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为了揭示腾格里沙漠沙层含水量和水分运移及平衡等科学问题,对甘肃民勤和宁夏中卫不同沙丘进行了含水量研究。结果显示,腾格里沙漠南缘沙层含水量空间变化明显,在垂向上分层清楚,水平方向上流动沙丘的含水量高于半固定和固定沙丘,沙漠东南缘沙层含水量明显高于西南缘。甘肃民勤沙层含水量高值层段出现在剖面中上部;宁夏中卫毛管水带之上沙层含水量较高,指示沙层水分来自大气降水。研究区沙层水分主要以薄膜水的形式存在,在降水较多的沙漠东南缘出现了沙漠区极少出现的高含量薄膜水。该区沙层水分具正平衡特点,属于沙层水理性质决定的沙漠地区特殊的水分正平衡,这能够较好地解释极端干旱的沙漠区湖泊较多和地下水资源较为丰富的原因。论文还提出了研究区水分运移的两种模式。
In order to reveal the scientific issues such as the water content and water transport and balance in sand layers in Tengger Desert, the water content of different sand dunes in Minqin and Ningxia of Gansu Province was studied. The results show that the spatial variation of water content in the southern margin of the Tengger Desert is obvious and vertically stratified. The water content of the flowing sand dune in the horizontal direction is higher than that in the semi-fixed and fixed dunes. The water content of the sand layer in the southeastern margin of the desert is obviously higher than Southwest edge. Gansu Minqin Sandy layer of high water content appears in the upper section of the section; Ningxia Zhongwei capillary tube above the water content of the sand layer, indicating that the sand layer of water from the precipitation. The water in the sand layer of the study area is mainly in the form of film water, and high content of film water rarely occurs in the desert area at the southeastern margin of the desert with more precipitation. The positive water balance in the sandstones of this area belongs to the positive balance of the special water in the desert area determined by the hydraulic properties of the sandstones. This can well explain the reason why there are more lakes in the desert and the groundwater resources are more abundant. The paper also proposed two modes of water transport in the study area.