SEMIDE Système Euro-Méditerranéen d'Information sur les savoir-faire dans le Domaine de l'Eau

Water Context 2/12
Last update: 2008-01-04

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Israel Water Context

  1. Abstract – Introduction
  2. Geographic Background
  3. Water Consumption
  4. The Water Sources
  1. Rainfall
  2. Surface Water
  3. The Coastal Aquifer
  4. The Kinneret Basin
  1. The Mountain Aquifer
  2. Small Basins
  3. The Water Conveyance System
  4. Alternative Water Sources

2. Geographic Background

The Country

Israel is located in the southeastern basin of the Mediterranean Sea, between the Mediterranean Sea (in the west), Egypt (in the southwest), Jordan and Syria (in the east) and Lebanon (in the north). (click here to see map).

It comprises an area of 28,000 km2 (of which around 6000 km2 is in Judea and Samaria), extending over a long and narrow strip. Its length from north to south is around 430 km; its average width in the northern and central part ranges between -70 and -100 km and in its southern half it narrows down to its southernmost point, at Elat.

The country is divided into several geographic districts, from west to east: the coastal plain; the Shefela (foothills), the mountain strip; and the rift valley. The coastal plain is a low flat region, extending from the Mediterranean Sea coast eastward, over a strip that broadens towards the south from about 5 km in the north to about 20 km in the south. The climate in this area is moderate and moist because of its proximity to the sea. The region is built of calcareous sandstone (locally named kurkar) and sand of Pleistocene age, which constitute the coastal aquifer.

The Shefela foothills district, to the east of the coastal plain, is a region of moderate to hilly (up to a height of 300 m) topography. It is built of soft carbonate rocks and of a young alluvium cover in which there are broad agricultural areas. The Shefela is also wide in the south, narrowing greatly in the north of the country.

The mountain strip cuts across the entire length of Israel, from the Galilee in the north to the central Negev in the south. This mountainous district lies at an altitude of 700-00 m, with peaks at Mount Meron (1208+ m), Mount Ba'al Hazor (1016+ m) and Mount Ramon (1035+ m), and hence the temperatures in the region are also lower than in the rest of the districts. The strip of mountains is actually the heart of an anticline whose axis is oriented north-south. Exposed at the heart of the anticline are limestone and dolomite rocks of Cenomanian-Turonian age, which constitute an excellent aquifer. These rocks are covered by a thick layer of younger impermeable rocks (aquiclude) that are exposed on both sides of the anticline, though are particularly thick in the Shefela.

The Jordan Valley is a narrow valley that formed as a result of tectonic movements of geologic plates. The Jordan River flows in the valley, beginning at its sources, flowing from the slopes of Mount Hermon, through Lake Kinneret, at a -210 m altitude, down to the Dead Sea at -400 m below sea level (the lowest place on earth!). The climate in the rift valley is hotter and drier than in the other districts in the country. In the north, rising beyond the rift is Mount Hermon (the highest mountain in Israel, 2224+ m) and the basalt plateau in the Golan. In the center of the country, between the mountain strip and the rift, lies the Judea Desert in which hot and dry conditions prevail as it falls in the " rain shadow" – that is, the clouds arriving from the west rain down most of the water collected in them while rising to the mountain ridge, and after passing the water divide, dropping relatively little rain.

The climate in most of Israel is Mediterranean – a long, clear, hot and dry summer, a cloudy, cold and rainy winter (the rains) – which is dictated by the proximity of the country to the Mediterranean Sea. In the mountains in the north of the country precipitation is around 900 mm per year, in the centre, around 600 mm/yr, whereas in the south of the country it is less than 20 mm/yr. A 200 mm/yr isohyet (a line of equal rainfall) passing close to Beer Sheva, divides the country into two parts – the north, in which there is natural vegetation and non-irrigated crops, and the Judea Desert and the south that are dry, and is thus called the "desert boundary." The southern half of Israel is part of the world desert belt (latitude 20-40) and there, with its distancing from the Mediterranean Sea, the climate becomes arid and dry.

The natural manifestation of the climatic differences is the development of different phytogeographic provinces (vegetation provinces). Four phytogeographic provinces meet in Israel: the Mediterranean, the Irano-Turanian, the Saharo-Arabic, and the Sudanic. The Mediterranean province spreads across the northern part of Israel, to Ashqelon and to the southern Judea Mountains. Formerly, the area was covered with natural forests of oak, terebinth, and carob trees, etc., but today, the natural vegetation has almost disappeared. In its place many pine groves were planted and lower vegetation, such as spiny broom (Calicotome villosa), sage (Salvia), rockrose (Cistus), prickly burnet (Sarcopoterium spinosum), and more, has spread. The Irano-Turanian province includes the Hermon, the Jordan Valley, the Judea Desert and the north and central Negev. These regions are characterized by more extreme climatic conditions – by both a cold winter and a hot summer. The natural vegetation constitutes low bushes such as lotus jujube (Ziziphus lotus), white wormwood (Artemisia sieberi), and more. In the south of the country some large Atlantic terebinth trees, remnants of different climatic conditions in the historic past, have even been preserved. The Saharo-Arabic province includes the Judea Desert and the Negev that are characterized by a very short rainy season with comfortable temperatures and a very long, dry, hot season. The amounts of rain are not sufficient to sustain vegetation, except in the channels and in the depressions that drain the water. The Sudanic province includes a small part of the southern Arava, and it is characterized by plants that adapt to insignificant amounts of precipitation.

The Population

The population of Israel numbers around 6.9 million persons, around 6.3 million (92%) of them living in urban settlements. Around two-thirds of the population and most of the industrial plants and commercial centers are concentrated in the coastal plain, from Akko (Acre) in the north to Ashqelon in the south. Other cities are spread further inland, the largest among them: Jerusalem, Rehovot, Beer Sheva, Modi'in and Karmiel.

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