Publication Date:
2020-12-07
Description:
Traditional electrode arrays such Wenner-Schlumberger or dipole-dipole are still widely used thanks to their
well-known properties but the array configurations are generally not optimized for multi-channel resistivity
measures.
Synthetic datasets relating to four different arrays, dipole-dipole (DD), pole-dipole (PD),Wenner-Schlumberger
(WS) and a modified version of multiple gradient (MG), have been made for a systematic comparison between
2D resistivity models and their inverted images. Different sets of array configurations generated from simple
combinations of geometric parameters (potential dipole lengths and dipole separation factors) were tested
with synthetic and field data sets, even considering the influence of errors and the acquisition velocity. The purpose
is to establish array configurations capable to provide reliable results but, at the same time, not involving
excessive survey costs, even linked to the acquiring time and therefore to the number of current dipoles used.
For DD, PD andWS arrays a progression of different datasets were considered increasing the number of current
dipoles trying to get about the same amount of measures. A multi-coverage MG array configuration is proposed
by increasing the lateral coverage and so the number of current dipoles. Noise simulating errors both on the electrode
positions and on the electric potential was added.
The array configurations have been tested on field data acquired in the landfill site of Bellolampo (Palermo, Italy),
to detect and locate the leachate plumes and to identify the HDPE bottom of the landfill.
The inversion results were compared using a quantitative analysis of data misfit, relative model resolution and
model misfit. The results show that the trends of the first two parameters are linked on the array configuration
and that a cumulative analysis of these parameters can help to choose the best array configuration in order to obtain
a good resolution and reliability of a survey, according to generally short acquisition times.
Description:
Published
Description:
34-48
Description:
7A. Geofisica per il monitoraggio ambientale e geologia medica
Description:
JCR Journal
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article