Electrical resistivity tomography and induced polarization study for groundwater exploration in the agricultural development areas of Brunei Darussalam

Abstract

Electrical Resistivity Tomography (ERT) and Induced Polarization (IP) study was carried out for groundwater exploration at eight agricultural development areas in Brunei Darussalam. The study was undertaken to meet the growing demands of water supply in the Brunei agricultural sector, particularly for paddy eld irrigation. A total of nineteen survey lines with survey lengths of up to 800 m and investigation depths of up to 150 m below ground level were conducted to delineate subsurface geological structures, formations and aquifer zones in the study area. Aquifer zones with resistivity values ranging from 1 to 100 ohm-m and chargeability values of less than 1 mV/V were detected in all surveyed locations. New groundwater well drilling was conducted at two of the surveyed sites based on interpretations of 2D resistivity and chargeability inversion models. Water well drilling encountered aquifer zones, which were primarily in sandy layers. Hydraulic tests revealed groundwater yields of 4.3 and 288 m³/day. Estimated transmissivity values of the aquifer units based on pumping tests are 0.53 and 109 m²/day, while their hydraulic conductivity values are 0.05 and 2.75 m/day. Estimated parameters of the aquifer units indicate weak to moderate groundwater yield for withdrawal and distribution for irrigation purposes at the investigated sites. The present study helped decision-makers take suitable measures for placing future irrigation wells and achieve signi cant groundwater exploration results in the study area.

Methods for the Geophysical Exploration and Sustainable Utilisation of Coalbed Methane Resources in Abandoned Mines of Shanxi, China

“…The mine DC method cannot accurately delineate anomalies, and its inversion methods require further research. Further research is also needed on well-ground and interhole resistivity imaging techniques, as well as 3D resistivity imaging and other emerging technologies [47,48].…”

Groundwater mapping of urban and coastal areas in Brunei

“…Moreover, the hydraulic gradients towards the South China Sea vary between 0.004 to 0.08. Thus, assuming an aquifer thickness of 10 to 20 m within the weathered zone, and hydraulic conductivities of 1•10 −5 to 1•10 −4 m•s −1 (Azffri, Ibrahim and Gödeke, 2022), one can estimate a submarine groundwater discharge (SGD) flux of 4.7•10 −7 to 4.0•10 −4 m 3 •s −1 per unit width. However, further studies in this regard are needed to confirm these estimates.…”

“…However, the increasing population and rapid urbanisation are putting increasing stress to the water resource in the country (Suhip et al, 2020). As a result, groundwater use has been subject to research and attracted much attention, particularly in rural and water-scarce areas (Azffri et al, 2022;Azffri, Ibrahim and Gödeke, 2022). Moreover, the study of water quality using geochemical indicators has been limited (Azhar et al, 2019;Gödeke et al, 2020;Azffri et al, 2023).…”

“…Moreover, the study of water quality using geochemical indicators has been limited (Azhar et al, 2019;Gödeke et al, 2020;Azffri et al, 2023). Recent studies have found that the groundwater level in Brunei is generally shallow, up to 20 m below ground level (Azffri, Ibrahim and Gödeke, 2022), and a predicted mean annual recharge rate is 800 mm•y -1 (Moeck et al, 2020).…”

Hydrogeological characterization of the Complex Terminal aquifer using geoelectrical investigation in the arid environment of Chetma-Biskra (South-East of Algeria)

“…Groundwater is considered the largest resource of fresh water at global scale and plays a vital role in securing the water supply and irrigation in arid environments when surface water resources are limited (Azffri et al, 2022). Due to the expansion of water use, overexploitation and pollution, groundwater availability decreased (Albrecht et al, 2017) and declined in quality.…”