|M.Sc Student||Holtzman Ran|
|Subject||salinization Sources along the Lower Jordan River under|
|Department||Department of Agricultural Engineering||Supervisor||Professor Shavit Uri|
The Lower Jordan River, once a flowing freshwater river, is suffering from an ongoing reduction in the discharge and water quality. The severe reduction is caused by an excessive exploitation of its sources and diversion of sewage and agricultural drainage into the river. The extreme low flows and low water quality threaten the natural existence of the river and its potential use for agriculture. In spite of its importance, little research has been done in the river. The objectives of the study were to measure the discharge and water composition along the river and to evaluate the main sources that control its flow and chemical characteristics. The hypothesis of the study was that interaction with subsurface flows significantly affects the river flow and chemical composition. Note, that the reported study was conducted during draught conditions, thus representing base flows only. The research is based on a detailed field study, which included flow rate measurements in the river and its tributaries, water sampling and analysis and mass balance calculations of water and solutes. It was found that flow rate ranges between 500-1,100 L/s in northern sections and 300-1,650 L/s in the south. This low discharge represents a significant reduction from historical values and is lower than recent published estimations. Further decrease in flows and water quality will affect the ecological balance and the agricultural water use possibilities. Calculated mass balance of water flows shows that the subsurface source contributes to the river around 200-670 L/s (30-80% of the river flow). Calculations of solute balance show that the subsurface flows add 20-50% of the mass of solutes (e.g. SO4) that flows in the river. The results are consistent and agree with the geochemical and isotopic analyses. It is concluded that the impact of the subsurface component on the Jordan River is significant and must be taken into consideration, for future water management schemes and implementation of the Peace Treaty between Israel and Jordan.