Floodplain degradation and settlement history in Wadi al-Wala and Wadi ash-Shallalah, Jordan

Abstract

This study investigates a Mid-Holocene cycle of stream aggradation and incision in Wadi al-Wala and Wadi ash-Shallalah, western Jordan. Aggradation took place sometime between 7 ka and 6 ka, followed by stability as evidenced by a floodplain soil that was mantled by colluvial deposits between 4.6 and 4 ka. Stream incision around or after 4 ka eroded the floodplains. A second cycle of aggradation and incision occurred in the late Holocene, but this cycle is not synchronous between the two streams. Causes of the stream incision around 4 ka are hypothesized in the context of local geomorphological and hydrological characteristics, regional climatic change, Dead Sea level changes, and cultural landscape changes interpreted from archaeological and pollen records. In the context of available local and regional evidence, this study discusses the relation between Early Bronze Age settlement and stream degradation.