毛乌素沙地典型流动沙丘水分深层渗漏量及动态特征

Water Seepage and Its Dynamic Characteristics in Deep Layer of Typical Mobile Dune in Mu Us Sandland

水分是干旱、半干旱区生态系统中最重要的限制因子,一直以来都是研究的热点问题。然而由于测定方法的缺失,流动沙丘深层水分渗漏量的动态变化特征缺少令人信服的直接证据。采用YWB-01型水分深层渗漏记录仪,研究了毛乌素沙地流动沙丘降雨入渗过程及150cm深度处的深层渗漏特征。结果表明:2011年5月14日到2014年7月14日,深层渗漏量≤1mm的天数为793天,占总观测到渗漏时长的81.5%,深层渗漏量占总渗漏量的21.3%;深层渗漏量≥10mm的天数为18天,占总观测到渗漏时长的1.85%,深层渗漏量占总渗漏量的33.3%。集中补给期主要在6—9月,渗漏量分别占各年总渗漏量的70%以上。深层渗漏量和降雨量之间均呈显著正相关关系。

Water is the most important limiting factor in arid and semi-arid ecosystems, and has always been a research hotspot. However, due to the lack of measurement methods, the scientific explanation of the dy- namic variation characteristics of water seepage in deep layer of mobile dunes still lacks convincing direct evidence. In this paper, the YWB-01 water seepage recorder was used to study the process of rainfall infil- tration and the characteristics of deep seepage at the depth of 150 cm in mobile sand dune in Mu Us sandy land. The results showed that, from May 14, 2010 to July 14, 2014, the number of days with ~1 mm deep seepage was 793, and was 81.5 % of the total observed seepage time, the deep seepage accounted for 21.3 % of the total seepage volume. The number of days with ≥10 mm deep seepage was 18 days, and was 1.85% of the total observed seepage time, the deep seepage accounting for 33.3 % of the total seepage volume. Concentrated supply period was mainly in June to September, the seepage accounted for more than 70 % of the total annual seepage volume. There was a significant positive correlation between seepage and rainfall.