275-9 Hydrogeochemical Characterization of Tertiary Aquifers in Cox’s Bazar, Bangladesh Using Machine Learning Techniques

Session: Advancing the Understanding and Management of Groundwater Pollution with Arsenic and Other Geogenic Contaminants Using Geospatial Tools, Machine Learning, and Data Science, Part II

Presenting Author:

Sumiya Sadeak

Authors:

Sadeak, Sumiya¹, Ahmed, Kazi Matin Uddin², Mia, Md. Bodruddoza³, Khan, Mahfuzur Rahman⁴

(1) Geology, University of Dhaka, Dhaka, Bangladesh, (2) Geology, University of Dhaka, Dhaka, Bangladesh, (3) Geology, University of Dhaka, Dhaka, Bangladesh, (4) Geology, University of Dhaka, Dhaka, Bangladesh,

Abstract:

This study evaluates the hydrogeochemical characteristics and health risks associated with manganese contamination in the tertiary aquifers of Cox’s Bazar, Bangladesh. A total of 288 groundwater samples were collected from 36 monitoring wells to assess key geochemical parameters, including manganese, sodium, and chloride. Hydrochemical analysis revealed distinct water quality patterns among the aquifers, with the Dupi Tila aquifer exhibiting fresh and potable water, while the Tipam Sandstone and Bokabil Sandstone aquifers showed significant degradation due to saline intrusion and elevated manganese levels. Hydrochemical facies analysis identified Na–Cl–SO₄ water types, indicating the influence of saltwater intrusion and water-rock interactions. To predict groundwater quality, machine learning algorithms such as Random Forest (RF), Gradient Boosting Regressor (GBR), XGBoost, and Artificial Neural Networks (ANN) were employed. Among these, XGBoost demonstrated the highest predictive accuracy for the Water Quality Index (WQI), outperforming other models. Health risk assessments using the hazard quotient (HQ) approach highlighted manganese contamination as a critical concern, particularly for children, with several wells exceeding safe thresholds. Furthermore, increased fresh water need for the millions of forcefully displaced Rohingya Refugees in the study area make the situation more vulnerable. These findings emphasize the need for proactive groundwater management strategies, including regular monitoring and mitigation measures, to protect water quality and public health. Addressing manganese contamination and saltwater intrusion is essential for ensuring the long-term sustainability of groundwater resources in this vulnerable coastal region.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

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