地面核磁共振技术勘查西北干旱浅层地下水效果浅析

地面核磁共振技术勘查地下水是一种新的应用领域,该技术是目前国际上唯一的能直接进行地下水勘查的技术.我所自一九九九年引进法国Numis仪器以来,先后在陕西黄土区、宁南黄土区等地开展寻找不同类型浅层地下水的试验工作,取得了一定的野外成果.本文是在分析总结这些成果的基础上,针对存在的问题如强干扰背景下勘查结果的可靠性,同一测点"8”字型与"正方形”发射线框二者勘查结果比较等方面进行探讨分析.

Analysis on applied effectiveness of near-surface aquifers exploration with NMR technique in North Western arid area

The surface NMR technique prospecting groundwater is a new applied field,which is an only technique for a direct detection of groundwater in the world at present. NMR instrument allows invasive measurements of a NMR signal from subsurface water-saturated layers. Direct measurement of the signal from water molecules guarantees a high reliability of water detection. Interpretation of experimental date reveals location of aquifers, their depth and water content. Mean size of water-saturated rock pores can also be estimated. Sine the NMR instrument was introduced into our institute in 1999, It had been used to test the different near-surface aquifers explorations in the loess land of Shanxi Pr. and the south of Ningxia Pr., and a certain field results were obtained. Based on analysis of these results, this article discusses on the existing problem of the prospecting reliability in strong noises background, and the prospecting results comparison using a transmitting antenna of square loop and figure 8 shaped loop at the same testing site.