Water Resources Management within the context of Climate Change: The Case of a Small Island...

Water Resources Management within the context of Climate Change:

The Case of a Small Island Developing State (SIDS)

Geoffrey MarshallHydrogeologist

Water Resources Authority Jamaica

04/21/23 Presentation at a workshop on “Challenges and Opportunities in Climate Change Adaptation for the Water Sector: Elements for a Regional Agenda”

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Location


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Water Resources of Jamaica

• Island divided into 10 hydrologic basins• Hydrostratigraphy determines the water

type• Primary supply is from ground water

sourced from limestone aquifers-western two thirds of the island

• Eastern one third of the island has an abundance of surface water resources i.e. rivers and streams.


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Hydrostratigraphy


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Well and River Locations


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Groundwater Monitoring

Total-282: Limestone Aquifer-191: Alluvium aquifer-91


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Surface Water monitoring

Total monitoring points-117—R-52 (Loggers-27); NR-43; Spot-22


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Jamaica-Groundwater Pollution Monitoring


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Water Availability and Use

Exploitable Groundwater

• Limestone Aquifer---3281.85 MCM/yr

• Alluvium Aquifer----- 136.75 MCM/yr

Total-------------------3418.60 MCM/yr

Surface water

Total-------------------- 664.9 MCM/yr


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Water –Used/Unused

Used

• Groundwater-----------840.5 MCM/yr

• Surface water---------- 76.5 MCM/yr

• Total---------------------917.0 MCM/yr

Unused Reliable Yield

• Groundwater----------2579.3 MCM/yr

Surface water----------- 592.6 MCM/yr

Total---------------------- 3171.9 MCM/yr


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Vulnerability of SIDS

• Small but rapidly increasing populations

• Strongly impacted by tropical storms/hurricanes.

• High variability in precipitation patterns

• Caribbean Tectonic Plate with implications for earthquakes and tsunami


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Vulnerability of SIDS• Geology and topography which

influence rainfall, stream and karstic basin flooding and landslides

• Hydrostratigraphy which influence the location and extent of aquifers and aquicludes and together with the spatial and temporal distribution of rainfall determine water availability


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Importance and Significance of Water in SIDS

• SIDS rely on any or all of groundwater, surface water or rainfall (depending on size and topography).

• Input for all natural water resources is precipitation.

• Changes in precipitation patterns would have a significant effect on water resources recharge/storage and availability.


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Interconnection with Water Resources

• Energy and food security, environmental sustainability, economic development all depend on a reliable water supply.

• Solutions for these issues, if conceived in isolation without considering climate change impacts on water will be self-defeating.


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Climate Change Scenario Analysis in Jamaica

• High Probability that temperatures will increase, based on general results from GCMs.

• Most GCM models show decrease in precipitation by 2050 peaking in 2080, though magnitude varies from model to model.

Threats to Water Sector from Climate Change

• Longer and more intense dry season

• Increase in frequency of high intensity rainfall-increased flooding and landslides

• Watersheds-poor agricultural practices increase vulnerability-increased erosion and turbidity of streams

• Agriculture especially non-irrigated will be severely impacted

• Sea level rise-coastal flooding/higher storm surges will affect coastal aquifers.


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Adapting Water Resource Management to Climate Change

• Both Mitigation and Adaptation methods needed, with more emphasis on Adaptation.

• Strategies are needed at the local, regional and national levels.


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Options to reduce Water Sector Vulnerability to Climate Change

• Increase and maintain investment in hydrological data collection and monitoring.

• Fund research into adopting planning methods for water resources and supply.

• Develop appropriate modeling tools to assist strategic planning of resources.


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Options, continued

• Develop national flood risk mapping to support emergency operations and land use planning.

• Support and fund increased water use efficiency across all water use sectors.

• Merge government agencies responsible for land and water management.


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Society’s Response

• Solutions to these water problems lie with decision makers in other parts of society.

• Need for understanding of water issues and “outside-the-box” thinking to implement adaptation measures.


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Conclusions

• Keyword for adapting to impacts of climate change on water resources is ‘resilience.’

• Priority should be “no-regret” and “low-regret” measures.

• Increased/improved water resources monitoring cannot be over-emphasized. More financial support must be provided for this.

Water Resources Management within the context of Climate Change: The Case of a Small Island...

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