Wasim Ali

Erratum: Impact of managed aquifer recharge on the chemical and isotopic composition of a karst aquifer, Wala reservoir, Jordan

Storm-water harvesting and storage via managed aquifer recharge (MAR) is a promising approach to combat water scarcity in semi-arid regions, but poses a challenge for karst aquifers and regions with highly variable water availability. The infiltration of low-mineralized surface water and its impact on highly mineralized groundwater of a karst aquifer was investigated at Wala reservoir in Jordan over a period of approximately 10 years. The results show significant groundwater-level rise in a wellfield, in response to the yearly average infiltration of about 6.7 million m3. This corresponds to about 60 % of the yearly average abstraction of about 11.7 million m3, confirmed by mixing calculations with tritium. A decreasing trend in infiltration due to sedimentation is observed. Mean groundwater residence times of several thousand years, derived from carbon-14 dating, indicate a large storage capacity of the aquifer. The heterogeneous distribution of the residence times is caused by strong groundwater withdrawals and artificial recharge along with karst-specific aquifer characteristics. Temporal groundwater salinity fluctuations in the wellfield are observed after the first MAR infiltration. Enhanced groundwater flow along the wadi course was demonstrated, which is an important aspect with regards to future MAR projects in similar wadis of the region.

Sulphur and oxygen isotopic characters of dissolved sulphate in groundwater from the Pleistocene aquifer in the southern Jordan Valley (Jericho area, Palestine)

Sulphate and chloride concentrations in the shallow Pleistocene aquifer systems in the lower Jordan valley area indicate a general trend of increasing salinity eastward and southward. This study was conducted in one of the important sub-basins feeding the Pleo–Pleistocene aquifer in the Jericho area in the southern part of the valley using S and O isotopes of dissolved sulphate. The results show that sulphate has mainly two contributions to the groundwater. One is the surface seepage, which is present as a salty leachate form with the positive δ34Ssulphate values of primary gypsum in Lisan and Samara formations, and the second is the upwelling saline water which was in contact with a deep secondary gypsum, aragonites and salty rocks and rose up under heavy abstraction with depleted 34S in sulphate and relatively high sulphate and chloride content. The latest was clearly shown in the Arab Project wells to the east that is undergoing a continuous heavy abstraction. The isotopic signatures of S and O in these wells to the east show that this depleted 34S and highly concentrated sulphate might also indicate a dissolved sulphate originating from pyrite oxidation that results from the interaction with a pyrite-rich aquifer, which can well up with salty water under heavy abstraction and is oxidised in the upper aerobic shallow aquifer.

Challenges of Implementing IWRM in the Lower Jordan Valley

The Lower Jordan Valley in the Middle East comprises parts of Israel, Jordan and the Palestinian Territories and is amongst the water scarcest regions worldwide. As the average water availability per person is below 150 m³/year, this region is facing absolute water scarcity. The water resource systems are overexploited and subject to further stress through high population growth, climate change and the recent migration of refugees from Syria. Declining water levels of the Dead Sea and within the regional aquifers are visible evidence of overexploitation. Further, salinization and contamination including pharmaceutical residues in surface and groundwater indicate the strong deterioration of water quality by anthropogenic activities. Integrated Water Resource Management (IWRM) is a concept to address these water related issues but needs to be incorporated into the water strategies of the riparian states. SMART (Sustainable Management of Available Resources with Innovative Technologies) is a research and development project within the framework of IWRM and has the overall goal to develop a transferable concept for a sustainable water resource management in the Lower Jordan Valley. Besides natural available freshwater, unconventional sources such as treated waste water, artificially recharged groundwater, and desalinated brackish groundwater are considered. Based on detailed water balances, management concepts have been developed and applied to allow the assessment of the current state of the water resources, as well as the future development, taking the actions of the respective water strategy into account. The SMART approach is transferable to other regions in the world suffering under natural and/or manmade water scarcity.

Hydrogeological Investigations in the North-Eastern Dead Sea Area, Suweimeh, Jordan

The Sweimeh Area at the north-eastern shoreline of the Dead Sea represents the margin between the Jordan Valley to the west and the escarpment of the Jordan mountains to the east. This study is a part of the activity of the Karlsruhe team within the course of the Multinational BMBF Joint Research Project Water Resources Evaluation for a Sustainable Development in the Jordan Rift Basin as part of the German — Israeli — Jordanian — Palestinian Joint Research Program, 2nd Phase