This landscape survey of the Balikh Valley in Syria straddles the limit of rain-fed cultivation. Features such as canals, low density “field scatters,” smaller sites, ancient roads, and relict river channels enable the boundary between ancient rain-fed cultivation and irrigation to be approximated. By coupling the evidence from such features with archaeological site survey, I suggest that water supply in the Balikh River constrained total settlement, and therefore population, to a limited size. During the phase of nucleated Early and Middle Bronze Age settlement, nodal settlements formed a focus for the limited pattern of irrigation canals. Settlement patterns dispersed during the later Bronze Age and Iron Age, and the landscape started to fill with numerous smaller settlements. In the Hellenistic/Roman period a major canal probably supplied much of the central Balikh Valley with irrigation water. During this phase region-wide canal systems apparently dictated the settlement pattern, which in certain cases spread out into formerly unirrigated areas away from the immediate alluvial plain.
T. J. Wilkinson (Thu,) studied this question.