Comparison between SVD-Based and Automatic Geophysical Inversion for Schlumberger VES Data: A Case Study from Konkan Coast, Maharashtra
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1G. Gupta*, 2S. Ramachandran and 3K. Tahama
| Bulletin of Pure and Applied Sciences.
Geology (Geological Science), Vol.42F, No.1, January-June 2023: P.88-105 |
| Original Article
DOI: 10.48165/bpas.2023.42F.1.8 |
Description
Description
Comparison between SVD-Based and Automatic Geophysical Inversion for Schlumberger VES Data: A Case Study from Konkan Coast, Maharashtra
1G. Gupta*, 2S. Ramachandran and 3K. Tahama
| Author’s Affiliations:
1KSK Geomagnetic Research Laboratory, IIG, Prayagraj, Uttar Pradesh 221505, India 2Dept. of Marine Geology & Geophysics, Cochin Univ. of Science & Tech., Kochi, Kerala 682016, India 3Indian Institute of Geomagnetism, New Panvel, Navi Mumbai, Maharashtra 410218, India
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| *Corresponding Author: G. Gupta, KSK Geomagnetic Research Laboratory, IIG, Prayagraj, Uttar Pradesh 221505, India
E-mail: gupta_gautam1966@yahoo.co.in
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| (Received on 25.01.2023, Revised on 20.03.2023, Approved on 12.05.2023, Accepted on 19.05.2023, Published on 15.06.2023)
How to cite this article: Gupta G., Ramachandran S. and Tahama K. (2023). Comparison between SVD-Based and Automatic Geophysical Inversion for Schlumberger VES Data: A Case Study from Konkan Coast, Maharashtra. Bulletin of Pure and Applied Sciences- Geology, 42F(1), 88-105. |
Abstract
A comparison is made between the resistivity modeling results obtained from Singular value decomposition (SVD) based geophysical inversion method and a semi-automated inversion scheme to assess the robustness of the SVD method. A total of 30 vertical electrical soundings (VES) data were collected from the hard-rock area of Konkan coastal Maharashtra and modeled using the new method. The results are interpreted so as to identify the coastal aquifers contaminated with saline water in the study area. The SVD- based inversion results suggest a very high resistivity formation in the north-eastern part of the area, presumably due to the presence of laterites at the top, followed by hard and compact basalts beneath. In the south-eastern part of the study area, a very high resistivity zone is evident, due to the presence of laterites and basalts. A very high conductive zone is revealed in the south-western part near the coast signifying extensive influence of saline water ingress, which diminishes from south-west to north-eastern part of the region. It is also seen that the results obtained from the SVD-based algorithm is superior to the conventional inversion scheme.
Keywords: Singular value decomposition (SVD), resistivity, saline water ingress, Konkan, Maharashtra
