摘要:
根据罗布泊遥感影像图,在干盐湖区域选择“黑纹”和“白纹”观测区为典型研究对象,对其表层盐壳含水率、地下水位埋深、气象参量的动态变化进行了1年多的系统观测,结果发现两个观测区的表层盐壳的季节含水率存在一定的差异,其吸附水含水率均大于结晶水含水率,两观测区的吸附水含水率差异在1%左右,但黑纹观测区盐壳结晶水含水率是白纹观测区的3倍以上;黑纹观测区的地下水水位埋深相对稳定,表层盐壳的吸附水变化与地下水水位变化无明显的直接关系。另在高湿度、不同温度的野外环境和室内模拟环境下开展的盐壳吸水能力实验都发现,黑纹观测区盐壳的吸水能力明显强于白纹观测区,甚至达到10倍以上的差异,分析表明这和表层盐壳盐类矿物成分(如硫酸镁)的差异性密切相关。
关键词:
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罗布泊
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干盐湖
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盐壳
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含水率
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吸水特征
Abstract:
Two observing sites within the Lop Nur dry salt lake were selected as field experiment areas to monitor the moisture content change on the surface of salt-crust, groundwater level and meteorological data, and a systematic observation lasted for more than one year. One observing site has typical bright stripes exhibiting white color and is named WOS, and the other has typical gray stripes assuming black color and is called BOS. Based on the experiment, it could be concluded that the seasonal moisture values of salt-crust in the two observing sites are different: the adsorbed water content on the surface of salt-crust is higher than the crystal water content, with the difference of adsorbed water content in the two observing sites being about 1%; the content of crystal water in BOS is over 3 times that in WOS. The field observation data indicate that the groundwater level is relatively stable, and it makes little contribution to the adsorbed water content of the surface in salt-crust in BOS. The absorption capability of salt-crust in BOS is remarkably stronger than that in WOS both under the conditions of high humidity and different temperatures in field test or laboratory simulation test, and the difference of water absorption capability is even more than 10 times, probably caused by the difference of the mineral compositions, such as the content of magnesium sulfate in the two observing sites during the salt-curst formation and development.
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