Tracing millennia-scale erosional and depositional dynamics in desert agriculture installations using high-resolution 3D data

Abstract

This paper follows a complete cycle of ancient desert agriculture in the arid Negev Highlands (NH), Israel. This cycle begins with pre-anthropogenic depositional and erosive processes the NH have undergone since the late Pleistocene, continues through the establishment of agricultural systems at the 3rd century CE, and ends with the restoration of erosion after the sites’ abandonment after 6-7 centuries of cultivation, till present days. Using two-millennia old markers and 10-year high-resolution 3D observations, this paper studies land process dynamics, compare long-term land degradation trends to recent ones, evaluate anthropogenic-induced influences, and follow the landscape evolution from the late-Pleistocene until present. Our results show 0.45 t ha⁻¹/yr erosion rate during the late-Pleistocene and most of the Holocene, prior to the anthropogenic intervention. This is evidence of the intensive soil erosion processes that governed the NH during that time. Furthermore, the paper shows erosion rates of 7.8 t ha⁻¹/yr over the last millennium and draw similarities to present ones. The results shed new light on long-term soil erosion process in desert environments and point to potential conservation strategies in similar regions. The time span of our study is uncommon and our evaluation offers a rare opportunity to analyze natural and anthropogenic effects on the environment.