Thesis Chapters by Md Ariful Islam
Department of Geology, University of Dhaka, 2019
Substantial fresh groundwater supply for industrial and household use, especially in the coastal ... more Substantial fresh groundwater supply for industrial and household use, especially in the coastal areas, require information about the saline-fresh water interface depth distribution, thickness of the freshwater aquifers and local lithology. Mirsharai Economic Zone is a proposed industrial area in the SouthEastern coastal region of Bangladesh under Chattogram district. To find easy-accessible and sustainable fresh water supply for this project Geophysical resistivity survey (Vertical Electrical Sounding and Constant Separation Traversing methods) were applied in the study area. VESs were conducted as near as possible to existing borehole installed with lithological and aquifer data which were produced by Institute of Water Modelling (IWM). Interpretation of VES 1D data using IX1D software and CST data produced multi-layered model of the subsurface base on apparent resistivity, which were than compared to borehole data and corrected to get a clearer picture of the ground. Few layers consisting of very fine to fine sand were silty clay to clay identified, among which sandy layers constitute aquifers, both fresh and saline. In some cases, it is impossible to distinguish between clay layers and saline water bearing fine sand layers solely based on resistivity, because they both show low resistivity value. The topmost layer shows a varied composition, resistivity (2-21 ohm-m) thickness (0.5-4 m). The deeper layers show alternation of sandy and clayey composition with resistivity range of 1-17 ohm-m for the clayey layers (including saline very fine-fine sand layers) and 18-85 ohm-m for sandy layers. The shallow aquifers typically found to contain saline water. The southeastern and northwestern (near the Feni river) parts of the study area have relatively thick aquifers that most probably contain fresh water, whereas the middle part has no thick fresh water bearing aquifers within 300m depth. This study provides depth to the fresh water aquifer as well as probable suitable and unsuitable region for groundwater development. To get more precise information for this complex geological set up greater number of VES points and other geophysical methods need to be used. ii | P a g e ACKNOWLEDGEMENTS
Saint Martin’s island is one of the unique coral islands and popular tourist destinations in Bang... more Saint Martin’s island is one of the unique coral islands and popular tourist destinations in Bangladesh due to its location.
The island is located in the southernmost part of Bangladesh in the Bay of Bengal. It’s about 7.3 km long and 1.75 km in maximum width at the edge of Uttar Para. The Island is aligned in NNW-SSE.
This report deals with the Geological Structure, Geomorphology, Hydrogeology, Environmental issues and overall Geology of St Martin Island.
First-hand data were collected using different geo-physical, chemical methods & laboratory analysis to prepare this report.
The aquifers found in the sandy layers & coquina beds above the bedrock were rich in sodium and bi-carbonate concentrations and bacterial contamination was found which is caused by poor sanitation system. Environmental depletion in St. Martin’s island is the main concern which needs to be resolved.
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Thesis Chapters by Md Ariful Islam
The island is located in the southernmost part of Bangladesh in the Bay of Bengal. It’s about 7.3 km long and 1.75 km in maximum width at the edge of Uttar Para. The Island is aligned in NNW-SSE.
This report deals with the Geological Structure, Geomorphology, Hydrogeology, Environmental issues and overall Geology of St Martin Island.
First-hand data were collected using different geo-physical, chemical methods & laboratory analysis to prepare this report.
The aquifers found in the sandy layers & coquina beds above the bedrock were rich in sodium and bi-carbonate concentrations and bacterial contamination was found which is caused by poor sanitation system. Environmental depletion in St. Martin’s island is the main concern which needs to be resolved.
The island is located in the southernmost part of Bangladesh in the Bay of Bengal. It’s about 7.3 km long and 1.75 km in maximum width at the edge of Uttar Para. The Island is aligned in NNW-SSE.
This report deals with the Geological Structure, Geomorphology, Hydrogeology, Environmental issues and overall Geology of St Martin Island.
First-hand data were collected using different geo-physical, chemical methods & laboratory analysis to prepare this report.
The aquifers found in the sandy layers & coquina beds above the bedrock were rich in sodium and bi-carbonate concentrations and bacterial contamination was found which is caused by poor sanitation system. Environmental depletion in St. Martin’s island is the main concern which needs to be resolved.