Temporal variability of sinkhole hazard illustrated in the western shore of the Dead Sea

The growing economic and societal damage caused by sinkhole activity worldwide requires the development of scientifically sound sinkhole hazard assessment approaches. Currently, there is a striking paucity of quantitative sinkhole hazard studies largely related to the incompleteness of sinkhole inventories and the lack of chronological data. Moreover, the probability of occurrence of sinkholes (i.e., sinkhole hazard) is commonly considered as a steady variable, a concept that may lead to significant hazard over- or under-estimates. The extraordinarily high frequency of sinkhole occurrence of the studied sector of the western shore of the Dead Sea has allowed us to explore for the first time the potential temporal variability of sinkhole hazard parameters. Here, we produced six multi-temporal sinkhole inventories with morphometric data between 2005 and 2021 using remote-sensed imagery. The frequency-size relationships generated for successive time intervals with a total of 667 new sinkholes reveal substantial temporal changes in the sinkhole hazard components (i.e., frequency and size). Moreover, the work illustrates that spatial redundancy (sinkholes nested within or intersecting pre-existing ones) can lead to significant hazard overestimates if not considered, especially in areas with high sinkhole density and clustering. This work discusses the limitations of some widely used methods and concepts for sinkhole hazard assessment and illustrates the advantages of detailed multi-temporal mapping for assessing frequency-size relationships and their temporal trends.