Historic desertification

Heavy downpours resulting in flash floods wash away sediment and there seems to have been an increased number of extreme events in the Levant at the end of the Byzantine period.

It was assumed that population growth or conquest by nomadic tribes led to over-exploitation of the land, leading to soil erosion and irreversible degradation.

On the contrary, a high fire risk emerged since pine trees are easily flammable, and the grazing pressure was moved towards more sensitive areas in the desert belt.

[2] A number of running research projects in Jordan found that the erosion of the main agricultural soil, the Terra Rossa, took place at the end of the last ice age and during the Younger Dryas.

In this context, soils and colluvia point to an increased frequency of extreme rainfall events in the Levant at the end of the Byzantine period.