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Richards LA, Fox BG, Bowes MJ, Khamis K, Kumar A, Kumari R, Kumar S, Hazra M, Howard B, Thorn RMS, Read DS, Nel HA, Schneidewind U, Armstrong LK, Nicholls DJE, Magnone D, Ghosh A, Chakravorty B, Joshi H, Dutta TK, Hannah DM, Reynolds DM, Krause S, Gooddy DC, Polya DA. A systematic approach to understand hydrogeochemical dynamics in large river systems: Development and application to the River Ganges (Ganga) in India. Water Res 2022; 211:118054. [PMID: 35066262 DOI: 10.1016/j.watres.2022.118054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 12/16/2021] [Accepted: 01/09/2022] [Indexed: 06/14/2023]
Abstract
Large river systems, such as the River Ganges (Ganga), provide crucial water resources for the environment and society, yet often face significant challenges associated with cumulative impacts arising from upstream environmental and anthropogenic influences. Understanding the complex dynamics of such systems remains a major challenge, especially given accelerating environmental stressors including climate change and urbanization, and due to limitations in data and process understanding across scales. An integrated approach is required which robustly enables the hydrogeochemical dynamics and underpinning processes impacting water quality in large river systems to be explored. Here we develop a systematic approach for improving the understanding of hydrogeochemical dynamics and processes in large river systems, and apply this to a longitudinal survey (> 2500 km) of the River Ganges (Ganga) and key tributaries in the Indo-Gangetic basin. This framework enables us to succinctly interpret downstream water quality trends in response to the underpinning processes controlling major element hydrogeochemistry across the basin, based on conceptual water source signatures and dynamics. Informed by a 2019 post-monsoonal survey of 81 river bank-side sampling locations, the spatial distribution of a suite of selected physico-chemical and inorganic parameters, combined with segmented linear regression, reveals minor and major downstream hydrogeochemical transitions. We use this information to identify five major hydrogeochemical zones, characterized, in part, by the inputs of key tributaries, urban and agricultural areas, and estuarine inputs near the Bay of Bengal. Dominant trends are further explored by investigating geochemical relationships (e.g. Na:Cl, Ca:Na, Mg:Na, Sr:Ca and NO3:Cl), and how water source signatures and dynamics are modified by key processes, to assess the relative importance of controls such as dilution, evaporation, water-rock interactions (including carbonate and silicate weathering) and anthropogenic inputs. Mixing/dilution between sources and water-rock interactions explain most regional trends in major ion chemistry, although localized controls plausibly linked to anthropogenic activities are also evident in some locations. Temporal and spatial representativeness of river bank-side sampling are considered by supplementary sampling across the river at selected locations and via comparison to historical records. Limitations of such large-scale longitudinal sampling programs are discussed, as well as approaches to address some of these inherent challenges. This approach brings new, systematic insight into the basin-wide controls on the dominant geochemistry of the River Ganga, and provides a framework for characterising dominant hydrogeochemical zones, processes and controls, with utility to be transferable to other large river systems.
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Affiliation(s)
- Laura A Richards
- Department of Earth and Environmental Sciences and Williamson Research Centre for Molecular Environmental Science, The University of Manchester, Williamson Building, Oxford Road, Manchester, M13 9PL, United Kingdom.
| | - Bethany G Fox
- Department of Applied Sciences, University of the West of England, Bristol, BS16 1QY, United Kingdom
| | - Michael J Bowes
- UK Centre for Ecology & Hydrology, MacLean Building, Wallingford, Oxfordshire, OX10 8BB, United Kingdom
| | - Kieran Khamis
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
| | - Arun Kumar
- Mahavir Cancer Sansthan and Research Centre, Phulwarisharif, Patna, 801505, Bihar, India
| | - Rupa Kumari
- Mahavir Cancer Sansthan and Research Centre, Phulwarisharif, Patna, 801505, Bihar, India
| | - Sumant Kumar
- Groundwater Hydrology Division, National Institute of Hydrology Roorkee, Roorkee, 247667, Uttarakhand, India
| | - Moushumi Hazra
- Department of Hydrology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, India
| | - Ben Howard
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
| | - Robin M S Thorn
- Department of Applied Sciences, University of the West of England, Bristol, BS16 1QY, United Kingdom
| | - Daniel S Read
- UK Centre for Ecology & Hydrology, MacLean Building, Wallingford, Oxfordshire, OX10 8BB, United Kingdom
| | - Holly A Nel
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
| | - Uwe Schneidewind
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
| | - Linda K Armstrong
- UK Centre for Ecology & Hydrology, MacLean Building, Wallingford, Oxfordshire, OX10 8BB, United Kingdom
| | - David J E Nicholls
- UK Centre for Ecology & Hydrology, MacLean Building, Wallingford, Oxfordshire, OX10 8BB, United Kingdom
| | - Daniel Magnone
- School of Geography, University of Lincoln, Lincoln, LN6 7TS, United Kingdom
| | - Ashok Ghosh
- Mahavir Cancer Sansthan and Research Centre, Phulwarisharif, Patna, 801505, Bihar, India
| | | | - Himanshu Joshi
- Department of Hydrology, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand, India
| | - Tapan K Dutta
- Bose Institute, Centenary Campus, P-1/12 C.I.T Scheme VII-M, Kolkata 700054, India
| | - David M Hannah
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
| | - Darren M Reynolds
- Department of Applied Sciences, University of the West of England, Bristol, BS16 1QY, United Kingdom
| | - Stefan Krause
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
| | - Daren C Gooddy
- British Geological Survey, Maclean Building, Wallingford, Oxfordshire OX10 8BB, United Kingdom
| | - David A Polya
- Department of Earth and Environmental Sciences and Williamson Research Centre for Molecular Environmental Science, The University of Manchester, Williamson Building, Oxford Road, Manchester, M13 9PL, United Kingdom
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Chakraborti D, Singh SK, Rahman MM, Dutta RN, Mukherjee SC, Pati S, Kar PB. Groundwater Arsenic Contamination in the Ganga River Basin: A Future Health Danger. Int J Environ Res Public Health 2018; 15:ijerph15020180. [PMID: 29360747 PMCID: PMC5858255 DOI: 10.3390/ijerph15020180] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 01/17/2018] [Accepted: 01/19/2018] [Indexed: 11/17/2022]
Abstract
This study highlights the severity of arsenic contamination in the Ganga River basin (GRB), which encompasses significant geographic portions of India, Bangladesh, Nepal, and Tibet. The entire GRB experiences elevated levels of arsenic in the groundwater (up to 4730 µg/L), irrigation water (~1000 µg/L), and in food materials (up to 3947 µg/kg), all exceeding the World Health Organization’s standards for drinking water, the United Nations Food and Agricultural Organization’s standard for irrigation water (100 µg/L), and the Chinese Ministry of Health’s standard for food in South Asia (0.15 mg/kg), respectively. Several individuals demonstrated dermal, neurological, reproductive, cognitive, and cancerous effects; many children have been diagnosed with a range of arsenicosis symptoms, and numerous arsenic-induced deaths of youthful victims are reported in the GRB. Victims of arsenic exposure face critical social challenges in the form of social isolation and hatred by their respective communities. Reluctance to establish arsenic standards and unsustainable arsenic mitigation programs have aggravated the arsenic calamity in the GRB and put millions of lives in danger. This alarming situation resembles a ticking time bomb. We feel that after 29 years of arsenic research in the GRB, we have seen the tip of the iceberg with respect to the actual magnitude of the catastrophe; thus, a reduced arsenic standard for drinking water, testing all available drinking water sources, and sustainable and cost-effective arsenic mitigation programs that include the participation of the people are urgently needed.
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Affiliation(s)
| | | | - Mohammad Mahmudur Rahman
- Global Centre for Environmental Remediation (GCER), The University of Newcastle, Callaghan Campus, Callaghan, NSW 2308, Australia.
| | - Rathindra Nath Dutta
- Department of Dermatology, Institute of Post Graduate Medical Education and Research, SSKM Hospital, Kolkata 700020, India.
| | | | - Shyamapada Pati
- Department of Obstetrics and Gynecology, Calcutta National Medical College, Kolkata 700014, India.
| | - Probir Bijoy Kar
- Surgical Oncologist, Barasat Cancer Research and Welfare Centre, Kolkata 700124, India.
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