Archaeogeophysical and satellite image investigation of Early Bronze- and Iron Age water management structures at Bisya, Oman

Studies of the location, function, and chronology of ancient hydraulic systems are crucial to understanding human adaptation to arid lands. Integrated archaeogeophysics are essential methods to document these buried, little visible and very extended structures. Such systems for water catchment and management (e.g., aflaj) were likely used for irrigation and made it possible to maintain sustainable occupation from the earliest oasis sites until recent times.

Here we report on archaeogeophysical field investigation that was carried out near Bisya, Oman, where two major wadis converge in a plain that had been a fertile oasis at least since the Bronze and Iron ages until the Islamic period. The first implementation, extent and chronology of such water management system is still little known, as well as the functional purpose of different identified round structures, especially in relation to the known decline in water abundancy in various historical periods.

At Al-Dhabi site, a discovery of ditches was made with Geomagnetics and Georadar, later confirmed by excavations. At Fell site, a channel could be identified by Georadar. Geomagnetics revealed the existence of an elongated structure with one circular side, further connected channels and a second area twice encircled by magnetic anomalies. At Salut site, Geomagnetics confirmed the existence of ditches, that surround the elliptical structure, and a strong anomaly indicates the location of the central well. All anomalies are related to the contrast between the formerly water-logged fine sediments in the channels and ditches, the bulding material of deteriorated mud bricks and calcrete rocks.