Assessing Environmental Hazard Vulnerability from Integration of Lineament from Aeromagnetic and Monte Carlos-Simulated Permeability Model from Borehole Data in Benin City, Nigeria
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Abstract 0022-2763 The study tries to evaluate environmental stability and hazard vulnerability in Benin City by predicting the environmentally stable and weak zones. Characterizing the near-surface geo-hazard conditions using the routine traditional Engineering/geotechnical studies offers limited/localized coverage, hence the challenge from the devastating effects of geo-hazard areas persists in the study area. Besides being cost intensive routine geotechnical technique offers limited solution, hence ineffective. The present study employs analytical method that provides a predictive model of the stability/vulnerability potential hence providing opportunity for possible preventive measures with extensive coverage in the entire area. Both aeromagnetic and borehole data were used while StratraExplorer and Geosoft software were used to run the analysis, simulation and integration to predict the environmental hazard vulnerability. The lineament feature from aeromagnetic data and effective permeability coefficients obtained from numerical simulations of the borehole data were integrated to predict stable and weak zones that determines the environmental hazard like flooding Result of the aeromagnetic analysis yielded good quality total magnetic intensity map reduced to the equator. Lineament maps generated from the total magnetic intensity data showed north, northeast and northwest as the dominant orientations. Six shale/clay horizons were delineated in forty five boreholes located in the area. The average thicknesses of the shale/clay ratio in the various horizons were subjected to twenty eight thousand simulation using Monte Carlo Simulation to yield high quality effective permeability coefficients distribution model. The result of the integration of the lineament and the effective permeability models yielded a hazard distribution/vulnerability model. The model shows that the central area is most vulnerable while the adjacent areas are moderately vulnerable with pockets of isolated areas with the least vulnerability. This thus effectively classified the study area in terms of the hazard/flooding vulnerability.
Publication Info:
Author: Ugbor, C.C. and Adibeli, E.R.
Volume: 60
Issue: March
Published By: Journal of Mining and Geology Vol. 60(1) 2024. pp. 73 - 90 Nigerian Mining and Geosciences Society (NMGS), 2024-03-01