腾格里沙漠沙坡头地区旱季沙层含水量

目的]研究腾格里沙漠沙坡头地区旱季沙层含水量、水分来源、水分存在形式、水分平衡等问题,为沙漠地区水分合理利用、沙漠化防治、沙地改良以及沙地农业生产提供科学依据。方法]利用轻型人力钻打孔取样,进行水分测定。结果]腾格里沙漠沙坡头地区旱季沙层平均含水量为1%~3%,一般具有分为3层的特点;沙层含水量存在明显的空间差异,洼地平均含水量最大,平坦高地和半固定沙丘中部含水量较低,流动沙丘中上部含水量最低;旱季时期沙层水分以薄膜水形式存在;研究区旱季沙层水分仍为正平衡,主要是由沙层的高入渗率和受蒸发影响深度小决定的;研究区有植被发育之处,在根系的吸水作用下沙层剖面中下部的含水量比无植被的剖面含水量低。结论]研究区旱季沙层含水量低,空间差异较大,沙层水分仍保持正平衡状态。

Soil Moisture Content in Sand Layers of Shapotou Area in Tengger Desert During Dry Season

Objective] The moisture content was researched and the sources, forms and balance of soil moisture and other issues at dry season in Shapotou area of Tengger desert were discussed to provide scientific bases for reasonable water use, desertification control, sand amelioration and the increase of agricultural production. Methods] Hole sampling was used by light drill, and the sand moisture was determined after that. Results] The average moisture contents of sand layers were 1% to 3% at dry season in Shapotou area of Tengger desert, and generally could be divided into three differentiable layers. The spatial variation of moisture content of sand layers was very great. The low-lying land had the highest moisture content; while the flat plateau and the middle parts of semi-fixed dunes had relatively lower moisture content; and the upper or middle part of sand dunes had the lowest moisture content. The moisture at dry season in this area might exist in the form of film water. Benefited from rapid infiltration and insignificant influence of deep sand layers by evaporation, wherein a positive balance still existed. Affected by root absorption, the moisture contents of vegetational sand at middle and deep layers were lower than those of the area with no vegetation grew. Conclusion] In Shapotou area, the moisture contents of sand layers were low and the spatial variation was significant, and they were balanced positively at dry season.