Arnon Karnieli, BGU University of the Negev, Israel
In ancient times as today, water management involved collection, transport, and storage. For harsh desert areas of less than 100 mm of rain, such as the Har HaNegev, collection of water to support drylands agriculture was the most important consideration. In this landscape rainfall runs off the surface largely unimpeded and collects in short-lived torrents that fill the wadis (ephemeral streams), so survival depends on the knowledge of how to harvest it. The hillside terraces (Fig. 1) consist of heavy stone walls built across the slope of a hill to capture both runoff water and eroded soils. In a variation of this technique, small dams were built across wadis (Fig. 1) for collecting runoff water from hillslopes and from occasional intensive floods in wadis. Such ancient agricultural systems in Har HaNegev cover more than 30,000 ha of cultivated plots, were dated as early as the Bronze and Iron Ages (ca. 4th to 1st millennia B.C.), expanded during the Nabatean and Roman (ca. 1st and 2nd centuries A.D.) periods, and ended during the Byzantine periods (3rd–6th centuries A.D.) period. The ancient agricultural fields were studied in Har HaNegev, specifically in the Avdat Farm, from their hydrological, geomorphological, and botanical aspects with specific attention to the mechanisms of conveying water into fields, the processes by which arable soil accumulated, and the nature of the agricultural crops grown.