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Former lakes and wetlands can provide valuable insights to the late Pleistocene environments encountered by the first humans to enter the Levant from Africa. Fluvial incision along Wadi Gharandal in hyperarid southern Jordan has exposed remnants of a small riverine wetland that accumulated as a sedimentary sequence up to ~20 m thick. We conducted a chronometric and sedimentological study of this wetland, including 10 optically stimulated luminescence dates. The wetland sequence accumulated during the period ~125 to 70 ka in response to a positive water balance coupled with a (possibly coseismic) landslide that dammed the outlet. The valley fill was dissected when the dam was incised shortly after ~36 ± 3 ka. Comparison of our ages with regional palaeoclimate indicates that the Gharandal oasis developed during the relatively humid Marine Isotope Stage 5. A minimum age of 74 ± 7 ka for two Levallois flakes collected from stratified sediments suggests that the oasis was visited by humans during the critical 130–90 ka time window of human migration out of Africa. Gharandal joins a growing network of freshwater sites that enabled humans to cross areas of the Levant and Arabia along corridors of human dispersal.

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Rapid urbanization and irrigation agriculture along the hyperarid Red Sea coastal plain in Egypt are dependent on freshwater supply from coastal aquifers. The aquifers are recharged by flash-floods from catchments (wadis) in the Eastern Desert, but large floods also cause infrastructure damage and deaths. Flood management strategies require knowledge of flood magnitude-frequency relationships, but in this regard quantitative data are lacking. Here, we reconstruct the peak discharge of a large flash-flood in 2016 using field measurements and flood discharge modelling along Wadi Umm Sidr, ~ 50 km west of Hurghada. In addition, we estimated the total flood volume, the flood duration, the infiltration rate and the transmission losses. Results are consistent with the few published determinations for large floods across the wider Levant. Field survey of recent floods (and palaeofloods) is a robust means to develop regionally applicable magnitude-frequency relationships. We close with some recommendations regarding flood protection of the Red Sea coastal infrastructure.

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