流动沙丘干沙层厚度对土壤水分蒸发的影响

Influence of dry sand bed thickness on soil moisture evaporation in mobile dune

利用Micro-lysimeter对流动沙丘不同干沙层厚度下的土壤水分蒸发作了测定与分析,结果表明:当干沙层厚度发育达到5 cm以上时,流动沙丘干沙层厚度成为土壤水分蒸发的决定因素。随着干沙层厚度的增加,土壤蒸发量逐渐降低;各观测日的蒸发抑制率随着干沙层厚度的增大而增大;5 cm的干沙层对蒸发的抑制作用最大可达70.6%,30 cm的干沙层则最大可达92.38%;干沙层厚度与土壤蒸发量之间存在显著的线性关系。各气象因子以及湿沙层不同深度土壤体积含水率对土壤蒸发量的影响作用很小,相关分析均没有达到显著水平。

The soil moisture evaporation under the different thickness dry sand bed in mobile dune is measured and analyzed with Micro- lysimeter. The result shows that： when the dry sand bed thickness is more than 5cm, the dry sand bed thickness becomes dominant factor of soil moisture evaporation in mobile dune. With the dry sand bed thickness increasing, the evaporation quantity decrease gradually; the suppression rate of evaporation increases with the dry sand bed thickness increasing; there exists a significant linear relation between the dry sand bed thickness and evaporation quantity. The influence of meteorological factors and different depth soil moisture on evaporation is very small; the difference is not significant between the meteorological factors and evaporation quantity, also the different depth soil moisture and evaporation quantity.