Survey on the east bank of the Nile by the Sudan Archaeological Research Society between 1993 and 1996 was able to chart in detail changes in human settlement patterns. These reflect the political situation and developments in the agro-economy, but most importantly, fundamental changes in the hydrology of the Nile and in the local climate. In the Kerma periods the braided Nile channel was able to support a large population probably aided by greater local rainfall. With the demise of the eastern Nile channels and increasing aridity this population density became unsustainable and by the early 1st millennium bce the region, apart from the bank of the main Nile channel, was largely abandoned.