Multidisciplinary investigations of the transboundary dead Sea Basin and its water resources

Israel, the Palestinian Authorities and Jordan exploit the transboundary water resources of the Dead Sea basin. Our aim was to add reliable numbers to the water budget of the lake, despite the complicated integrative work and data acquisition due to the tense political situation. We here outline four parts of the project that generally concern surface and groundwater influx to the Dead Sea: (i) direct and non-direct measurements and hydrological modelling to quantify surface runoff, (ii) chemical fingerprinting to characterize groundwater origin, flow, and evolution between recharge and discharge areas, (iii) thermal remote sensing approaches to precisely identify location and abundance of groundwater discharge and (iv) groundwater modelling to quantify discharge volumes. The major outcomes are: (i) total mean annual runoff volumes from side wadis (except the Jordan River) entering the Dead Sea amounts to approximately 58-66 × 10⁶ m³ a^-1, (ii) area normalised recharge amounts differ on both sides being ~45 mm/a at the western side and ~32 mm/a at the eastern side, (iii) modelled groundwater discharge volumes from Upper Cretaceous aquifers from both sides are in order of magnitude of 177 × 10⁶ m³ a^-1.