Center for Environmental and Geographic Information Services

The Ganges-Padma River system, vital for millions of people in Bangladesh and India, is undergoing intricate morphological changes attributed to both anthropogenic and natural influences. The complexity of its evolution and the consequent impacts on riverbank erosion remain unclear, despite its importance for the means of living and sustenance of this region. This study aims to analyze the spatio-temporal planform changes and bank erosion dynamics of the Ganges-Padma reach in Bangladesh and understand the impacts of surficial lithology, river geometry, and hydrology on erosion. GIS-based spatio-temporal planform analysis has been conducted for this study utilizing Landsat satellite images from 1973 to 2020. The planform analysis with surficial lithology reveals a distinct connection between lithology and bank erosion. Riverbanks with non-cohesive materials face more erosion. Additionally, the study suggests the role of high river discharge during extreme flood events in exacerbating bank collapse. Maximum bank erosion was observed during the maximum flood event epochs (1987, 1988, and 1998). It is also found that the Ganges reach is becoming more sinuous with expanding channel width and sandbar area, while the Padma reach is shifting from sinuous to straight to braided over time. Statistical analysis further confirms that erosion is closely linked to river geometry. Increasing sandbar formation (R 2 =0.48) and river bathymetry (R 2 =0.50) increase river erosion. These findings provide a quantitative foundation for informed management; for instance, a 1 km 2 increase in sandbar area correlates with approximately 134.77 m of channel widening, while the high rate of expansion (92.32 m/y) in the Padma necessitates adaptive infrastructure planning. Understanding these river dynamics and analysis is imperative for the effective management and sustainable development of this expansive river system amidst growing anthropogenic pressures and environmental challenges.

Wetlands are vital to Bangladesh's biodiversity, environment, and economy, forming an integral part of the nation's ecosystem. Despite their ecological importance, these wetlands face significant challenges, including overfishing, pollution, and the adverse effects of climate change, such as rising sea levels. This study comprehensively analyzes the types, roles, and current threats facing Bangladesh's wetlands. It focuses on four main categories of wetlands: riverine wetlands, floodplain wetlands, coastal wetlands, and marshes/swamps/oxbow lakes/beels, covering between thirteen and eight million hectares, representing nearly half of Bangladesh's land area. Our key findings reveal that these wetlands support diverse plant and animal species, provide critical breeding grounds for aquatic life, and sustain livelihoods for millions. However, without effective conservation strategies, these ecosystems will likely degrade further, threatening biodiversity and economic stability. International agreements, such as the Ramsar Convention, alongside domestic legislation, show promise but sustained and integrated conservation efforts are essential to safeguard Bangladesh's wetland biodiversity for future generations.

The purpose of this study is to evaluate the adverse impact of groundwater flow path fluctuations and velocity in the water-stressed drought-prone northern region of Bangladesh. By the integrating geospatial technique and the Darcy flow model computes the volume balance and flows velocity of groundwater flow path fluctuations visualization and flow trends. The residual volume of groundwater flow are decreased gradually, and the flow velocity increased in the last twenty years due to the changes of saturated thickness and hydraulic head. The mean value of flow velocity ranged between 5900 and 7300 m/year and increased in every season from 2001 to 2020. The volume balance residual shows a slight increase from 2001 to 2010, followed by a decrease in 2010–2020. The groundwater flow path fluctuations of the study area are intensely falling and changing its drifts. This findings are indicated that the groundwater flow paths fluctuation is in the Northern Bangladesh are dramatically falling and changing its pattern. This depletion is found on such areas, where occur more groundwater withdrawal for different purposes. Over 31% of the region of the study site is now experiencing severe and extreme drought owing to variations in the groundwater levels. The extraction of groundwater for irrigation, which has a substantial adverse impact on ecological systems and agro-agricultural output of the study area. The current situation of the Northern Bangladesh will be deteriorated significantly if we do not reduce the groundwater discharge from deep aquifers for irrigation and reduce the use of surface water.

Bangladesh is well-known as a developing nation around the world. Migration is common in Bangladesh, particularly within the country. To raise their living conditions (income, housing, education, health, communication, etc.), many people move to new areas. Dacope Upazila is located in the southwestern region of Bangladesh, and this study seeks to examine the factors that contribute to the dynamics of internal migration by assessing the social and economic changes in the living standard of internal migrants following the migration. Both primary and secondary data were analysed statistically. The use of a questionnaire survey has allowed for the collection of primary data. Priority ranking matrix, Satisfaction Index, Economic Status Index (ESI), and Social Status Index (SSI) were computed to analyse the data. Statistical methods were also used to derive demographic information of the migrants. The study found that the majority of migrants were men who were either unemployed or living in poverty. The lack of economic opportunities, the inability to protect one's financial well-being from natural disasters, and the absence of adequate market infrastructure were the primary driving forces of migration. Migratory choices are heavily influenced by economic factors, and a lack of employment opportunities was ranked as the top factor. The Satisfaction Index highlighted the high levels of contentment experienced by internal migrants. Both the ESI and SSI showed greater improvement in the migrants' social and economic standing after migration. One could say that internal migration has a significant effect on the resulting population.

Groundwater is a crucial resource for water supply and irrigation in many parts of the world, especially in the Middle East. The Eocene aquifer, located in the northern part of the West Bank, Palestine, is threatened by unsustainable groundwater abstractions and on-ground pollution. Analysis and management of this aquifer are challenging because of limited data availability. This research contributes to the long-term sustainability of the aquifer by model-based design of future abstraction strategies considered within an uncertainty analysis framework. The methodology employed started with development of a single-layer steady-state MODFLOW groundwater model of the area, followed by uncertainty analysis of model parameters using Monte Carlo simulations. The same model was afterwards coupled with a Successive Linear Programming (SLP) optimization algorithm, implemented in the Groundwater Management tool (GWM) of the United States Geological Survey (USGS). The purpose of optimization was deriving five optimal abstraction strategies, each aiming to maximize groundwater abstraction, subject to different constraints regarding groundwater depletion. Given the uncertainty of model parameters, the sensitivity and reliability of these optimal strategies were then tested. Sensitivity was checked for two optimal strategies by performing re-optimization with different values of uncertain model parameters (one at a time). Reliability of the five strategies was tested by analyzing the extent of constraints’ violation for each strategy when varying the uncertain parameters using Monte Carlo simulations. Finally, the model was used for determining capture zones of wells for the five optimal abstraction strategies, land-use in these capture zones, and the associated estimates of on-ground nitrogen loading. The developed strategies were then deployed in a web-based decision support application (named Groundwater Decision Support System—GDSS), together with other relevant information. Users can analyze results of different optimal strategies in terms of groundwater level variations and total water balance results, and test consequences of uncertain parameters. Capture zones of wells for different abstraction strategies, together with land-use and on-ground nitrogen loading in these capture zones, are also presented. Results show that critical uncertain parameters are recharge, hydraulic conductivity, and conductance at key boundary condition locations. Optimal abstraction strategies results indicate that an increase in total abstractions could be between 5% and 20% from the current level (estimated at about 56 × 106 m3/year, which is about 74% of estimated annual recharge). The uncertain parameters, however, are impacting the sensitivity and the reliability of the optimal strategies to variable degrees. Recharge and hydraulic conductivity are the most critical uncertain parameters regarding sensitivity of the optimal strategies, while reliability is also impacted by the level of abstraction proposed in a given strategy (number, locations, and abstraction rates of new wells). The main novelty and contribution of this research is in combining modelling, uncertainty analysis, and optimization techniques in a comprehensive decision support system for the area of the Eocene aquifer, characterized with limited data availability.