地面磁共振探水技术的研究现状与展望

Research status and expectation of surface nuclear magnetic resonance technique for groundwater detection

地面磁共振(Surface Nuclear Magnetic Resonance,SNMR)技术作为一种非侵害性可直接探测地下水的地球物理方法,其理论和技术在近年来得到了快速发展。为了给国内研究者提供一个SNMR探水理论和仪器软硬件技术的全面参考,本文综述了各国研制的代表性SNMR探水仪性能以及特点,讨论了SNMR探水理论和正反演问题;并以地面磁共振探水仪为例,详细介绍了SNMR探水仪的软硬件关键技术,包括大功率发射技术、弱信号检测技术、数字信号处理技术。同时,本文也总结了近几年SNMR探水技术的新进展,并指出了该方法的发展趋势和目前仍然存在的技术问题,包括最大探测深度、信噪比、死区时间、测量效率、反演稳定性等问题,为SNMR技术在未来的进一步发展提供思路。

The surface nuclear magnetic resonance （SNMR） technique is a nonintrusive geophysical method that can directly explore the sub-surface groundwater distribution and give a quantitative determination result. The theory and technologies of this method have been developed rapidly during the recent few years. In order to provide domestic relevant researchers a comprehensive reference of SNMR groundwater detection theory and instrument hardware and software technologies, this paper presents a review of the performance and characteristics of the representative SNMR instruments developed by various countries, then the groundwater detection theory and the forward and inversion problems are discussed. Taking the SNMR groundwater detection instruments （JLMRS-I, JLMRS-II） developed by Jilin University as examples, this paper introduces the key technologies in detail, including high power transmission technology, weak signal detection technology, digital signal processing technology and etc. Besides, this paper summarizesthe new progress of SNMR groundwater detectiontechnology and points out the development tendency of this technique and current existing technical problems, including maximum detection depth, signal to noise ratio, dead time, measurement efficiency and inversion stability, which provides an idea for the further development ofthe SNMR technique in the future.