3D monitoring of volumetric water content using electrical resistivity tomography in municipal solid waste landfill

For 3D monitoring of leachates in a closed landfill, 3D electrical resistivity tomography is done by a 21 × 21 square lattice in an area of 1600 m². 56 samples were provided from 6 boreholes to measure the physical properties. In this study, one specific electrode array was used in laboratory measurements and also in field operations to improve comparison between measurements in laboratory and field operation with each other. After correction of temperature and compression effects on the electrical resistivity data in laboratory, a strong correlation was developed between electrical resistivity and volumetric water content of five borehole samples. The validity of the obtained mathematical relation was confirmed by using it in volumetric water content estimation of the sixth borehole. 3D monitoring of volumetric water content was done via measured electrical resistivity values in the landfill. The results indicated that uniform changes have occurred in those layers with depth from 7 to 10 m in comparison with lower depth layers. This is due to biodegradation and compression of wastes in deeper points. The results of this study are indicative of high efficiency of electrical resistivity tomography in 3D monitoring of leachate distribution in landfill.