The abandonment of the Decapolis region in Northern Jordan-forced by environmental change?

The Decapolis region in Northern Jordan flourished during the Roman, Byzantine and Umayyad period, leading to the construction of great monuments. They are very well preserved, because the region was abandoned in the 10th century AD and no significant resettlement took place. Earthquakes, diseases and political reasons are in general thought to be responsible for this development. However, rain-fed agriculture was the economic basis of the Decapolis cities, and only a surplus in production made their wealth possible. Thus environmental change, caused by mismanagement or climate change, could have been responsible for the abandonment of the area. Historical land use reconstruction and soil analysis are well-suited to prove environmental changes. Mismanagement should have left erosion on the plateau and colluvial substrates in the valleys, while a change of climate should be detectable in a differentiated soil genesis and indirectly by assessment of agricultural productivity of land use change. The analysis of the land use pattern and the study of soils at the Decapolis city of Abila indicate that a climate change had great influence in the abandonment of the site. In this context land use, soil development and local climate are important interrelated site factors.