腾格里沙漠宁夏中卫沙层含水量研究

Study on Moisture Content in Sand Layers of Tengger Desert in Zhongwei ,Ningxia

为了揭示腾格里沙漠地区沙层含水量、水分存在形式、运移和水分平衡等问题,对该沙漠东南部不同沙丘进行了含水量研究。结果显示,腾格里沙漠沙层含水量空间变化大,沙丘中、上部含水量低,下部与洼地含水量高。毛管水层指示毛管水上升高度一般为60cm左右,毛管水层平均含水量为14.9%。由于研究区相对降水量偏多,沙层水分存在饱和重力水、毛管水、高含量薄膜水和低含量薄膜水等多种形式,在毛管水层之上的沙层水分一般均为薄膜水,5%左右的高含量薄膜水的存在是该区沙层水分含量的突出特点。沙层中薄膜水带的上、中、下部均有含水量较高的层段,表明该区大气降水经蒸发、蒸腾之后,仍有剩余的水分向下入渗,并成为地下水的补给来源。

In order to reveal the moisture content in sand layers,the forms of the moisture,the moisture migration and equilibrium in the Tengger desert,we study the moisture content of different sand dunes in the southeastern part of Tengger Desert. The results show that the spatial variation of moisture content of sand layers in Tengger Desert is very great,and the upper part of sand dunes have low moisture content,while the lower part of sand dunes and the low-lying land have high moisture content. Capillary water layer indicates the height of capillary water is about 60 cm and the average moisture content of capillary water is 14.9%. Because of more precipitation in the studied area,there are saturation gravity water,capillary water,high moisture content and low moisture content of film water and other forms of water in this sand layer. Film water is usually in the up layer of capillary water,and the presence of about 5% of the high content film water is outstanding features in the area. The upper,middle and lower layers of film water in the sand layer have higher moisture content,indicating that the precipitation in this area still has residual moisture infiltrating downward after evaporation and transpiration,and becomes a source of groundwater recharge.