摘要
１９９３～１９９４年在腾格里沙漠西南缘邓马营湖北部一固定沙丘上设置观测点，采用中子仪、负压计逐日定时分层测定沙丘０～１７５ｃｍ深度含水量和水分势能．对实测资料加以分析表明：（１）沙丘水分深度分布剖面可划分为４层；表面干沙层、水分强烈变化层、低含水量缓变层、高含水量变化层；（２）依据水分势能变化特征，势能剖面可分为变化活跃区、频变区、突变区和缓变区．同时，结合沙丘水分时间变化特征，得出结论：水分势能与水分动态存在较好的对应性．从而表明由势能观点研究沙丘水分动态的可行性和正确性，为沙丘水分运移机理及运移方程的研究提供了一定的科学依据．
During the period of 1993 to 1994, the field experiments were carried out daily on time within the 0～175 cm depth of the fixed dunes which were located in the north of Dengmaying basin on the southwestern edge of Tengger desert to measure moisture contents and moisture potentials with sand layers by Neutron moisture meter and Tensiometer. Four layers were established in the depth distribution profiles of sand dune moisture according to the measured data analysis. The sand dune moisture variations were inferred as follows:(1)dry sand layer which lay on the dune surface;(2)within the depth 40 cm below dry sand layer, the moisture contents changed greatly, from about 1.10%～ 7.50% ;(3)within the depth 40 to 100 cm below, the moisture changed slowly, where moisture contents were 3.80%～ 6.70% ;(4)the sand layer of 100 to 175 cm in depth, the moisture varied from 5.00% to 8.00% . In addition, based on the characteristics of potential changes, the potential profiles could be divided into four zones where the potential changed actively, frequently, suddenly and slowly. Considering the moisture variations with time, we can get the conclusion:there is a good correspondence between moisture behavior and moisture potential changes. The results obtained show that it is feasible and correct to study moisture behaviors in terms of potentials, and this will provide a scientific basis for the research of the mechanism and equations of moisture transport in sand dunes.
出处
《兰州大学学报（自然科学版）》
CAS
CSCD
北大核心
1999年第1期218-224,共7页
Journal of Lanzhou University(Natural Sciences)
基金
国家自然科学基金
关键词
固定沙丘
水分动态
水分势能
沙漠区
fixed dune
moisture behavior
moisture potential
correspondence
