地面核磁共振测深方法在武汉市岩溶地面塌陷探测中的应用研究  

Study on the application of surface nuclear magnetic resonance in the detection of karst collapse in Wuhan

作　　者：刘道涵[1,2] 张欣 何军 邬健强[1,2] 刘磊 LIU Daohan;ZHANG Xin;HE Jun;WU Jianqiang;LIU Lei(Wuhan Center,China Geological Survey,Wuhan,Hubei 430205,China;Central South China Center for Geoscience Innovation,Wuhan,Hubei 430074,China;Hubei Land Resources Vocational College,Wuhan,Hubei 430090,China)

机构地区：[1]中国地质调查局武汉地质调查中心,湖北武汉430205 [2]中南地质科技创新中心,湖北武汉430074 [3]湖北国土资源职业学院,湖北武汉430090

出　　处：《中国岩溶》2022年第1期13-20,共8页Carsologica Sinica

基　　金：国家自然科学基金(42107485);国家重点研发计划(2020YFC1512460,2018YFC800804);中国地质调查局项目(DD20190282,DD20221734)。

摘　　要：岩溶地面塌陷是隐伏岩溶区常见的地质灾害类型之一,是制约武汉市城市规划和建设的重大地质环境问题。地下水对岩溶地面塌陷的形成和发展发挥着至关重要的作用,地面核磁共振测深方法是目前唯一直接探测地下水的地球物理方法,对地下水探测具有独特优势。本文介绍了地面核磁共振测深方法在探测岩溶塌陷区地下含水层方面的潜力,并在武汉市岩溶塌陷区内外开展了探测实验,结果表明:地面核磁共振测深反演的含水量参数可辅助划定含水层顶底板埋深,确定含水层厚度,并量化含水层富水性特征;弛豫时间参数指示了含水层孔隙度大小,可为岩溶发育程度、岩溶裂隙充填情况等提供参考。结合钻孔资料,验证了地面核磁共振测深方法在岩溶塌陷区地下含水层探测中的可行性。As one of the common geological disasters in the covered karst area,karst collapse is a major geologi⁃cal environmental problem that restricts the urban planning and construction of Wuhan.It is recorded that the karst collapse in Wuhan first occurred in Dinggong street,Wuchang district in 1931.Till 2019,33 karst collapses(36 times)have occurred in Wuhan,which directly threatens the safety of people’s lives and property.Previous stud⁃ies show that groundwater is one of the most active elements,playing an important role in the formation and devel⁃opment of ground karst collapse.Therefore,exploring the occurrence state of groundwater,structural characteris⁃tics of aquifers,and hydrogeological conditions is of great significance for the study of karst collapse mechanism.Compared with the direct hydrogeological characterization such as drilling,hydrogeophysical methods supply cost-effective and dense spatial information about groundwater systems.Electrical,electromagnetic(EM)and sur⁃face-wave techniques have been widely used to noninvasively detect aquifer properties and to improve hydrogeolog⁃ical models.However,the validity of such methods is somewhat limited and their interpretation is non-unique as they are only indirectly sensitive to the hydrogeological parameters such as water content,hydraulic conductivity,transmissivity and porosity.At present,Surface Nuclear Magnetic Resonance(SNMR)is the only geophysical method to directly detect groundwater,which has unique advantages of high sensitivity,high efficiency and nondestruction in groundwater detection.Similar to medical MRI,NMR is applied as surface NMR(SNMR),bore⁃hole NMR(BNMR),and laboratory NMR(lab-NMR)in geophysics.During the last decade,SNMR has experi⁃enced great advancement in instrumentation improvement,signal processing,forward modeling and inversion tech⁃niques.In this paper,we presented the potential of SNMR in detecting the underground aquifer in the karst collapse area,and carried out exploration experiments inside and outside t

关 键 词：地面核磁共振测深 岩溶塌陷 武汉市 地下水 

分 类 号：P631[天文地球—地质矿产勘探] P642.26[天文地球—地质学]