Geomorphology of paleokarst sinkholes in arid and semi-arid zones (Case study of Diab doline in El-Galala El-Bahariya Plateau, Egypt)

Karst phenomena are crucial in physical geography due to their reliance on field studies. There's significant interest in limestone sinkholes in semi-arid environments, as they pose a major hazard to urban and infrastructure development, seen in areas like the Dead Sea coastlines and Florida, USA.

Egypt's El-Galala El-Bahariya Plateau, a semi-arid region, exhibits rocks affected by dissolution from groundwater and rainwater, along with chemical reactions impacting calcium carbonate. Satellite imagery of this area revealed a large, collapsed dissolution sinkhole. Field studies confirmed its location at about 700 meters above sea level, 3.25 km west of Porto Sokhna resort, and 4 km southeast of Galala city.

This sinkhole features a semi-circular opening with a diameter of roughly 30 meters and a similar depth, capable of accommodating a 10-story building with a volume of 21,195 cubic meters. The research explored the natural characteristics, factors influencing karst erosion, formation and development processes, and the resulting risks in arid and semi-arid environments, concluding with findings and recommendations.

Keywords: Karst Phenomena, Melting Hole, Diab Doline, Arid Zones, El-Galala El-Bahariya Plateau