干旱区生态环境知识资源中心

Recharge playas are prevalent throughout the hyper-arid southern Negev and Arava Valley of Israel. While some of these playas are terminal, others were found to be not absolutely terminal, allowing, under extreme floods, the outlet of water from their beds to a draining, ephemeral channel. Indicators for ancient to recent-past agricultural practicing were recorded for two playas. In one of them, this included the archaeological remains of seven Byzantine-Age stone terraces across the playa bed, indicating ancient runoff harvesting agriculture. In another playa, the agricultural indicator included observations by key informants who reported the cropping of barley and wheat by Bedouin populations until the mid-1990s. This was supported by rare bibliographic sources, reporting the cropping of cereals at this site by Bedouins during the 1930s and 1940s. Agro-hydrological assessments of seven playas and their catchments were conducted, revealing a marginal agronomic potential under the current climatic conditions and only for a small number of them. The results highlight the profound environmental know-how of local populations that inhabited this harsh region. Furthermore, the results coincide with previous studies, which have reported drier climatic conditions at present compared to those in ancient times, and even compared to those during the mid-1990s.