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依据野外观测数据,研究了科尔沁沙地沙丘、草甸两种地貌类型区土壤含水率以及地下水位对降雨的响应规律。结果表明:(1)沙丘表层0-20cm的土壤含水率在降雨开始后20min就基本能够达到最大值,此后开始减小,水分不断向下运移,最大可引起次表层(20-60cm)土壤水分发生一定变化,但不会引起剖面更深层位土壤含水率的变化;2009年丰水期沙丘地下水位变动趋势为总体抬升,但受到降雨及其他因素影响产生一定波动,但影响幅度较小;(2)就草甸地而言,即使是很小的降雨量也会引起草甸地较深层位土壤含水率的变化,雨后草甸地土壤剖面受降雨影响最大的层位是20-40cm,而同时段40-80cm处的土壤含水率波动较小。草甸地地下水位波动大于沙丘,较小的降水也会引起草甸地地下水位的迅速上升,上升持续时间短,而后立即转入下降,属陡涨陡落型。研究成果对沙地的生态保护具有一定的指导作用。
According to the field observation data, the law of soil moisture content and the response of groundwater level to rainfall in the two types of landscapes of sand dunes and meadow in Horqin sandy land were studied. The results showed that: (1) The soil moisture content of 0-20cm in the surface layer of sand dune reached the maximum at 20min after the rainfall began, then began to decrease, and the water continued to migrate downwards. The maximum soil subsidence (20-60cm) The change of water content did not lead to the change of soil moisture content in the deeper layers of the profile; the trend of groundwater level in dune during the wet season in 2009 was generally uplifted, but fluctuated slightly due to rainfall and other factors, but the influence range was small; (2) In the meadows, even a small amount of rainfall can cause changes in the soil moisture content in the deeper layers of the meadow. After rain, the soil layers in the meadows that are most affected by rainfall are 20-40 cm , While the same period of 40-80cm at the soil moisture content fluctuations less. The groundwater table in the meadow fluctuates more than the sand dunes. The smaller precipitation also causes the groundwater table in the meadow to rise rapidly, and the duration of the rise is short. The research results have certain guidance to the ecological protection of sandy land.