| Characteristics of soil moisture change in natural grassland and farmland in the region around Qinghai Lake |
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| DOI：10.7606/j.issn.1000-7601.2014.04.013 |
| Key Words: the region around Qinghai Lake soil moisture grassland farmland dynamic change |
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| Abstract: |
| The methods of climate tendency coefficient, climate tendency rate and coefficient of variation were adopted to analyze the interannual, interdecadal and annual dynamic changes of soil moisture content in natural grassland and farmland in the region around Qinghai Lake. The results showed that the annual variation trend of soil moisture content in natural grassland and farmland during same period was contrary. Since 1997, the annual variation of soil moisture content in 0～50 cm in farmland presented a significant or extremely significant increasing trend which ranged from 3.062%·10a-1 to 10.848%·10a-1, while that in natural grassland presented an insignificant decreasing trend whose rate was high at the middle stage and low at the early and late stage. The soil moisture content was increased at the turn of 20th and 21st century and during the years from 2004 to 2010. The decreasing trend of soil moisture content in natural grassland was remarkably reflected in the previous stage, and there was no obvious increase or decrease in recent years. The average value of soil moisture content in various depths was wholly greater than that in the previous stage, but it became small in summer when was the growth peak period of grass. The seasonal change of soil moisture content in grassland and farmland was the same. It was relatively high in spring and then became decreased obviously. The decreasing range of soil moisture content in farmland was larger than that in grassland because of cultivability loss of water. |
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