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Accueil du site → Doctorat → Allemagne → 2006 → Locating zones and quantify the submarine groundwater discharge into the eastern shores of the Dead Sea, Jordan

Georg-August Universität zu Göttingen (2006)

Locating zones and quantify the submarine groundwater discharge into the eastern shores of the Dead Sea, Jordan

Akawwi, Emad Jalal

Titre : Locating zones and quantify the submarine groundwater discharge into the eastern shores of the Dead Sea, Jordan

Auteur : Akawwi, Emad Jalal

Université de soutenance : Georg-August Universität zu Göttingen

Grade : Doktorgrade der Mathematisch - Naturwissenschaftlichen 2006

Résumé partiel
This study aims to locate the zones of groundwaterdischarge into the eastern shores of the Dead Sea andto estimate its quantity. The evaluation of inflow wasaccomplished by different ways of approach : the firstone to use the electrical conductivity-temperature witha depth, the second to use a chemical tracer(Radon-222), the third to use thermal infrared imageryand the last is to use electromagnetic radiationtechniques in addition to the schematic geological andhydrogeological models of the study area.The Dead Sea divides into two layers relating to theelectrical conductivity and temperature with depth. Theupper layer subdivides into two members. The uppermember extends from the sea surface down to a depth of15-25 m. The lower member extends from a depth of 15-25m to 40 m and it characterized with high TDS and lowEC. The second layer extends from a depth of 40 m tothe end of profiles. Laboratory experiments carried outto find a relationship between the EC at a specific Tand the TDS. These experiments indicate that the ECreachs its maximal 202 mS/cm at a salinity of about 267g/l from where it starts decreasing with the increaseof the TDS and it reachs about 175 mS/cm at a salinityof 404 g/l. The minimal of TDS was observed at about460 g/l at EC about 156 mS/cm.The submarine groundwater discharged into the DeadSea in the upper 16 m in Sweimah area. It is dischargedin the upper 25 m in Zarka Ma in area, in the upper 15m in Zara and it is discharged in the upper 18 m inMujeb.The reason why the lower member has the highest TDSwas explained. It is due to the very high T at the DeadSea area in summer and very high evaporation. Thedensity of the upper layer becomes higher than that ofthe layer underneath. Therefore this denser upper layersinks beneath the layer which has lower density at thelayer where the groundwater discharged into the DeadSea and this last layer upwelling to the surface.The chemical tracer radon-222 technique shows thatthe highest radon concentrations were found at the areaclose to the shoreline. This means that the largestamount of groundwater discharge is close to theshoreline. As well the highest radon-222 concentrationswere found at a depth of 12 m in the three stationswhile it was at a depth of 7 m in the Zarka Ma instation. It shows also that the groundwater dischargsinto the Dead Sea in the upper 20 m. This is coincidingwith the finding from the EC and T survey. Thesubmarine groundwater discharge is estimated usingRadon-222 as 135.7 million m3/y in Sweimah area, about128.5 million m3/y at Zarka Main area, about 33.7million m3/y in Zara area and it is about 90.3 millionm3/y in Mujeb area. The total quantity of submarinegroundwater discharge into the eastern shoreline of theDead Sea is 388.2 million m3/y. The quatity ofgroundwater discharge is estimated by using mixing ofTDS about 181 MCM/y, and it is estimated about 59 MCM/yby using Darcys law. The results of SGD estimationsfrom different methods compared with the discharge fromwater balance 480 MCM/y. The results showed that thedischarge might be between 200 and 300 MCM/y.The thermal infrared imagery (TIR) was used toidentify thermal anomalies along the eastern shorelineof the Dead Sea, thereby to determine the exactlocations of submarine groundwater discharge.

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