Application of the Electrical Resistivity Tomography to the Detection of Groundwater Level in Loess Tableland
The Jingyang south tableland belongs to loess plateau.The groundwater level in this area increases year by year due to agricultural irrigation,which induces large-scale loess landslide disaster.In order to find out the fluctuation of groundwater in the tableland,this paper adopts the electrical resistivity tomography,based on the change rule of resistivity with depth obtained from the inversion data and the change rule of water content with depth obtained from the boreholes.The approxi-mate position of groundwater level line in the tableland is tentatively inferred.In order to predict the buried depth of the water line accurately,the resistivity measurement test of loess in the laboratory was carried out with DDC-6 electronic automatic com-pensation instrument.The quantitative relationship between resistivity of loess and different water content was established.It is determined that the resistivity at the groundwater level line of loess tablelands in the study area is 28.35 Ω·m(that is,the resistivity value at the liquid limit of loess),and the corresponding water content is 30%.By combining the laboratory test results with the inversion data of the electrical resistivity tomography and verifying and analyzing the groundwater level measured by the drilling data,the stratigraphic structure,thickness of different soil layers and the buried depth of the groundwater level of the loess tablelands in the study area are obtained.The reliability of the indoor loess resistivity test results was confirmed,and the effectiveness of the high-density electrical method in loess groundwater level detection was also verified.The results can provide technical guidance for the study of groundwater level fluctuation and landslide prediction and early warning in the Jingyang south tableland.
loess tablelandJingyang south tablelandgroundwater levelelectrical resistivity tomographyloess resistivity
万方数据
维普
