松嫩沙地末次冰期以来降水量和干燥度的时空变化

THE TIME-SPACE CHANGE OF PRECIPITATIONAND ARIDITY DEGREE OF SONGNEN SANDLAND SINCE LAST GLACIAL AGE

根据表土花粉与降水量和干燥度相关的原理,选择对降水量和干燥度有指示意义的花粉的百分含量,运用多元线性回归分析的方法,推算了松嫩沙地末次冰期以来的古降水量和古干燥度,并在此基础上推测了沙地的环境演化过程.

Songnen sandland lying in the middle of northeast China is in the continental monsoon climatic region of transitional belt between semi-humid and semi-arid temperate zone. It is the first-grade susceptible belt of environmental evolution in China.Since the last glacial age, the nature environment of Songnen sandland have undergone complex evolution process. Based on the principle that vegetation is related to precipitation and aridity degree, using pluralistic linear regression analysis, the authors calculated quantitatively the precipitetion and aridity degree of Songnen sandland since the last glacial age, and drew the change curves of precipitation and aridity degree in different periods, and 1. 1 - 1. 2 isogram of aridity degree. Since the last glacial age Songnen sandland underwent 5 periods of high precipitation and low aridity degree. And the east boundary of the sandland in different periods have also been estimeted.