School of Engineering 20 th SWIM Computing and

  • Slides: 17
Download presentation
School of Engineering, 20 th - SWIM Computing and Mathematics An Investigation into Control

School of Engineering, 20 th - SWIM Computing and Mathematics 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, UK. H. F. Abd-Elhamid A. A. Javadi H. F. Abd-Elhamid 20 th-SWIM 1

School of Engineering, 20 th - SWIM Computing and Mathematics Outline Saltwater intrusion problem

School of Engineering, 20 th - SWIM Computing and Mathematics Outline 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 2 D-FEST model Model results Conclusions H. F. Abd-Elhamid 20 th-SWIM 2

Saltwater Intrusion Coastal regions (70% of population) Population growth Increase water demands Increase the

Saltwater Intrusion 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 H. F. Abd-Elhamid 20 th-SWIM 3

The main causes of Saltwater intrusion 1 - Human activities - Over-pumping 2 -

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 20 th-SWIM 4

Estimation of sea level rise - Last Century (10 -20) cm (IPCC 1996) -

Estimation of sea level rise - Last Century (10 -20) cm (IPCC 1996) - Current Century (20 -88) cm (IPCC 2001) http: //whyfiles. org The combined impact of sea level rise and over-pumping on SWI H. F. Abd-Elhamid 20 th-SWIM 5

Measures to control Saltwater Intrusion 1. Reduce pumping rates. 2. Relocate pumping wells. 3.

Measures to control Saltwater Intrusion 1. Reduce pumping rates. 2. Relocate pumping wells. 3. Subsurface barrier 4. Natural recharge 5. Artificial recharge (injection wells) 6. Extraction wells H. F. Abd-Elhamid 20 th-SWIM 6

5 - Artificial recharge (injection wells) - Surface spread (unconfined) - injection wells (confined)

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 20 th-SWIM 7

The limitations of the previous methods to control SWI Short term solution (population growth)

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 20 th-SWIM 8

The proposed methodology (ADR) 1 -(A) Abstract brackish water 2 -(D) Desalinate brackish water

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: RO availability and cost of fresh water - Recovery rate (70 -90%) - Disposal of brine (30 -10%) H. F. Abd-Elhamid 20 th-SWIM 9

The objectives of the 2 D-FEST Model n Develop a coupled transient finite element

The objectives of the 2 D-FEST Model n Develop a coupled transient finite element model for computing solute transport through saturated/unsaturated soils. n Study saltwater intrusion of miscible solute transport (density-dependant) n Use the developed model predict the extent and solute concentrations n n n 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. H. F. Abd-Elhamid 20 th-SWIM 10

The steps of the proposed project 1 - Simulate SWI and predict salts extent

The steps of the proposed project 1 - Simulate SWI and predict salts extent and concentrations Aw 2 - Simulate the effect of sea level rise due to climate changes (2088 cm/century) Rw Sea 3 - Simulate different scenarios to control SWI (Recharge wells Abstraction wells - Combination of Abstraction Recharge wells) D Brackish water Fresh water L 4 - Simulation - Optimization (location – depth - rates) H. F. Abd-Elhamid 20 th-SWIM 11

Model results - 2 D-FEST Model - Henry (1964) H. F. Abd-Elhamid 20 th-SWIM

Model results - 2 D-FEST Model - Henry (1964) H. F. Abd-Elhamid 20 th-SWIM 12

Model results - 2 D-FEST Model - Henry (1964) H. F. Abd-Elhamid 20 th-SWIM

Model results - 2 D-FEST Model - Henry (1964) H. F. Abd-Elhamid 20 th-SWIM 13

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

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

Model results - 2 D-FEST Model - SUTRA Code - INTERA Code - Henry

Model results - 2 D-FEST Model - SUTRA Code - INTERA Code - Henry (1964) H. F. Abd-Elhamid 20 th-SWIM 15

Conclusions n The developed coupled transient finite element model gave good results to predict

Conclusions n The developed coupled transient finite element model gave good results to predict the extent and solute concentrations in coastal aquifers. n n 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 n Use the developed model to study the control of saltwater intrusion using different scenarios. n Simulation - Optimization models. n 21 th SWIM. H. F. Abd-Elhamid 20 th-SWIM 16

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

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