位;(2) 6.9~3.0 ka B.P.为大暖期,发育了4层古土壤,其间有4~5次小的冷湿或冷干的波动,5.4 ka B.P.湖泊开始逐渐萎缩,到2.1 ka B.P.时水位下降了2.7 m;(3) 3.0 ka B.P.以后总的趋势是向干旱变化,为暖干与冷干环境。
Bashang area is the most typical ecological environment vulnerable zone. The results show that (1) the period of 10 ~ 6.9 ka BP is the period of post-ice warming and the lake is at high water level; (2) the period of 6.9 ~ 3.0 ka BP is During the warm-warm period, 4 layers of paleosol were developed, with 4 or 5 small cold or wet fluctuations during the period. The lakes started to shrink gradually after 5.4 ka BP, and the water level dropped by 2.7 m at 2.1 ka BP. (3) 3.0 After ka BP, the general trend is to change to arid, warm and dry environment.