Agrarentwicklung und Landdegradation im Nahen Osten seit dem Neolithikum am Beispiel Israels

The Mediterranean-type climate region is an inherently unstable earth-surface system. Human impact is a major factor in land degradation in the Mediterranean region. It starts with the appearance of Man in Israel about 1.5 million years ago, but the major effects on landscape modification occurred in historic times. Seven phases of land degradation are recognized, since the first one covering the Paleolithic period until the present one, covering the last three decades, when the degradation processes aggravated. Land degradation processes like wild fires and urbanization, increases the seasonality of flow stream, with higher runoff rates in the winter floods and less percolation into groundwater, decreasing springs discharge and lowering exploitable aquifers. The increased variability causes more flood damage and erosion, making water management a more complex and expensive task. Water recycling for irrigation increased soil salinization, as salt flushing by the natural river system was impeded. Forest fires have increased, and on average 5% of the forests in Israel are burnt each year. Urbanization changes the surface to an impervious one, increasing the runoff/rainfall ratio from 1-2% under natural conditions to more than 50%. The coastal area of Israel is a narrow and fragile strip, with an enormous human pressure for intense exploitation. Human interference in the Mediterranean environment exacerbates the negative natural biophysical processes, and the results are more frequent and more severe geomorphic events, as floods, landslides and soil erosion.