Monitoring sand dune stabilization along the coastal dunes of Ashdod-Nizanim, Israel, 1945-1999

摘要

Temporal changes in the stabilization process along the coastal dunes of Israel were assessed using a series of 23 aerial photographs taken over the period 1944-1999. The stabilization rate was then quantified using a specially developed method for the calculation of sand dune movement and by the calibration of the gray-scale images into vegetation cover maps. An episodic reactivation of the dunes during the 1970s was identified and examined with respect to various physical and human factors. The Mediterranean climate along the coast of Israel and the low wind energy are favorable for the stabilization of sand dunes in the absence of human activity. It was shown that military maneuvers and recreational traffic (pedestrians and off-road vehicles) increased fragmentation but did not lead to the reactivation of the dunes. Based on archival records and interviews with officials who have worked in the area over the past 25 years, it was concluded that the apparent changes in the stabilization process should be attributed to changes in the grazing and vegetation cutting practices of Bedouin farmers along the coast of Israel between the late 1960s and the late 1970s, concomitant with the changing policies of successive Israeli governments.