Is the Dead Sea dying?

Transcription

1 Is the Dead Sea dying? Many slides in this presentation are based on work done by the Israeli Geologic Survey (see symbol in the left corner) under the direction of Dr. Ittai Gavrieli. He and his team have done much to expand the knowledge base of the Dead Sea hydrology, chemistry and stratification dynamics Historical water level changes, Anthropogenic intervention and outcome, The Peace Conduit; a solution or a new problem? Modeling the Dead Sea. Scott Wells, Portland State University CBS 2:45

2 N The Dead Sea

3 The Dead Sea

4 The Dead Sea Israel/West Bank/Jordan Inflows: Jordan River, saline and freshwater springs, return brines from mineral processing Outflows: evaporation, pumping for mineral processing

5 The Dead Sea Limnology: Hypersaline terminal lake Lake level: 2005: ~418m below mean sea level 2016: -429 m Chemistry: Na, K, Cl, Ca, Mg, HCO3, SO4, Br; TDS=345 g/l Physiography: A= 635 km2, V=135 km3 Maximum Depth: 312m. N-S length is about 70 km E-W length is about 15 km Climate: Mediterranean Semiarid

6 The Dead Sea catchments area: 43,000 km 2

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8 Dead Sea water levels Recent water level drop: ~1 m/yr Present water level: -429 m

9 Dead Sea water level since 2000BC (Ken-Tor et al., 2002)

10 Beginning of the 20 th century Inflows: MCM Losses: MCM Beginning of the 21 st century Inflows: 400 MCM Losses: 1050 MCM Evaporation from DS surface: ~800 MCM Evaporation from evaporation ponds: 250 MCM

11 Annual deficit: > 650 MCM

12 -392 m.s.l

13 -398 m.s.l

14 -410 m.s.l

15 -450 m.s.l

16 Results to date A shrinking lake Beginning of the 20 th century Dead Sea Level: -390 m Surface area: 950 km 2 Volume: 155 km 3 Beginning of the 21 th century Dead Sea Level: -415 m Surface area: 650 km 2 Volume: 135 km 3 Massada 0 5 k m

17 Exposure of large mudflats - safety problem Inaccessible shorelines

18 Sinkhole formation

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20 Lowering of the drainage base- led to infrastructure collapse

21 Future water level of the Dead Sea as a function of inflows Input (10 m ) ? Time (yr)

22 Predicted Dead Sea area based on model Massada 0 5 km

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24 How to save the Dead Sea? Current situation result of human intervention in the water balance of the system Changing this situation requires a new intervention If there is an intervention, will it introduce new and undesired effects?

25 Alternatives No intervention Restoring past conditions (~1800 MCM freshwater inflow) from Jordan River Construction of the Peace Conduit from the Gulf of Eilat to the Dead Sea

26 Peace Conduit

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29 Valley of Peace Video

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32 Pre-feasibility study (Harza JRV) Pumping of 1800 MCM/yr from the Gulf of Eilat Production of 800 MCM of desalinized water Discharge of 1000 MCM/yr reject brine to the Dead Sea Length of Conduit: 180 km Estimated costs: $5-6 billion

33 Supposed Benefits of the Peace Conduit Raising and stabilizing the Dead Sea level. Put an end to the collapse of the infrastructure around the lake Enable sustainable development Restore the attractiveness of the area Utilize the 400 m elevation difference for desalinization of seawater Strengthen peace in the region

34 Mixing of seawater in the Dead Sea Expected outcome: Change in the Dead Sea composition. Precipitation of gypsum (CaSO 4 2H 2 O). Stratification of the water column. Microbial blooming in the upper water body. Development of anoxic condition in the lower water body [?]

35 Another possible outcome No longer will people be able to float like penguins! stratification

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37 A Dynamic Limnological Model for the Dead Sea Provide a long-term (decades) forecast for the processes and changes in the Dead Sea due to seawater inflow. Serve as a tool for the proper planning of the Peace Conduit Become an operational tool for the management of the Dead Sea under controlled seawater inflow rate and steady state level.

38 Modeling of the Dead Sea Nadav Lensky, Yona Dvorkin, Vladimir Lyakhovsky, Scott Wells, Isaac Gertman, Boris Krumgalz, Ittai Gavrieli Evaporation rate Saturation / Thermodynamics Energy balance Oceanographic / Limnological models (1D, 2D, 3D) Chemical composition Inflows (seawater & freshwater) Equation of State

39 Hydrographic profiles Meteorological Bouy

40 Temperature variations during 1998 at different depths Temperature (C) Upper layer during summer m 20 m 30 m J day Winter cooling Beginning of overturn Complete overturn

41 Annual salinity profiles Salinity (sigma 25) y Februar 08, March 14, May 16, July 30, October 15, December 24,

42 Temperature and Salinity Modeling 1-D POM 2-D CE-QUAL-W2 3-D POM sigma-stretched grid vs z- coordinate grid

43 Model unique theoretical issues Compressibility Equation of state based on chemical components and temperature rather than salinity and temperature Evaporation Chemistry Na, K, Ca, Mg, Cl, Br, SO 4, HCO 3 Precipitation of halite, gypsum, carnallite (KMgCl 3 6H2O) Growth of algae and bacteria as a function of salinity

44 Dead Sea Grid CE-QUAL-W2 1 km X 1 m grid 70 km vs about 300 m The Dead Sea, Israel/J Project Funded by Israeli G

45 1E+004 1E+005 1E+006 1E+007 1E+008 1E+009 1E+010 1E+011 1E+012 Volume, m3 Dead Sea Grid -300 Volume-elevation for Dead Sea, Israel-Jordan -400 Topographic volume-elevation CE-QUAL-W2 model grid -500 Elevation, m

46 Modeling Results Temperature structure of Dead Sea Temperature profile Contour side view Impact of return Dead Sea brine Precipitation of halite

47 12/31/97 2/14/98 3/31/98 5/15/98 6/29/98 8/13/98 9/27/98 11/11/98 12/26/ Algae Biomass Predictions W2 model Density Algae biomass, mg/l Density, kg/m 3 1 m depth Modeling Results Red Sea Algae biomass, mg/l m depth Inflow Algae Algae biomass, mg/l m depth 0 growth Algae biomass, mg/l E-005 6E-005 4E-005 2E m depth Julian day

48 Field Work in the Dead Sea

49 Main Conclusion