Displacement of springs and changes in groundwater flow regime due to the extreme drop in adjacent lake levels: The Dead Sea rift (original) (raw)

Lake-level fluctuations brought on by climatic changes and anthropogenic factors may affect the flow regime in adjacent aquifers that discharge toward those lakes. Such fluctuations may also cause displacement of springs that discharge these aquifers. Using a calibrated numerical model, an extreme example of such phenomenon is observed in the Dead Sea rift valley and the adjacent Eastern Mountain Aquifer of the Judea and Samaria Mountains. Lake levels along the Dead Sea rift have changed dramatically and rapidly by hundreds of meters, followed by changes in the lake areas by hundreds of square kilometers. Simultaneously, the aquifer exhibited spring displacements, both on large and small scales. Currently, 50% of the aquifer water discharge in the Zuqim zone, and 10% north of the Dead Sea. But in the past, only 30% discharged at Zuqim and 40% north of the Dead Sea. There is evidence for such an occurrence in the past, and it is likely to recur in the future, based on the predicted progressive decline of the current Dead Sea level. This may have an impact on wetland habitats along the coast. 1.2. Lakes in the Dead Sea rift valley The Dead Sea (Fig. 1B) is the lowest terrestrial lake on Earth; its present level (2019) is −433 m above sea level (masl) (Israel Water Authority). It is a unique hyper-saline and deep terminal lake with a maximum depth of about 300 m. Its margin slopes are relatively steep, reflected in extreme lake-level fluctuations that follow climate changes or anthropogenic activity. The Dead Sea level currently falls at an average rate of > 1 m per year, mainly due to the damming of its