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Karainagar Island, Jaffna, Sri Lanka
(Spatial ground elevation) |
Water security is a critical issue, particularly in island landscapes where access to freshwater resources is limited and vulnerable to various factors such as climate change, population growth, and overexploitation. Karainagar Island in Jaffna, known for its unique geographical setting and water challenges, serves as an excellent case study to understand the spatiotemporal dynamics of groundwater resources and their implications for water security.
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| Seasonal drought |
This study aims to comprehensively investigate the spatiotemporal variation of groundwater, particularly freshwater, at Karainagar Island, Jaffna.
Quantitative Assessment:
Quantify the distribution and dynamics of groundwater (Freshwater) across the island in different seasons and years.
36 dug wells for drinking, domestic, and agricultural purposes located across the island were chosen for measuring the weekly water level and physicochemical parameters. The correlation concerning rainfall was plotted.
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Rainfall (a), Water level (b) and Electrical Conductivity (c) correlations in study wells
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| Spatial variation of maximum water level and minimum EC during wet season |
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Spatial variation of minimum water level and maximum EC during dry season
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By analyzing the EC data of 3000 wells located at the island along with the 3-years spatiotemporal variation data of 36 study wells, the freshwater zone distributions were identified using ArcGIS and Google Earth software.
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Spatial salinity distribution
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A monthly and annual water budget has been calculated for the identified freshwater zones (excluding EC areas) at Karainagar Island.
In our hydrogeological exploration at Karainagar, we conducted a comprehensive 2-D resistivity test to characterize the freshwater zone within the identified freshwater zone. By employing Electrical resistivity tomography (ERT) techniques, we aimed to delineate the spatial distribution of subsurface materials and identify potential freshwater lenses and its depth. The resistivity data obtained from the survey allowed us to create detailed profiles, highlighting variations in conductivity that could indicate changes in lithology and the presence of aquifers. The 2-D resistivity test is a powerful tool in our hydrogeological toolkit, aiding in delineating freshwater zones and enhancing our understanding of the complex subsurface hydrological environment in Karainagar.
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| Wenner array’s electrical resistivity value and pattern in measured and calculatedapparent resistivity Pseudo-sections and Inverse model section |
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| Geophysical survey at Karainagar |
Island-scale water balance development is underway to simulate groundwater behavior and predict future scenarios under various development and climate change scenarios. This could be applied to other adjacent islands located in Northern Sri Lanka.
Qualitative Approach:
Engaging citizens and other stakeholders in participatory groundwater monitoring, education, and the exploration of viable options for groundwater sustainability.
The well owners engaged in a participatory method to monitor their wells. Communicating this information with the community on an ongoing basis was the first step in villagers talking about their groundwater situation objectively. This then led to a serious dialogue and a better future through collaborative management of the resource. This approach engages local citizens in data collection while helping them internalize the issues, challenges, and solutions related to groundwater at Karainagar Island.  |
| The complexity of the “groundwater elephant” (source: MARVI). |
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| Well monitoring by villagers |
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One of the study well
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| Training workshop for community members |
Further, government departments and authorities were engaged in a series of governance workshops to implement a long-term sustainable water governance mechanism to protect the existing water resources and ensure their security.
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| Dissemination of research findings to the villagers |
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| Governance workshop for government stakeholders & community leaders |
Progress Presentation:
By the end of this research, the following outcomes are anticipated:
Comprehensive Hydrogeological Understanding: A detailed understanding of the groundwater dynamics (particularly freshwater), including discharge and recharge patterns, aquifer characteristics, and groundwater flow pathways.
Spatial Maps: Production of spatial maps depicting the spatiotemporal variation of groundwater levels and salinity, aiding in identifying vulnerable areas and freshwater zones.
Water Security Assessment: An assessment of water security on Karainagar Island, highlighting potential risks and vulnerabilities.
Modeling Scenarios: Development of models that simulate different scenarios, helping to predict future changes and devise adaptive management strategies.
Water governance and Policy Mechanism: As an output of this study, a policy brief will be developed, and the sustainable integrated water management plan will be implemented at the community level.
The study's findings will be valuable in various ways:
Water Resource Management:
Providing crucial insights to inform sustainable water resource management practices on the Karainagar and other adjacent islands.
Policy Recommendations:
Generating data-driven policy recommendations to address water security challenges on the island landscape.
Community Empowerment:
Empowering local communities with knowledge about their water resources, and promoting better conservation practices.
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| Status of a dug well |
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| Field data collection - Water level measurement and water sample collection |
