RESUMO
Engineering geological characterizations, and geophysical mapping of subsurface structures to monitor some susceptible infrastructural facilities to hazardous slopes for effectiveness, safety to lives and properties, in addition to policy management for sustainable development. Novel integrated engineering geology, geoelectrical resistivity (ER), and borehole data analysis, to characterize subsurface for slope instability, determining critical zones prone to hazardous slopes in Peninsular Malaysian (PM), east coast areas was focused on. Engineering Laboratory soil investigations using disturbed and undisturbed samples collected to obtain firsthand information on the subsurface soils, and rocks physical properties, integrated with ER data to obtain subsurface geoelectric profiles. Regions delineated as loose and marked as water saturated residual soils prone to slopes corresponds to ER values < 100 Ω-m. ER values between 100 ≥ 500 Ω-m, were delineated as residual soils zones devoid of water contents. Subsurface geoelectric profiles related to hard materials were delineated as weathered and fractured bedrock zones corresponding to ER values between 500 ≥ 2000 Ω-m. Granitic bedrock units delineated as subsurface lithological zones with ER values > 4000 Ω-m. Slope Mass Ratings (SMR), was carried out to construct suitability, and slope assessment system (SAS) model ratings map for the four classes obtained.
RESUMO
Understanding of the climate-water nexus for sustainability, required good knowledge of the climate effects on groundwater aquifer units, particularly in rural communities. The studies were achieved using RES2-D modelling of the subsurface structures at the study site. Geophysical exploration with the application of 2-D Electrical Resistivity Imaging (ERI), combined with Induced Polarization (IP) method, were carried out to identify groundwater aquifers during extreme weather at Kampung Kuala Pajam, Beranang, Selangor, Peninsular Malaysia. The signatures obtained from geophysical explorations were used to better understand the phenomena that are responsible for groundwater depletion in the area. In recent times, there had been seasonal fluctuations in the water supply from boreholes serving the community. During the drought season, subsurface underlain this area experienced perennial acute shortages of groundwater supplies due to annual climatic variations that call for immediate solution by meeting the agricultural, domestic, and industrial water usage of the State of Selangor. A Pole-dipole techniques, using seven parallel lines of 400 m each at 5 m inter electrode spacing deployed to study the groundwater accumulation/aquifers within the area. Saturated groundwater occurrences zones were delineated as areas with average resistivity values of about 125 Ω-m, with corresponding chargeability of 30 ms. The methods used identified major faults along the northeast-southwest (NE-SW) directions, suitable for groundwater occurrences with approximate volume of about 2.86 Mega cubic metre (CBM), to proffer lasting solutions to the challenges being experienced by the community using a climate-water nexus sustainability.
