祁连山牧坡草地空气相对湿度近地梯度变化规律初步分析

对祁连山西水林区排露沟流域牧坡草地近地空气湿度进行连续观测.结果表明:其日变化过程中,以10∶30和20∶30为分界点,以前者为起点的空气相对湿度呈上升趋势,以后者为起点则呈下降趋势;50 cm高度处空气相对湿度高于其他高度的空气相对湿度,其差值为3.3%;梯度差异性最大值出现在6∶00和12∶30;由于草地特有的小环境影响,其相对湿度最小时也达51%;空气相对湿度在降雨后为最大,之后急剧下降,进入第4 d趋于平稳.

Preliminary analysis of the near-ground gradient changes of air relative humidity on grazing meadow of the Qilian Mountains

The near-ground air relative humidity on sloping pasture of the Pailugou Valley in the Xishui forest area in the Qilian Mountains was continuously observed.The results showed that in the daily change process,the time of 10∶30 and 20∶30 were the boundary points.The air relative humidity was in a rising tendency with the former as a starting point,which was in decreasing tendency with the latter as a starting point.The air relative humidity at 50 cm height was higher than that at any other heights,and the difference value was 3.3 %.The maximum gradient differences appeared at 6∶00 and 12∶30.Because of the unique influence of the meadow microenvironment,the minimum relative humidity also reached to 51 %.There was a greatest value of air relative humidity after rain,then it sharply descended,and at the fourth day it tended to be steady.