通过对莫高窟戈壁土壤中主要盐分的检测和理化特性分析,发现在极干旱地区,土壤盐分对土壤水分的垂直分布产生了重要影响.以芒硝为代表的结晶盐分,其含量分布和理化特性与土壤水分分布非常吻合.0～20 cm以无水盐分(Na2SO4)为主,水分含量较低,是盐分集聚层:在20～50 cm以结晶盐分(Na2SO4·10H2O)为主,水分含量较高,是盐分析出层；50cm以下以膜状水盐溶液为主,水分含量较低.与附近含盐量较低的流沙相比,盐分使戈壁土壤的水分含量增大了10倍以上,在热动力学作用下使浅层土壤水分的活动能力大大增强,对GSPC系统水分的垂直运转和潜水蒸发产生了重要影响.这为极干旱区利用潜水进行生态恢复提供了新的可能,对莫高窟的文物保护也具有重要意义.%Through measuring and analyzing salinities' physical and chemical characteristics of Gobi soil near the Mogao Grottoes, we discovered that soil salinity had a great impact on the vertical distribution of soil water content. The content distribution, physical and chemical characteristics of crystal salinities, which was represented by mirabilite, tallied closely with the distribution of soil moisture. The depth from 0 to 20 cm was mainly dominated by anhydrous salinities (Na2SO4), and water content was relatively low, it was salt concentration layer. The depth from 20 to SO cm was mainly dominated by crystal salinities (Na2SO4 10H2O), and water content was relatively high, it was salt precipitation layer. The depth of below SO cm was mainly dominated by filmy salt solution, and water content was relatively low. Compared with near dune which had low salinity, salinity caused water content of Gobi soil increased by 10 times more. Under thermokinetics action, water movement was greatly increased in shallow soil. It is important to the upright water transport and ground water evaporation of GSPAC system. This offers a new way to ecological recovery by using ground water and also important to protect Mogao grottoes cultural relics.
展开▼
