Composite Landfill Characterization: An Integrated Geophysical Study

Geophysical methods provide non-invasive means of probing buried waste disposal sites.<br>Using a small composite waste site in northern Switzerland as an example, we obtain accurate<br>images of the host sedimentary succession and structure from 3-D seismic reflection and ground<br>penetrating radar (GPR) surveys. Lateral boundaries of the disposal site are clearly visible in<br>detailed images of the magnetic gradient field and in various maps constructed from conductivity<br>data. Tomographic inversion techniques applied to seismic refraction data provide information on<br>waste pit thickness variations. While individual geophysical methods are quite powerful for<br>mapping aspects of the shallow subsurface, our study highlights the need to acquire diverse data<br>sets. Only with independent subsurface constraints is it possible to obtain reliable models of the<br>earth so essential for environmental and engineering studies.