Seepage always eventuates through the foundation of all dams. The flow of water through the dam body generate seepage forces and endanger the dam stability due to piping. Controlling seepage after construction is quite difficult and an expensive job, hence proper practices should be adopted for seepage remediation in the designing stage. In order to investigate the more effective techniques among downstream (D/S) sand filter with upstream (U/S) clay blanket and cutoff wall, the Baz Ali small dam was analyzed using finite element approach SEEP/W 2D. The seepage behaviour through the dam was intuited by employing 1 m thick clay blankets on the upstream side with extending lengths of 50 m, 100 m, 150 m, 200 m, 250 m and 300 m. Furthermore, 5 m, 7.5 m and 10 m deep cut-off walls having 0.5 m and 1 m thickness were embedded for seepage mitigation. The seepage values obtained from SEEP/W 2D models were compared with each other. The SEEP/W 2D results and cost analysis show that clay blanket is more effective and an economical technique than a cut-off wall for tackling seepage issue. Hence, an upstream blanket of 100 m length is more efficient to diminish the seepage up to 58.65% in contrast to the base case without the remedial system.

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Evaluations of a mineral resource are necessary for mineral rights, owners and investors alike. However, for resource evaluation the detail documentation of subsurface geological spatial distribution such as lateral and vertical extent of bedrock and topsoil, hydrogeological investigation and boulder characterisation is mandatory. Boulder is hard and crystalline compact rock block, which substantial presence in a deposit highly influence the drilling equipment selection. A traditional exploration technique particularly for granite resource evaluation is drilling. But even finite number of drilling sample fails in the accurate delineation of boulders because drilling is limited to small point and rock mass is heterogenous and thus immense portion of the deposit via drilling method remain discern. 2D electrical resistivity imaging (2D ERT) technique of the study area over an area of 3.5 km 2 was accomplished by six resistivity lines using a Schlumberger protocol with inner and outer electrode spacing of 5 m and 10 m respectively. Inverted resistivity images successfully identify the existence of boulders in the area of investigation in the topsoil region; characterized by high resistivity values more than 2400 Ω.m. Whereas, only one core log (BH3) out of three reported presence of boulders. Thus, the research study presented in this paper enables us to conclude that the combined application of borehole and ERT allows us to derive that 2D ERT enhances the resource evaluation efficiency and reduces the cost considerably for underlying subsurface geological characterization.

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This study has been conducted to find out the aquifer characteristics of Bagerhat Sadar and adjacent areas in Bangladesh using geoelectrical resistivity method and borehole logs. The interpretation of resistivity soundings (14 nos.) shows that the sub-surface lithological sequence can be divided into four geoelectric units. The deepest geoelectric unit (with resistivity from 8 Ohm-m to 18 Ohm-m) represents the deep aquifer with usually fresh water. Resistivity values of 12 ?m or more for this unit may indicate formation water as acceptable for coastal people. In the study area, the shallow aquifer inferred is not suitable for groundwater development.