罗布泊干盐湖电磁感应电导率与“耳纹”成因关系探讨

The correlation between the electromagnetic induction measurements and pixel values associated with the "Great Ear" rings in Lop Nur

应用EM38大地电导仪对罗布泊干盐湖盐壳进行了不同空间分辨率的系统采点,初步探讨了“耳纹”形成的原因.结果表明:干盐湖盐壳电磁感应电导率在不同空间尺度上都表现出一定的韵律性变化,与遥感影像“耳纹”灰度变化有较好的相关性,全程50km范围内相关系数为-0.6154,40km范围内相关系数为-0.6891,呈显著负相关.据此推断“耳纹”的形成是由湖泊在逐渐萎缩、干涸过程中所引起的盐壳含盐量、含水量等理化性质的分异在遥感影像上的反映.

This study explores the cause for the occurrence of the rings of the ＂Great Ear＂ based on the electromagnetic induction measurements using EM38 on the dry lake salt crusts of LOp Nur at different spatial scales. Preliminary results indicate that there is a clear variation pattern in the electromagnetic induction measurements and it corresponds well, at different spatial resolutions, with the pixel values of the ＂Great Ear＂ rings revealed by the Landsat imagery. They seem negatively correlated. The correlation coefficient for the 50 km transect is - 0.6154 and the 40 km transect is - 0.6891. It is suggested that the occurrence of the ＂Great Ear＂ rings on Landsat imagery is an indication of spatial zonal changes in salt and water contents, particle size, and other factors on the surface of the dry salt lake beds of Lop Nur.