Academic Research

Advisor: Wenyu Yang, PhD, Research Associate, TU Dresden, and Associate Professor, Institute for Ecological Research and Pollution Control of Plateau Lakes, Yunnan University, Kunming 650500, China.

Abstract

Non-point-source pollution is a major concern for surface water due to its implications for aquatic ecosystems and human health. In the face of climate change, it has become imperative to study how this type of pollution behaves under varying climate conditions. This study focuses on assessing the present and future NPS pollution scenarios in the Elbe River with different climate information. The physical model SWAT is used to simulate river discharges, sediment, nitrogen, and phosphorus loads in present (1991–2020), near-future (2021–2050), and far-future (2071-2100) scenarios. The near- and far-future scenarios are based on SSP2-4.5 and SSP5.8.5 climate projections, respectively. After calibration and validation, the built model presents good performance, having sensitivity to groundwater, soil evaporation, baseflow, and runoff. The results revealed a decrease in streamflow discharge in both near- and far-future scenarios, while sediment load increased in the near-future but then declined. Both nitrogen and phosphorus loads decrease gradually over the century, with concentrations rising in the near future due to reduced discharge and decreasing in the far future as groundwater becomes a major water source, filtering pollutants and providing less polluted water to the river. Despite limitations in pollutant calibration and agricultural data input, the study underscores the behaviour of NPS pollution under different climate projections that could help policymakers tackle climate change and anthropogenic impacts on Elbe's pollutants.

Advisor: Mohammad Mozaffar Hossain, PhD, Professor and Shyamal Karmakar, PhD, Associate Professor of Environmental Science, IFESCU, Bangladesh

Abstract

Developing and testing hydrological models in data-poor regions like Bangladesh is vital in supporting water management facilities. In this study, Quantum-GIS was used to integrate the Soil and Water Assessment Tool (SWAT) to simulate streamflow and sediment transport in Halda Basin using three different digital elevation models (DEMs): ASTER, ALOS, and SRTM. This study reveals that though ASTER DEM delineates more accurate watershed sub-basins, SRTM delineates a more accurate stream network than ALOS and ASTER. Surface runoff curve number, baseflow, available water capacity of the soil layer, saturated hydraulic conductivity, threshold depth of water in the shallow aquifer required for return flow, groundwater evaporation coefficient, and deep aquifer percolation fraction are the sensitive parameters for the developed hydrological model. The model simulation was done for the years 1982-2017 (with a 3-year warm-up period), where the years 1985-2005 were the observation periods, 2006-2009 were used for calibration, and 2010-2012 were used for validation. For the calibrated models, calibration (R2 = 0.87 - 0.88, NS = 0.81 - 0.87) and validation (R2 = 0.95 - 0.97, NS = 0.84 - 0.93) using streamflow of Panchapukuria station suggested good agreement in the seasonal cycle of streamflow (except pre-monsoon and peak flows). Among the DEMs, SRTM shows an overestimation in streamflow and total sediment transport than ALOS and ASTER. The streamflow of the river is decreasing after the dam construction and showing the lowest amount in the pre-monsoon season. Sediment transport from the Halda to Karnaphuli river is 63745.30 to 93388.15 tonnes per year, following an increasing trend. This study improves understanding of the key processes of a catchment in a data-poor, monsoon-driven river basin and could serve as a baseline for scenario modelling (e.g., climate change) for future water management and policy framework.

Advisor: Mohammad Mahfuzur Rahman, PhD, Professor, IFESCU, Bangladesh

Abstract

Reducing water use is now a conservation activity on the environment, as unsustainable utilisation of water assets poses challenges, which are also identified with the production of water-consuming products, for example, pulp & paper. In our country, many research works are done on the improvement of raw materials from different available woods or non-wood products, challenges to implement different management approaches, and existing pollution from the pulp and papermaking industry to human and environmental health. But this study attempts to make an account of freshwater utilisation amounts existing in the production process of the paper industry for different raw materials. The operational water footprint approach for freshwater (blue water footprint) in a specific range limit of raw material input to the final product is followed to complete this study. The total average water footprints of paper products produced from secondary fibre (recycled waste paper) and harvested wood species (bamboo and pulpwood) are calculated as 100.22 m3 and 737.25 m3 to produce a ton respectively. The reuse of treated wastewater can save 48 m3/ton and recycled waste paper as raw material can save literally 637 m3/ton of freshwater. The variation of the mean water footprint (418.73 ± 450.45 m3/ton) of paper products in Bangladesh is considerably higher, and the probability density is lower than that of other countries (worldwide 1016.99 ± 374.92 m3/ton). This study reveals the benefit of using treated wastewater within the operational process of the industry, which helps to save our scarce resources. The recommendation for using recycled waste paper as raw material in paper industries is also reasonable.

This study applies hydro-numeric modeling to analyze flood characteristics in an 8 km section of the Old Elbe River using HEC-RAS 1D and BASEMENT 2D. DEM, break lines defining dikes, riverbed, and floodplain, alongside surface roughness variations, were used to refine hydraulic simulations. Mesh discretization was performed to assess 2D floodplain dynamics, while QGIS was employed for pre-processing and visualization. The study evaluates steady-state and subcritical flow regimes, specific discharge, flood extents, velocity distributions, and hydraulic depth variations. Sensitivity analysis was conducted to determine the impact of DEM resolution, mesh size alterations, and land use classifications (LULC) on flood extent and hydraulic parameters. Results show that finer DEM resolutions improve terrain representation, while roughness coefficients significantly affect flood depth, particularly in forested areas. Comparison with historical flood maps highlights discrepancies due to lower discharge values, suggesting the need for calibration and improved modeling approaches. Findings support informed flood risk assessments and sustainable watershed management strategies in dike-protected river systems.

This study employs numerical groundwater modeling to assess hydrological dynamics and water management within the Amsterdam Water Supply Dunes (AWD) in the Netherlands. Using MODFLOW, the analysis incorporates hydrogeological formations, infiltration mechanisms, and abstraction canals to evaluate groundwater flow, recharge, and extraction efficiency in a Managed Aquifer Recharge (MAR) system. The study focuses on simulating steady-state and transient groundwater conditions, examining boundary conditions, hydraulic conductivity, and water balance components using datasets sourced from DINOloket and literature reviews. Scenario analysis assesses the impact of climate change-induced drought and increased water demand on infiltration rates, groundwater availability, and system resilience. Model evaluation and sensitivity analyses validate simulation accuracy, ensuring reliability for water resource management decision-making. Findings highlight the importance of optimizing groundwater abstraction, maintaining artificial recharge stability, and adapting to potential climate-induced stressors to sustain potable water supply for Amsterdam. 

This study evaluates the effects of climate change and urbanization on groundwater recharge within the urban environment of Arusha, focusing on land use and land cover (LULC) transformations over time. Using historical and projected data from 1995, 2020, and 2050, groundwater recharge patterns are assessed under changing urbanization dynamics, household water use, and climate variability. A conceptual water balance model is developed based on precipitation estimates, evapotranspiration rates, impervious surface runoff, soil storage dynamics, and groundwater abstraction rates. Spatial recharge estimates highlight significant reductions in infiltration due to expanded urbanization and increasing impervious surfaces, while climate-driven precipitation variability further exacerbates recharge declines. Groundwater abstraction trends indicate increasing household and municipal water demands, surpassing natural recharge rates in projected scenarios. A comparative analysis of groundwater budget shifts reveals an estimated water table drop of approximately 88 meters by 2050 due to intensified extraction and reduced infiltration. The findings underscore the unsustainable nature of current groundwater use in Arusha and emphasize the need for adaptive strategies, including improved stormwater management, enhanced return flow utilization, and climate resilience measures. This research provides insights into sustainable groundwater resource management and informs policy recommendations for mitigating future water scarcity challenges in urbanizing regions.

This study leverages remote sensing techniques to assess agricultural water management within the Miandoab Irrigation Scheme (MIS) in Iran, focusing on evapotranspiration, biomass production, water productivity, and irrigation performance for key crops such as Alfalfa, vegetables, and others. Utilizing Landsat imagery processed through PySEBAL alongside integrated field data, this analysis explores seasonal and annual water consumption patterns, crop productivity, and irrigation efficiency, while also identifying water deficit hotspots. Statistical assessments of crop water productivity reveal discrepancies in water use efficiency, highlighting disparities among winter and summer crops. Furthermore, groundwater recharge modeling, in conjunction with relative water deficit analysis, provides insights into the impact of irrigation on regional hydrological balances. The study underscores the significance of optimizing irrigation strategies, implementing sustainable crop management practices, and integrating remote sensing data to achieve a balance between agricultural productivity and ecological preservation in water-scarce regions. These findings contribute to informed policymaking and improved water resource management in the MIS.

This study employs AquaCrop modeling to evaluate and optimize irrigation strategies for paddy cultivation in the Halda watershed, a region characterized by significant water dependency due to its dry-season crop cycle. Using six distinct AquaCrop models, the research compares the effects of soil types (sand vs. loam) and irrigation methods (rainfed, fixed, and automated) on biomass yield, evapotranspiration rates, and overall water productivity. Results indicate that sandy soil supports higher biomass production and lower transpiration than loamy soil, with automated irrigation significantly improving yield stability across soil types. Fixed irrigation demonstrates lower efficiency, particularly in loam, where biomass production is nearly half that of sandy soil, leading to reduced water productivity and higher evapotranspiration. The findings highlight automated irrigation as a superior strategy for optimizing water use efficiency, promoting sustainable paddy cultivation, and maintaining ecological balance in the watershed. This study offers valuable insights into water resource management, aiding in the development of sustainable irrigation policies for agriculture in water-scarce regions.

This study explores the optimisation of Agricultural Managed Aquifer Recharge (AGRIMAR) systems in saline delta environments for effective irrigation management under varied climatic conditions. AGRIMAR systems integrate catchments, reservoirs, infiltration wells, and abstraction wells to manage water resources sustainably. Using meteorological data from the Netherlands and Portugal, key parameters such as catchment area, reservoir dimensions, and well capacities were optimised to minimise costs while reducing system failures. For the Netherlands, optimised system dimensions achieved a total cost of approximately €0.1 million with 0.41% failure days; a 20% failure allowance significantly reduced costs. In Portugal, higher evapotranspiration rates and lower precipitation necessitated larger reservoir volumes and catchment areas, increasing the total cost to €0.24 million. Comparative analysis revealed climate-driven differences in runoff and water management efficiency. The study underscores the importance of tailoring AGRIMAR designs to regional climatic conditions, enabling sustainable irrigation practices and addressing water scarcity in saline environments.

This study investigates groundwater chemistry and contaminant transport processes in the urban environment of Arusha, Tanzania, using PHREEQC simulations to analyze ion balance, electrical conductivity, mineral saturation, and pollutant degradation pathways. Water samples from a local dug well were analyzed for key physicochemical parameters, including pH, alkalinity, major cations and anions, and microbial contaminants, with PHREEQC calculations indicating an ion balance error of 0.08% and an electrical conductivity of 1633 µS/cm, closely matching the measured value of 1600 µS/cm, confirming calcite precipitation due to supersaturation. The environmental fate of sulfamethoxazole (SMX), a commonly detected antibiotic, was explored, with expected groundwater metabolites under aerobic conditions identified as 4-aminobenzolsulfonate and 3-amino-5-methyl-isoxazole. Additionally, a 1D transport model was developed to simulate septic wastewater infiltration over 50 years in the Sombetini neighborhood, highlighting key geochemical processes such as pyrite oxidation, nitrate reduction, and iron mobilization, where pyrite reactivity intensified beyond 25 meters, generating Fe²⁺ and SO₄²⁻ as nitrate concentrations declined. Findings demonstrate that nitrate contamination from onsite sanitation significantly impacts aquifer chemistry, reinforcing the need for improved wastewater management strategies to mitigate water quality degradation, while controlled wastewater infiltration approaches could aid in nitrate reduction via pyrite interactions, supporting sustainable groundwater resource management and policy development for groundwater protection in urbanizing regions.

Assisted in MSc thesis work of Md. Nazrul Islam, under the supervision of Dr. Shyamal Karmakar, Associate Professor, IFESCU.

Abstract

Assessment of heavy metal loads in the Karnaphuli upstream water was carried out in the present study for Iron (Fe), Cadmium (Cd), Chromium (Cr), Copper (Cu), Nickel (Ni), Lead (Pb), Zinc (Zn), and Arsenic (As). The main objective of the investigation was to assess the heavy metal concentrations and understand geogenic reactions. The highest concentrations of the heavy metals in the water samples were found to be 1.869 mg/l for Fe, 0.417 mg/l for Zn, 0.245 mg/l for Cr, 0.086 mg/l for Cu, 0.034 mg/l for Ni, and 0.010 mg/l for Arabunia, Kolabunia, Subolong Bazar, Borodham, Near Circle waterfall, and Borodham areas, respectively. The highest concentrations of heavy metals in sediment samples were found to be 6.187 μg/g for Fe, 1.932 μg/g for Zn, 1.713 μg/g for Ni, 1.296 μg/g for Cu, 1.095 μg/g for Cr, and 0.009 μg/g for Cd. The mean values of the heavy metal loads in water were found to be 1.023 mg/l for Fe, 0.167 mg/l for Zn, 0.020 mg/l for Ni, 0.019 mg/l for Cu, 0.019 mg/l for Cr, and 0.006 mg/l for Cd. The mean concentrations of the heavy metals in the sediment samples were found to be 5.397 μg/g for Fe, 1.351 μg/g for Zn, 1.002 μg/g for Ni, 0.809 μg/g for Cu, 0.632 μg/g for Cr, and 0.007 μg/g for Cd. According to the concentration order of metal ions in water, they were Fe > Zn > Ni > Cu > Cd > Cr, and in sediment, they were Fe > Zn > Ni > Cu > Cr > Cd. Significant variations were found among stations for all heavy metals except Cd in water and sediment. The mean values of Fe, Zn, Ni, Cu, Cd, and Cr were found to be lower than the prescribed standard values for the safe limit of heavy metals in surface water. Conversely, Cu, Ni, Zn, and Cr were found to be higher than the recommended value for riverbed sediment, as per ECR 1997 and WHO Standard 2004. The concentrations of As and Pb were not detected by the atomic adsorption spectrophotometer, which suggests these metal ions were below the detection limit in the study area.

This study examines the geo-electrical characteristics of groundwater formations in Breevenen, Netherlands, aiming to interpret subsurface lithological variability and aquifer potential. Borehole data were grouped and schematised into lithological logs for integration with geo-electrical Vertical Electrical Sounding (VES) measurements. West-East and South-West to North-East cross-sections reveal connections between fine sand, coarse sand, and clay layers, contributing to aquifer identification. Resistivity interpretations highlight saline marine clays within the Breda formation as critical features influencing aquitard properties. Calibration tables of formation and pore-water resistivities enabled detailed classification of rock types and water content, distinguishing freshwater from saline zones. The study underscores the importance of accurate geo-electrical analysis for groundwater resource management in complex lithologies.

This study explores variable-density groundwater flow modeling using SEAWAT to simulate saline-freshwater interactions in coastal and island aquifers under various hydrogeological scenarios. It evaluates the performance of different advection solvers, examines the effects of parameters such as dispersion, density variation, and freshwater inflow reduction, and determines sustainable groundwater extraction rates to prevent saline upconing. Analytical and numerical solutions are compared to assess model accuracy, and measures like artificial recharge and saltwater barriers are proposed to improve coastal aquifer management. Real-world cases, including Henry's and Elder's benchmarks, illustrate saltwater intrusion dynamics and mitigation strategies, highlighting SEAWAT's utility in groundwater quality analysis and sustainable resource planning.

Assisted in MSc thesis works of Nilotpal Sarkar, under the supervision of Dr. Shyamal Karmakar, Associate Professor, IFESCU.

Abstract

Swamp forests are considered a crucial component of the environment from the biodiversity and climate change mitigation points of view. This study was conducted in Ratargul Swamp Forest and Lakshmi Baor, situated in the North-Eastern Great Depression region of Bangladesh, to assess the soil organic carbon (OC) and soil organic matter (OM). Grab soil sampling was followed for the collection of soil samples. Samples were collected from three land classes based on elevation from the water level, viz., low, medium, and high inside the swamp forest, where few control samples were collected from the adjacent non-inundated area. Samples were collected from two layers – 0-15 cm and 15-30 cm from each sampling point after making a composite sample following the standard soil sampling procedure. The collected soil samples were analyzed for soil organic matter and organic carbon contents in the lab following the standard protocol of soil analysis. Lakshmi Baor has more organic carbon and organic matter concentration at 0-15 cm depth than 15-30 cm depth. On the contrary, the Ratargul Swamp forest soil sample showed higher organic carbon and organic matter concentrations at 15-30 cm depth than 0-15 cm depth. In the Lakshmi Baor area, total OC content was found higher in both layers of low land (19474.14 t C in 0-15 cm and 19748.20 t C in 15-30 cm). Whereas medium and high land showed significantly lower carbon concentrations. Total OC content was found higher in both low and medium land classes compared to high land in the case of Ratargul Swamp Forest. Land use class has no significant effect on the storage of soil OC and OM. In the case of Ratargul Swamp Forest, vegetation cover, barren land, and modified land have OC content of 4.59%, 5.04%, and 5.14%, respectively. Similarly, vegetation cover, barren land, and modified land have OC content of 4.86%, 4.54%, and 5.70%, respectively, in Lakshmi Baor. This result indicates higher OC storage compared to other terrestrial forest soils in Bangladesh. The findings of the study will help policymakers in formulating a new policy or strategy regarding carbon trading and swamp forest management in Bangladesh.

Assisted in BSc project work of Nilotpal Sarkar, under the supervision of Dr. Shyamal Karmakar, Associate Professor, IFESCU.

Abstract

Community-based forest management, popularly known as co-management, has been practiced in some important protected areas for the past 13 years. Financial aid has been provided by foreign donor agencies for capacity building in the forest departments as well as for creating alternative livelihoods for forest-dependent local people. However, the main objective of co-management is to arrest forest degradation and biodiversity loss. This study investigated whether such initiatives have improved the Teknaf Wildlife Sanctuary (TWS) in terms of people's livelihoods and tree diversity. Four out of the 10 beats of TWS were randomly selected for conducting a tree and regeneration survey. The phytosociological attributes of TWS were assessed and compared with the adjacent reserve forest (control site). Following a stratified random sampling procedure, a total of 39 square plots (20 m × 20 m) were established in both TWS (24 plots) and control (15 plots) sites. Results showed that TWS maintained greater tree diversity compared to the control site. Interviewing a total of 100 people (with only 60 involved in co-management), this study sought to determine the impact of co-management activities on people's livelihoods. Results showed that most of the respondents (about 60%) think the co-management committee is not functioning well, while 32% deemed it moderately good for people, and 10% believed it had a poor effect on people's livelihoods as well as forest conservation. Co-management is practiced successfully in many developing countries throughout the world for natural resource management. Further study may be conducted to find out the ways to make the co-management concept a successful forest management tool in Bangladesh.

As an assignment of the Human Dimensions in Environmental Management course, taken by Dr. Mohammed Al Amin, Professor, IFESCU.

This study presents a comprehensive Training Needs Assessment (TNA) for Forest Rangers, Foresters, and Forest Guards across five districts of Bangladesh—Chittagong, Feni, Noakhali, Patuakhali, and Cox’s Bazar—under the course “Human Dimensions in Environmental Management.” The primary objective was to identify critical competency gaps and develop a strategic training plan aligned with national climate-resilient afforestation and ecosystem management goals. Utilizing a mixed-methods approach, data were collected through Key Informant Interviews (KIIs), Focus Group Discussions (FGDs), and structured questionnaires administered to 57 forest personnel, subsequently analyzed using KJ and SWOT methods. The findings revealed considerable knowledge, skill, and attitude deficits, particularly in climate change adaptation (only 32% of foresters had prior related training), biodiversity conservation, modern silvicultural practices, and participatory forestry/co-management. Operational weaknesses included inadequate technical expertise, poor communication, and challenges from social/political interference and manpower crises, hindering effective management. The TNA culminated in a strategic five-day modular training framework tailored to each staff category, emphasizing core areas such as Climate Change and Carbon Sequestration, Social Forestry, Biodiversity Management, Monitoring and Evaluation, and Law Enforcement/Self-Defense, thereby highlighting the urgent need for targeted capacity-building to strengthen institutional competency and promote climate-resilient forest governance in Bangladesh.