An Investigation into Control of Saltwater Intrusion Considering the Effects of Climate Change and Sea Level Rise

1. School of Engineering, Computing and Mathematics 20th- SWIM An Investigation into Control of Saltwater Intrusion Considering the Effects of Climate Change and Sea Level Rise Computational Geomechanics Group School of Engineering, Computing and Mathematics, University of Exeter, Exeter, UK. H. F. Abd-Elhamid A.A. Javadi H.F.Abd-Elhamid

2.  Saltwater intrusion problem  The main causes of Saltwater intrusion  The impact of climate changes and sea level rise on SWI  Measures to control SWI  The limitations of the previous methods to control SWI  The proposed methodology to control SWI  The objectives of 2D-FEST model  Model results  Conclusions School of Engineering, Computing and Mathematics 20th- SWIM Outline H.F.Abd-Elhamid

3.  Coastal regions (70% of population)  Population growth  Increase water demands  Increase the extraction from aquifers  Saltwater intrusion migration  Salinization (2-3%)  Abandonment of freshwater supply  SWI control Saltwater Intrusion H.F.Abd-Elhamid

4. The main causes of Saltwater intrusion 1- Human activities - Over-pumping 2- Natural events - Climate changes - Sea level rise - Tides Climate change - Human activities (global worming) - Natural changes (volcanoes, sun) Sea level rise - Thermal expansion of seas & oceans - Melting of glaciers and ice caps - Melting of Antarctic ice sheets H.F.Abd-Elhamid

5. http://whyfiles.org Estimation of sea level rise - Last Century (10-20) cm (IPCC1996) - Current Century (20-88) cm (IPCC2001) The combined impact of sea level rise and over-pumping on SWI H.F.Abd-Elhamid

6. 1.Reduce pumping rates. 2. Relocate pumping wells. 3. Subsurface barrier 4. Natural recharge 5. Artificial recharge (injection wells) 6. Extraction wells Measures to control Saltwater Intrusion H.F.Abd-Elhamid

7. 5- Artificial recharge (injection wells) - Surface spread (unconfined) -injection wells(confined) - Injected water may be from (surface water, ground water, treated waste, desalinated seawater.) 6- Extraction wells - Extract brackish water - Dispose it to the sea H.F.Abd-Elhamid

8. The limitations of the previous methods to control SWI •  Short term solution (population growth) Not efficient for deep aquifers • Availability of fresh water for recharge • The cost of Fresh water • Using treated waste water for recharge • Using desalinated sea water for recharge Disposal of brackish water to the sea and the effects on marines, fishing and tourism  Sea level rise due to climate change not considered H.F.Abd-Elhamid

9. The proposed methodology (ADR) 1-(A)Abstract brackish water 2-(D) Desalinate brackish water using (RO) 3-(R) Recharge the desalinated brackish water (part) Advantages 1- Increase fresh water storage 2- Decrease saline water volume 3- Control saltwater intrusion 4- Increase water resources Overcomes shortcomings of previous methods - RO: availability and cost of fresh water -Recovery rate (70-90%) -Disposal of brine (30-10%) H.F.Abd-Elhamid

10. Develop a coupled transient finite element model for computing solute transport through saturated/unsaturated soils. Study saltwater intrusion of miscible solute transport (density-dependant) Use the developed model predict the extent and solute concentrations Study the effect of sea level rise due to climate change on saltwater intrusion for the current century (IPCC 2001). Use the developed model to study the control of saltwater intrusion using different scenarios. Study the efficiency of the proposed methodology to provide a new source of water for coastal regions. The objectives of the 2D-FEST Model H.F.Abd-Elhamid

11. Aw Rw Sea D Brackish water Fresh water L The steps of the proposed project 1- Simulate SWI and predict salts extent and concentrations 2- Simulate the effect of sea level rise due to climate changes (20-88 cm/century) 3- Simulate different scenarios to control SWI (Recharge wells - Abstraction wells - Combination of Abstraction Recharge wells) 4- Simulation - Optimization (location – depth - rates) H.F.Abd-Elhamid

12. Model results • 2D-FEST Model • Henry (1964) H.F.Abd-Elhamid

13. Model results • 2D-FEST Model • Henry (1964) H.F.Abd-Elhamid

14. Sea level rise 10% 20% H.F.Abd-Elhamid

15. Model results • 2D-FEST Model • SUTRA Code • - INTERA Code • Henry (1964) H.F.Abd-Elhamid

16. Conclusions • The developed coupled transient finite element model gave good results to predict the extent and solute concentrations in coastal aquifers. • The developed model can be used to Study saltwater intrusion of miscible solute transport (density-dependant). • The developed model can be used to study the effects of sea level rise on saltwater intrusion. Future (cont. current) work • Use the developed model to study the control of saltwater intrusion using different scenarios. • Simulation - Optimization models. • 21th SWIM. H.F.Abd-Elhamid

17. School of Engineering, Computing and Mathematics 20th- SWIM Thanks Q & A H.F.Abd-Elhamid