Lichtenberger et al. (2019) examined three soil profiles in Wadi Suf using OSL (Optically Stimulated Luminescence). They interpreted the profiles as showing that a shift from fluvial to colluvial deposition around A.D. 760 ± 40 due to a combination of climatic change and social disruptions (wars and plagues), together with failure of the slope-terrace system and associated irrigation due to shake and liquefaction caused by the 749 A.D. earthquake, together with loss of hinterland land management as agricultural demand from the city declined as a consequence of the same event.