Vulnerability of tourism development to salt karst hazards along the Jordanian Dead Sea shore

Abstract. The Dead Sea shore is a unique young and dynamic evaporite karst system. It started developing in the 1960s, when the main water resources that used to feed the terminal lake were diverted towards deserts, cities and industries. The Dead Sea water level started to lower at an accelerating pace, exceeding 1 meter per year during the last decade, causing a hydrostatic disequilibrium between the underground fresh waters and the base level. This battery-like system provides the energy needed for the development of underground cavities, hectometre-size landslides, and vertical erosion of channels during flash-floods. The geological discontinuities are the weakest points where the system can re-balance and where most of the energy is dissipated through erosional processes. Groundwater is moving rapidly along these discontinuities to reach the dropping base level. The salt that soars the sediments matrix is dissolved along the paths favouring the development of enlarged conduits, cavities, and the proliferation of ground collapses (sinkholes). Despite these unfavourable environmental conditions, large touristic projects have flourished along the northern coast of the Jordanian Dead Sea. In this work, thanks to the application of remote sensing techniques combined with repeated field observations, we show that a 10 kilometres-long strip of land along the Dead Sea shore that encompass several touristic infrastructures is exposed to subsidence, sinkholes and landslides. Furthermore, we point out the importance of setting up an early warning system to warn the authorities prior to the triggering of hazardous events, limiting or preventing possible disastrous consequences related to hydrogeological hazards.