Isr. J. Earth Sci.; 57: 199–211 DOI: 10.1560/IJES.57.3–4.199 © 2008 Science From Israel/ LPPLtd. 0021-2164/08 $4.00 E-mail: dodik@bgu.ac.il Late Quaternary deposition and erosion processes along the margins of the Yamin Plain, northeast Negev, Israel Avraham Dody, a Ariel Nahlieli, b Yoav Avni, c Hai Cohen, b David Weiner, a and Naomi Porat c a NRCN, P.O. Box 9001, Be’er Sheva 84190, Israel b Department of Geography and Environmental Development. Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel c Geological Survey of Israel, 30 Malkhe Yisrael Street, Jerusalem 95501, Israel (Received 22 September 2008; accepted in revised form 28 April 2009) ABSTRACT Dody, A., Nahlieli, A., Avni, Y., Cohen, H., Weiner, D., and Porat, N. 2008. Late Quaternary deposition and erosion processes along the margins of the Yamin Plain, northeast Negev, Israel. Isr. J. Earth Sci. 57: 199–211. This study presents rates of accumulation and transport of sands as well as rates of incision along the margins of the Yamin Plain, northeastern Negev, and evaluates the stability of the present landscape. Geomorphological mapping, OSL and 14 C dat- ing, and sedimentological analyses suggest that rates of erosion range between ~45 mm/year in the eastern side of the study area and 0.05 mm/y on the western side. The calculated erosion rates show that, until recently, geomorphic processes in the eastern part of the plain were dominated by accumulation of sands derived from the Hazeva Group. However, accelerated erosion is observed near the contact between the sand units and the carbonate bedrock of the Judea Group. It appears that the area west of the plain has been stable during the last glacial (circa 73–18 ka). We suggest that the exclusion of domestic grazing from the Yamin Plain in the 1950s changed the balance between erosion and sedimentation and caused accelerated erosion mainly in the east- ern part of the Yamin Plain by decreasing infltration and increasing runoff. INTRODUCTION The national site for near-surface radioactive waste disposal is located in the Yamin Plain (YP). The waste contains very low activity but long-lived radioactive materials. A previous study (Dody and Weiner, 2005) showed that the groundwater in the local aquifer near the base of Hazeva Formation (80 m depth) is very old with no evidence for present-day recharge. In addition, Dody et al. (2006) performed laboratory experiments that indicate negligible uranium migration in sandy soil similar to the soils exposed in this plain. The joint conclusion of these studies is that no signifcant present recharge or radionuclide transport towards the aquifer is expected. If this conclusion holds, surface processes such as erosion are the predominant concern for near- surface waste disposal. The main objective of this study was to evaluate erosion rates in the Yamin Plain. Drainage in arid environments is generally char- acterized by fash foods that cause large changes in channel patterns over short periods of time. However, studies on sandy soils in arid environments (Eldridge