http://reposit.library.du.ac.bd:8080/xmlui/xmlui/handle/123456789/1836 Tue, 07 Apr 2026 01:55:49 GMT 2026-04-07T01:55:49Z http://reposit.library.du.ac.bd:8080/xmlui/xmlui/handle/123456789/4636 Study on aquifer environment in the arsenic affected areas of Mhandpur and Madaripur districts of southern Bangladesh Zahid, Anwar This thesis is submitted for the degree of Doctor of Philosophy. Sat, 24 May 2025 00:00:00 GMT http://reposit.library.du.ac.bd:8080/xmlui/xmlui/handle/123456789/4636 2025-05-24T00:00:00Z http://reposit.library.du.ac.bd:8080/xmlui/xmlui/handle/123456789/4635 A contribution to the stratigraphy and paleontology of the Barail group in some parts of North-East India S. K. Modak This thesis is submitted for the degree of Doctor of Philosophy. Sat, 24 May 2025 00:00:00 GMT http://reposit.library.du.ac.bd:8080/xmlui/xmlui/handle/123456789/4635 2025-05-24T00:00:00Z http://reposit.library.du.ac.bd:8080/xmlui/xmlui/handle/123456789/2840 Groundwater Contaminant Transport Modeling and Aquifer Vulnerability Assessment of Gazipur District, Bangladesh Raza, Md. Jowaher Gazipur District is located in the Dhaka Division of central Bangladesh, covering an area of approximately 1,741 square kilometers, of which 17.53 km 2 is river and water bodies, and 273.42 km 2 is forest area, while the rest includes rural and urban settlements, agricultural lands, and industrial areas. As per the 2021 census the total population of the district is approximately 3.4 million, one of the most populous districts in the country. Gazipur is situated north of the capital city, Dhaka, and shares its borders with Mymensingh, Tangail, Kishoreganj, Narsingdi, and Narayanganj. It has a tropical monsoon climate characterized by high temperatures and heavy annual rainfall. The average annual temperature in Gazipur ranges from 25 to 30°C, with the highest temperatures occurring between April and June. The average annual rainfall in the district is around 2,200 millimeters, with the highest precipitation occurring during the monsoon season from June to September, while the dry season from December to February typically experiences little to no rainfall. Gazipur District is divided into five administrative Upazila or sub-districts, viz., Gazipur Sadar, Kaliganj, Kapasia, Sreepur, and Kaliakair. Due to a wide range of economic and industrial activities, and fast-growing job market, movement of people form the neighbouring rural areas resulted into a continuous rising trend of population, that doubled during the last two decades. It is a major industrial city, a hub for the country’s textile industry with almost 1500 industries. About one-third of the export-oriented ready-made garment factories of the country is located in the district, resulting in significant urbanization over recent years, with drastic changes to infrastructures. The district has been facing a significant increase in groundwater extraction over the years, due to population growth, urbanization, and industrialization. Almost all the drinking water supply in the area comes from groundwater sources. Rapid urbanization and industrialization caused sharp rise in abstraction of groundwater alongside the preexisting usage for irrigation. The highest groundwater consumption is in the urban (85%) and industrial settings (15%). Groundwater reserves are dwindling due to the continuous increase of uncontrolled abstraction alongside gradual decrease in recharge rate due to change in land use an land cover types. Higher abstractions and lower recharge result in an average annual drop of >2 meters in the groundwater levels of the underlying aquifers. This research aimed to determine the impact of rapid urbanization and increasing industrialization on groundwater in the Gazipur District; and relate contamination levels of groundwater with growing land cover and land use changes. To meet the increased demand for water, there has been a surge in abstraction, which raised challenges in managing water resources and caused sustainability challenges. Electrical conductivity (EC) and Total Dissolved Solids (TDS) were measured throughout the district between 2018 to 2021. Over the years, the average high EC value increased from 1071 μS/cm to 1781 μS/cm, higher values in urban and industrial areas of the District. A similar comparative increasing trend can be observed with historical measurements. Contaminants introduce additional ions into the water causing an increase in EC values, indicating contamination. This increase can be attributed to the heavy metal from industrial waste and domestic effluents into groundwater, observed within the main urban and industrial settings of the district. A detailed sampling plan was prepared with a target to cover the district's main urban settlements, industrial hubs, growing areas, forests, and agricultural areas. A Total of 143 groundwater samples were collected from the district and analyzed; thirteen parameters were considered for WQI calculation: pH, TDS, sodium, potassium, calcium, magnesium, iron, manganese, bicarbonate, chloride, sulfate, nitrate, and fluoride. The computed WQI shows that 48% of the water sample falls in excellent and 48% in good water categories. Spatially, WQI values exceed the limit in areas with high urbanization and industrialization setups. Significantly high values were found in the eastern part of Kaliakair, the central part of Gazipur Sadar, the northern part of Sreepur, the eastern part of Kapasia, and the northern part of Kaliganj within the growing urban and industrial areas of the district. Urbanization and industrialization lead to an increased demand for water, affecting quality and sustainability of groundwater. The DRASTIC method has been modified to assess groundwater vulnerability by incorporating population density, an outcome of urbanization and industrialization. The new assessment methodology of groundwater vulnerability is termed as DRASTIC-P. According to the new produced DRASTIC-P Map, urbanization and industrialization have been found to be hazardous activities impacting the district’s groundwater resources. According to the vulnerability map most part of the district is impacted, with minimum impacts in the southeastern part. Industrial processes often use large amounts of water, and the growing population in urban areas also requires more water for domestic use. This increased demand lead to the over-extraction of groundwater, causing depletion of aquifers and lowering of the water table. The solute transport model predicts spreading contaminants will spread to the neighboring regions in less than ten years. Flow is more rapid in the regions with high abstraction rates. This study indicated the limitations of modeling using hypothetical data and generalized information. Though MODFLOW will give a generalized flow pattern and contamination transport, yet lack of data can make the observations flawed. Fundamentally, this study indicates that the cone of depression may expand outside the district area; hence, further work should concentrate on a more precise measurement of in-situ hydrogeological parameters. A thesis submitted to the Department of Geology under the Faculty of Earth and Environmental Sciences, University of Dhaka, Bangladesh, as a requirement for the degree of Doctor of Philosophy in Geology. Sun, 10 Dec 2023 00:00:00 GMT http://reposit.library.du.ac.bd:8080/xmlui/xmlui/handle/123456789/2840 2023-12-10T00:00:00Z http://reposit.library.du.ac.bd:8080/xmlui/xmlui/handle/123456789/1837 A COMPREHENSIVE CONCEPTUAL STUDY FOR ECONOMIC DEVELOPMENT OF THE OIL FIELDS IN KAILASHTILA AND HARIPUR Islam, Mohammad Amirul Bangladesh occupies major part of the Ganges delta Basin and has been known as a natural gas rich province. However, occurrences of oil have been known in two small oil fields, Haripur and Kailashtila. While Haripur, discovered in 1986 was on production for six years, Kailashtila, discovered in 1988, was never put under commercial production. Energy experts recommend that development of the two discovered oil fields should be carried out. This process requires preparation of oil reservoir development plans, procurement of equipment and development of skilled manpower. Oil production data and record of six years of operation in Haripur oil field and oil flowing record during drill stem test operation in Kailashtila field have testified the production capabilities of the oil reservoirs in the fields. The present study suggests that the oil development works in these fields are terminated not because of depletion of reserves but because of not following the right procedures of the oil field development. In this study an effort has been made to prepare oil reservoir development plans on the two prospective oil fields. Comprehensive study on every aspects of oil reservoir such as seismic section, well logs, well test, core analysis, fluid analysis, fluid contacts leads to preparation of technically feasible and economically viable oil reservoir development plan. Oil reservoir development plan includes reservoir simulation models with defined oil recovery mechanism, optimum number of oil production wells, optimum number of water injection wells and mutual positions of wells in reservoir. Finite difference reservoir simulation model (conventional reservoir simulation model) and streamline reservoir simulation model are developed from seismic section, well logs, core analysis, fluid analysis, well test, drill stem test, fluid contact and production history. Oil recovery mechanism is optimized from analysis of reservoir pressure, rock properties, fluids properties and core flood test. Streamline simulation study is performed to optimize number of oil production wells, number of water injection wells and mutual positions of wells in the reservoir. Oil production rate, well head pressure, water injection rate, water injection pressure and production period are also defined in oil reservoir development plan. Finite difference reservoir simulation study is performed to optimize oil production rate, well head pressure, water injection rate, water injection pressure and production period. Finite difference reservoir simulation model and streamline reservoir simulation model have been constructed on oil reservoir in Haripur field. Then the oil reservoir models are validated by history matching with six years oil production data available. The reservoir has been screened to design enhanced oil recovery technique. Low salinity water (salinity 1000 ppm of NaCl) injection method has been recommended for oil reservoir to recover remaining oil. On the basis of oil recovery technique reservoir development variables have been optimized to generate reservoir development scenario. The oil reservoir has been proposed to develop with six water injection wells and two oil production wells. Streamline simulation has been run on the reservoir development scenario and observed the performance of the reservoir such as hydraulic conductivity, oil flow rate, oil flow direction, water flow rate, time of flight, water break through, water channeling and sweeping efficiency. The Haripur oil reservoir has shown good performance under the development scenario. The reservoir model with the optimum development scenario has been considered as reservoir development plan. The optimum reservoir development plan has been simulated by finite difference reservoir simulator for duration of twenty years for economic analysis of the development plan. Haripur oil field initially had 33 million barrels of oil and produced 0.53 million barrels of oil. Experts have predicted that there is remaining oil in the reservoir which is approximately 32.47 million barrels of oil. Six injection wells are used for water injection. Water injection pressure is 1000 psi. Well water injection rate is 300 stb/day and field water injection rate is 1800 stb/day. Two oil production wells are used for oil production. Well oil production rate is 400 stb/day and field oil production rate is 800 stb/day. Well head pressure of oil production well is 500 psi. Total oil recovery is about 5.844 million barrels within twenty years from Haripur field. Break even oil production is 2.044 million barrels of oil. Conventional and streamline reservoir simulation models of oil reservoir in Kailashtila field have been constructed by using seismic survey, well logs, core analysis, fluid analysis, fluid contact data and drill stem test data. Reservoir simulation models have been validated by oil production data from drill stem test operation. As the oil reservoir has significant pressure to lift oil to the surface as detected from drill stem test, natural depletion mechanism has been proposed to recover oil from reservoir. A single oil production well has been placed at the center of the oil reservoir in Kailashtila field for oil reservoir development. Streamline simulation has been run on the reservoir development scenario and observed the performance of the reservoir such as hydraulic conductivity and oil flow rate. The Kailashtila oil reservoir has shown good performance under the development scenario. The Kailashtila oil reservoir model with the optimum development scenario has been considered as optimum reservoir development plan. Twenty years oil production has been forecasted from the oil reservoir development plan by simulating the finite difference reservoir simulation model of Kailashtila oil reservoir. Experts have predicted that Kailashtila oil field initially has 94.33 million barrels of oil. A single oil production well is used for oil production. Well oil production rate is 817 stb/day. Well head pressure of oil production well is 500 psi. Total oil recovery is 5.973 million barrels from Kailashtila field. Break even oil production is 0.584 million barrels. The oil reservoir in Kailashtila field is able to produce 0.129 million barrels of additional oil than Haripur oil reservoir because Kailashtila oil reservoir contains lighter oil (42 oAPI) and Haripur oil reservoir contains heavier oil (28.5 oAPI). In this study maximum effort has been done concentrated in seismic and well logs interpretation as well as laboratory test to minimize data uncertainty for preparing reliable oil reservoir development plans on Haripur and Kailashtila fields. This thesis submitted for the degree of Doctor Of Philosophy in the Department of Geology, University Of Dhaka. Tue, 15 Feb 2022 00:00:00 GMT http://reposit.library.du.ac.bd:8080/xmlui/xmlui/handle/123456789/1837 2022-02-15T00:00:00Z