时域反射技术测量海洋沉积物含水量的研究

Research of Time Domain Reflectometry in Measuring Water Content of Marine Sediments

时域反射技术(TDR)已被广泛应用于农业、地学等领域的水体分布特征研究。经实验发现,当沉积物孔隙水的盐度高于约0.5%时,利用传统的TDR探针无法测量沉积物的含水量。通过对TDR探针进行改进,发现加套管的TDR探针可以测量高盐分沉积物的含水量。观测了向干砂中加入盐度为0、0.5%、2%和3.5%溶液过程中介电常数的变化情况,初步建立了此种情况下沉积物的介电常数与含水量间的经验关系式。这一研究将为TDR在海洋沉积物含水量和水合物饱和度测量等方面的应用提供新的方法与思路。

Time Domain Reflectometry（TDR） has been widely used in water system investigation in agriculture,geosciences,etc.The experiments in this paper show that with a conventional TDR probe we can not measure water content of the sediment where pore water salinity is higher than about 0.5% in weight.Therefore,a coated TDR probe was developed and successfully used in measuring water content of the high-salinity sediments.The dielectric constants were observed when adding solutions with 0,0.5,2 and 3.5 percent of salinity to the dry sands respectively,and the results were used to reveal the empirical relations between water content and dielectric constants,which enabled us measuring water content of marine sediments with TDR.The study have significances for introducing TDR technology in measuring water content and hydrate saturation of marine sediments.