探地雷达技术对表层岩溶带典型剖面组构刻画与界面识别

Structure description and interface recognition on epikarst typical profiles using GPR technology

表层岩溶带是岩溶研究的重要对象,以往研究以剖面调查半定量为主,文章利用探地雷达属性技术对其发育情况进行定量研究。选取3个表层岩溶带的典型剖面(浅裂隙土、深裂隙土、厚土层覆盖),并采集探地雷达数据,通过提取相干体属性和均方根振幅属性来挖掘雷达数据中的潜在信息,用于区分介质组构和识别发育深度界面。结果表明,均方根振幅属性较好地区分出了浅裂隙土型和深裂隙土型的岩土介质,厚土层覆盖型的犁耕层与非犁耕层土壤介质;相干体属性能较好地识别出表层岩溶带和下部完整基岩,定量化其发育厚度。

Epikarst is an important object in karst study. Previous research was mostly based on soil profile survey with semi-quantitative methods. We utilized ground penetrating radar( GPR) technology to conduct a quantitative study on this issue. Three typical epikarst profiles s of are chosen,w hich are characterized by shallow fissure soil, deep fissure soil and thick soil coverage. From the data collected through GPR technology,root mean square (R MS) amplitude and coherence attributes were extracted to mine the potential information of the GPR data for differentiation of medium structure and surface recognition. The results show that the RMS amplitude attribute per mits to differentiate rock and soil of shallow and deep fissure soil types,cultivated and uncultivated layers in soil medium of thick soil cover type;w hile the coherence attribute can be used to recognize the epikarst and lower in tact bedrock and quantify the thickness of the epikarst.