Jordan Table of Contents
Figure 4. Topography and Drainage
The country consists mainly of a plateau between 700 and 1,000 meters high, divided into ridges by valleys and gorges, and a few mountainous areas. Fractures of the earth's surface are evident in the great geological rift that extends southward from the Jordan Valley through the Gulf of Aqaba and the Red Sea, gradually disappearing south of the lake country of East Africa. Although an earthquake-prone region, as of early 1989 no severe shocks had been recorded for several centuries.
By far the greatest part of the East Bank is desert, displaying the land forms and other features associated with great aridity. Most of this land is part of the great Syrian (or North Arabian) Desert (see fig. 4). There are broad expanses of sand and dunes, particularly in the south and southeast, together with salt flats. Occasional jumbles of sandstone hills or low mountains support only meager and stunted vegetation that thrives for a short period after the scanty winter rains. These areas support little life and are the least populated regions of Jordan.
The drainage network is coarse and incised. In many areas the relief provides no eventual outlet to the sea, so that sedimentary deposits accumulate in basins where moisture evaporates or is absorbed in the ground. Toward the depression in the western part of the East Bank, the desert rises gradually into the Jordanian Highlands--a steppe country of high, deeply cut limestone plateaus with an average elevation of about 900 meters. Occasional summits in this region reach 1,200 meters in the northern part and exceed 1,700 meters in the southern part; the highest peak is Jabal Ramm at 1,754 meters. These highlands are an area of long-settled villages. Until about the 1940s, persons living in these villages depended upon rain-fed agriculture for their livelihood.
The western edge of this plateau country forms an escarpment along the eastern side of the Jordan River-Dead Sea depression and its continuation south of the Dead Sea. Most of the wadis that provide drainage from the plateau country into the depression carry water only during the short season of winter rains. Sharply incised with deep, canyonlike walls, whether wet or dry the wadis can be formidable obstacles to travel.
The Jordan River is short, but from its mountain headwaters (approximately 160 kilometers north of the river's mouth at the Dead Sea) the riverbed drops from an elevation of about 3,000 meters above sea level to more than 400 meters below sea level. Before reaching Jordanian territory the river forms Lake Tiberias, the surface of which is 212 meters below sea level. The Jordan River's principal tributary is the Yarmuk River. Near the junction of the two rivers, the Yarmuk forms the boundary between Israel on the northwest, Syria on the northeast, and Jordan on the south. The Az Zarqa River, the second main tributary of the Jordan River, rises and empties entirely within the East Bank.
A 380-kilometer-long rift valley runs from the Yarmuk River in the north to Al Aqabah in the south. The northern part, from the Yarmuk River to the Dead Sea, is commonly known as the Jordan Valley. It is divided into eastern and western parts by the Jordan River. Bordered by a steep escarpment on both the eastern and the western side, the valley reaches a maximum width of twenty-two kilometers at some points. The valley is properly known as the Al Ghawr (the depression, or valley, also seen as Al Ghor; see Water , ch. 3).
The rift valley on the southern side of the Dead Sea is known as the Southern Ghawr and the Wadi al Jayb (popularly known as the Wadi al Arabah). The Southern Ghawr runs from Wadi al Hammah, on the south side of the Dead Sea, to Ghawr Faya, about twenty-five kilometers south of the Dead Sea. Wadi al Jayb is 180 kilometers long, from the southern shore of the Dead Sea to Al Aqabah in the south. The valley floor varies in level. In the south, it reaches its lowest level at the Dead Sea (more than 400 meters below sea level), rising in the north to just above sea level. Evaporation from the sea is extreme due to year-round high temperatures. The water contains about 250 grams of dissolved salts per liter at the surface and reaches the saturation point at 110 meters.
The Dead Sea occupies the deepest depression on the land surface of the earth. The depth of the depression is accentuated by the surrounding mountains and highlands that rise to elevations of 800 to 1,200 meters above sea level. The sea's greatest depth is about 430 meters, and it thus reaches a point more than 825 meters below sea level. A drop in the level of the sea has caused the former Lisan Peninsula to become a land bridge dividing the sea into separate northern and southern basins.
Data as of December 1989
Jordan Table of Contents