固定沙丘土壤水分时空动态变化研究

Spatiotemporal Change of Soil Water in Fixed Sand Dune

通过对浑善达克沙地固定沙丘土壤水分的连续观测，研究了沙丘土壤水分时空动态变化规律。结果表明：固定沙丘不同部位生长末期土壤含水量低于生长初期，季节动态变化明显，可分为3个时期，土壤水分积累期（3—5月）、土壤水分消耗期（6～9月）、土壤水分稳定期（10月至翌年3月）；在空间上，各样地土壤含水量均随深度的增加而有所增加，整个土壤剖面自上而下按水分变化规律可划分为3层：表面干沙层、水分活跃层、水分相对稳定层。在不同部位各层的厚度并不相同，固定沙丘不同部位的水分也不相同，总体来说坡脚〉坡腰〉坡顶。

Based on continuous observations on soil water in fixed sand dunes in Hunshandake Sandy Land, the rule of dynamic spatiotemporal change of soil water in sand dune has been studied. The results show that at different part in fixed sand dune, the soil water in the end of growing period is lower that one in early growing period. There are three periods can be divided： accumulation period of soil water （from March to May）, consumption period of soil water （from June to September）, stabilization period （from October to next March ）. In space, soil water content increases along with the increase of depth, according to the changing rule of soil water, the soil profile can be divided into three layers from top to bottom： surface dry sand layer, water active layer and relative stable layer. Because of different depth of profile at different part, the content of water is different at different part of fixed sand dunes, the order is the bottom of dune 〉 the middle of dune 〉 the top of dune.