Groundwater Resources in the Middle East

Transcription

1 An isotopic approach for elucidating the sources of nitrate and chloride contamination in the Mediterranean coastal aquifer: Implementation for the Gaza Strip Avner Vengosh

2 Groundwater Resources in the Middle East Saline inflows to the Sea of Galilee salinization salinization Fossil brackish groundwater Fossil groundwater

3 160 BAT YAM ASHDOD RISHON LEZIYYON PALMAHIM REHOVOT GIV'AT BRENNER Gedera Chloride distribution in pumping wells from the Coastal aquifer 130 Cl (mg/l ) BE'ER TUVEYA ASHQELON GEVAR'AM NIR AM Figure 1

4 Nitrate concentration (mg/l) A large-scale phenomenon: Nitrate pollution of groundwater from the Mediterranean coastal aquifer

5 . W Mediterranean Sea 200 m Sewage contamination B1 B2 A dunes Sea-water intrusion marine clays Coastal Plain aquifer Nitrogen leaching terrestrial clays (hamra) flow to the sea Calcareous sandstone (Kurkar) Recharge/irrigation of imported water leakage from adjacent aquifer and aquitrad unsaturated zone E Cenomanian/ Turonian Ecocene C D Intrusion Jaffa Formation of underlying Sayie Group saline groundwater marine clays and shales Km from coast 20 Schematic hydrogeological cross section

6 Sewage recharge BAT YAM RISHON LEZIYYON PALMAHIM REHOVOT GIV'AT BRENNER Gedera ASHDOD Oxygen isotope distribution in ground water from pumping wells from the Coastal aquifer (n=200) 130 BE'ER TUVEYA δ 18 O ( ה ) ASHQELON GEVAR'AM NIR AM Zohar Lake Volume of imported water ( MCM ) 0 to to to to Figure 2

7 Sea of Galilee -1 δ 18 O ( ) -2-3 waste water Yavne Be'er Toviyya Giva't Brener Gedera Revadim Hazor Chloride (mg/l)

8 Saline plumes in the inner parts of the aquifer are not derived from anthropogenic sources ASHDOD BAT YAM RISHON LEZIYYON PALMAHIM REHOVOT GIV'AT BRENNER Gedera 130 Cl (mg/l ) δ 11 B ( SRM-951) a 50 b 1/Boron (l/mmole) c 100 fresh water Sea of Galilee sewage-contaminated ground water sewage sea water ratio Figure 1 ASHQELON GEVAR'AM NIR AM BE'ER TUVEYA Be'er Toviyya Giva't Brener Gedera Hazor Yavne Revadim

9 mg/l 0 45 mg/l 0-45 mg/l mg/l > 85 mg/l Plume 7 Mediteranean sea Plume 9 Tel-Aviv Rishonletzion Mediterranean Sea Plume 6 Binyamina Hadera Natanya Sampling of 92 wells in the Coastal Plain aquifer 130 Ashdod Plume Ashkelon Plume Plume

10 Setting a threshold of δ 15 N=8 enabled us to distinguish between nitrate sources: >8 - manure and/or sewage <8 - natural soil nitrogen fertilizers Soil N manure and sewage δ 18 Ο (ΝΟ3) δ 15 Ν (ΝΟ3)

11 Integration of isotopic tools Nitrate pollution δ 18 O<-4 δ 15 N>8 δ 11 B >20 ; 3H> 10TU δ 18 O<-4 δ 15 N<8 δ 11 B >20 ; 3H< 10TU δ 18 O>-4 δ 15 N>8 δ 11 B <20 ; 3H> 10TU organic fertilizers/ animal manure natural nitrogen (old) domestic sewage

12 Integration of isotopic tools Salinization δ 18 O<-4 δ 11 B >40 ; 87 Sr/ 86 Sr < δ 18 O~-1 δ 11 B ~20 ; Br/Cl~3x10-3 δ 18 O>-4 δ 11 B <20 Br/Cl < 1.5x10-3 ; intrusion of underlying saline groundwater artificial recharge (Sea of Galilee) sewage

13 The Water Crisis in the Gaza Strip: Integration of Geochemistry, Numerical Modeling, and Policy Avner Vengosh 1, Erika Weinthal 2, Amer Marei 3, Alexis Gutierrez 4, and Wolfram Kloppmann 4 1. Ben-Gurion University, Beer Sheva, Israel 2. Tel Aviv University, Israel 3. Al-Quds University, West Bank 4. BRGM, Orleans, France EU Project (EVK1-CT ): Boron Contamination of Water Resources in the Mediterranean Region: Distribution, Sources, Social Impact, and Remediation (BOREMED)

14 Statement of the Problem The southern Mediterranean Coastal aquifer is a crossboundary aquifer, shared by the Israelis and Palestinians (Gaza Strip). In the Gaza Strip (30x12 km) groundwater is the only source of water for over a million people. Degradation of the water quality has created an ecological disaster.

15 Chloride distribution in groundwater of the southern coastal aquifer (summer 2000). 115 Sources: this study, PA water authority, Velder Israel EU, WHO Chloride (mg/l)

16 The Water Crises in the Gaza Strip Israel pumping 3.43% Population over 1.2 million Agriculture 90 MCM Domestic 50 MCM 34.5% 62% Data from UNEP Total annual consumption MCM

17 The Water Crises in the Gaza Strip 150 Water deficit 140 Natural replenishment Domestic 100 MCM/year 52 Anthropogenic Agriculture Lateral flow from east Data from UNEP 0 Recharge Consumption

18 The Crises after the Storm 4.5 Population (in millions) Estimate rate 70,000/year Current water deficit is ~23 MCM/y A major component of the recharge is water with low quality: high salinity and high nitrate pollution Year

19 A joint Israeli-Palestinian-French project Field work Inorganic constituents (Ca, Mg, Na, K, Sr, Cl, SO 4, HCO 3, NO 3, Br, and Al-Quds) Strontium, boron, oxygen isotopes (@BRGM) Nitrogen isotopes (University of Calgary, Canada) Numerical modeling Policy analysis

20 (ה) δ 2 H LMWL slope=5.6 The δ 18 O-δ 2 H slope of groundwater in the Israeli side and Gaza Strip is identical to that of the slope in groundwater from the adjacent Eocene aquitard GMWL (ה) δ 18 O

21 . Loess water extractions (batch) Loess leaching Sr/ 86 Sr Eocene Sr

22 115 Nitrate pollution of the Gaza Strip 110 GEVAR'AM YAD MORDEKHAY Brur Hail 105 NIR AM 100 Gaza Kfar Aza NAHAL OZ KEFAR DAROM

23 .. Gaza Strip δ 15 N (NO3) Nitrate (mg/l)

24 Gaza Strip 20 Nitrate fertilizers 15 δ 18 O (NO3) 10 5 NH 4 fertilizer Soil N manure and septic waste δ 15 N (NO3) Nitrate pollution by septic waste

25 The Geochemistry data Saline groundwater in Israeli territory originates from a mixture of saline groundwater flowing from the adjacent (Eocene) aquifer and leaching of overlying loess. This is a natural (geogenic) longterm process. Sources of salinization within the Gaza Strip include seawater intrusion and anthropogenic (nitrate) pollution, but the major source of salinity is the flow of the saline natural groundwater from Israel to the Gaza Strip. The salinization rate in the Gaza Strip has increased due to over pumping, lowering groundwater level, and intensification of the water gradients between Israel and Gaza Strip.

26 Sources of salinity in the Gaza Strip Sea water intrusion Saline groundwater from the eastern part of the aquifer (Israel) Anthropogenic sources (sewage effluents within the Gaza Strip) NW SE PA Israel Loess cover Mediterranean Sea meters Jaffa Formation (Sayie Group) ~ 20 km Eocene aquitard

27 MARTHE -A monolayer hydrodynamic two-dimension model Grid: square meshes of 500 m

28 Applying the MARTHE model in the Gaza Strip Simulated Chlo ride pat tern (MARTHE software) Water salinity components: 1. Northern, Cl=0 to 50 mg/l; 2. South-eastern, Cl=1500 mg/l; 3. Atmospheric, Cl=20 mg/l; 4. Ag return flow, Cl=300 mg/l Water balance: 1. Natural and induced recharge (within the Gaza Strip only) = 55 MCM/y 2. Pumping = 90 MCM/y

29 Management model 1. Reduce salinization by increasing pumping (x3~12 MCM/y) in the eastern side. 2. Decrease pumping within the Gaza Strip at the same magnitude (81 instead of 90 MCM/y). 3. Desalination of the pumped saline groundwater and supply to the Gaza Strip.

30 Water quality remediation upon increasing pumping along the border

31 Long-term implications 1. Improve the quality of water that is utilized the Gaza Strip (health aspects) 2. Remediation of the salinity problem in the Gaza Strip 3. Establish a mechanism of cooperation between Israel and the PA for mitigating the water crisis and lessen the political tension. In contrast to the classic upstream versus downstream situation, increasing pumping in the upstream (Israel, or along the border) will improve the water quality downstream (Gaza Strip). 4. Lack of cooperation will lead to ecological and social disaster in the Gaza Strip.