呼伦贝尔西部草原土壤干旱特征分析

The Soil Drought Features Analysis of the Western Grasslands in Hulunbeier

通过对呼伦贝尔西部草原草地不同时期土壤各层次水分含量的分析,揭示了半干旱草原土壤干旱特征,分析了干旱的季节分布以及不同季节水分在土壤各层次的分布特征。结果表明:20cm土层特旱发生频次较高,50cm、100cm土层中旱和轻旱发生频次较高,重旱在各层土壤发生频次均较低,各层次干旱发生频率均在55%以上;干旱的季节分布特征表现为:春季干旱开始发展,夏初干旱发展到最严重时期,秋季稍有回升,但封冻前未能够恢复到早春土壤含水量水平,土壤各层仍然维持干旱状态,预示来年春旱的可能发生;呼伦贝尔西部草原春、夏、秋三季连旱体现了半干旱草原的显著气候特征。

Through the analysis of soil moisture content at all levels in different periods of Hulunbeier western grassland,The soil drought characteristics of the semiarid grassland is revealed,The seasonal distribution of drought and characteristics of moisture in the soil levels are analysed monthly.The results showed： Particularly drought appeared often in 20cmdepth,moderate and light drought appeared often in 50cmor 100cm depth,serious drought occured with low frequency at all levels,the frequency of drought was more than 55%;The characteristics of seasonal distribution of drought expressed：Drought began to develop in spring,reached the most serious in early summer and rose again slightly in autumn,but is not to be able to restore soil moisture levels in early spring before the frozen,soil layer remains drought status, heralding spring drought may occur in the coming year;The western grasslands in Hulunbeier continuous drought in the spring,summer,autumn and three quarter reflects significantly.the climate characteristics of semi- drought ~rasslands.