Topography and Morphology
p. 42-46
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1Jordan is a Middle Eastern country located between N. Latitudes 29° 11’ and 33° 22’ and E. Longitudes 34° 59’ and 39° 12’. It is bordered by Syria to the north, Iraq to the east, Saudi Arabia to the east and south, and Israel and the West Bank to the west. The Gulf of Aqaba, located in the southwest of Jordan, is the country’s only outlet to the Red Sea. Although Jordan is a small country (89,320 km²) and three-quarters of its territory is desert, the landscape reveals great diversity within short distances. Five main physiographic regions of Jordan extend in a north–south alignment and comprise: tropical desert in the central Ghor or rift valley, escarpments and mountain highlands east of the Ghor, arid plains, the Badiya and the Azraq and Wadi Sirhan depression. These five physiographic regions correspond to five major morphological zones (Bender 1974).
The Jordan Valley and the Wadi Araba Rift (Ghor)
2The Jordan Depression running from Wadi Araba to the Dead Sea is a very distinctive landscape; it forms part of the Rift Valley that extends from North Syria down to East Africa. This linear feature runs north-south with significantly lower elevations than the Highlands to the east, and extends about 360 km from Lake Tiberias to the Gulf of Aqaba. The Depression gradually rises from the Gulf of Aqaba over a distance of about 80 km up to about 250 m above sea level, and then drops gently towards the Dead Sea (419 m below sea level), the depression then rises in elevation from 419 m below sea level to 210 m below sea level at Lake Tiberias. Most of the depression is on average 15 km wide.
3This region is the lowest depression on earth (with the Dead Sea at 419 metres below sea level) and includes the Jordan River, flowing through the Jordan Valley, which is considered the food basket of Jordan. The Jordan Valley (with its dams) and the Southern Ghor (with its surface water) are among the most important agricultural areas, since there is a permanent supply of water from the Yarmouk River. Due to high temperatures and their location below sea level, these two regions are the most important areas for producing winter vegetables. The Ghor has approximately 34,000 hectares of farming land, all of which is irrigated (fig. I.2).
Figure I.2 — Jordan Five Main Morphological Units.
Highlands at the Eastern Edge of the Wadi Araba-Jordan Graben
4This zone, referred to both as the Mountain Ridge and the Northern Highlands, east of the rift and the Transjordanian Plateau, slopes gently towards the central plateau in the east, and drops steeply towards the Dead Sea Rift in the west. Tectonic activity and structural movements within and in the vicinity of the Graben have until recent geological times continually lowered the base level of the wadis and perennial rivers draining to the west. The relatively high surface runoff has caused excessive active erosion (fig. I.3).
5The northern Highlands extend from Umm Qays in the north through the Ajlun Mountains, the hills of Amman and Moab, and the Edom Mountains. This region is intersected at several points by deep wadis such as the Wadi Mujib and Wadi Yabes, which are shaped like canyons. The southern Highlands are higher than those in the north, but with less variety and density of vegetation. Of special interest are the Wadi Rum and Rum Mountain, the highest mountain in Jordan (with Jabal Umm al Dami at 1,854 m.) and Um Eshrin Mountain at 1,753 m.
6The highlands are home to the Kingdom’s natural forests, which make up less than one percent of the total surface area.
Figure I.3 — Jordan Four Main Physiographic Regions.
Central Desert Areas of East Jordan (Arid Plains)
7This zone includes the plains between the Badiya (semi-desert) and the Highlands. Rainfall ranges between 200 mm in the east and 350 mm in the west. More than 50 percent of arable land is located in this zone. The rain-fed crops are mainly barley (200-300 mm of rainfall), wheat and fruit trees (300-350 mm of rainfall).
8The landscape here is distinctive; it is practically flat or gently sloping, and is generally covered in sharp-edged chert rock. Chert debris covers hundreds of squares kilometres and the area is known as the flint-strewn desert (in Arabic: Hammad land or Hammada). In the south it rises to about 850 m towards the Depression of al-Jafr which is a flat, oval, dish-like depression. The centre of al-Jafr Depression is partly mud flats, in Arabic: Qa‘.
9This zone ends southwest of al-Jafr Depression at the escarpment of Ras al-Naqb, with altitudes reaching 1,700 m in some areas. Near Ras al-Naqb, the difference in altitude from base to top of the escarpment is about 600 m.
The Badiya Region (North-Eastern Desert)
10This extensive region covers about 8,090,000 hectares or 90% of the Kingdom. It meets the Arabian Desert at the borders of three Arab countries: Syria to the north, Iraq to the east and Saudi Arabia to the south. It is a plateau with an elevation of 600 to 900 metres, extending eastwards. This part of the Syrian Badiya covers most of Jordan and has diverse characteristics. Most of the Badiya region is divided into two broad areas, namely, the Northeast Jordanian Basalt Plateau, and the Northeast Jordanian Limestone Plateau, which is located east northeast of the country.
11The Northeast Jordanian Basalt Plateau, frequently referred to in Arabic as Harrat al-Shaba, meaning Black Desert, covers an area of about 11,000 km² in Jordan. This Plateau has many isolated hills and long rows of volcanoes. Elevation ranges from between 500 m to 550 m, and reaches more than 1,100 m in the NNW at the northern border of Jordan.
12The Northeast Jordanian Limestone Plateau is monotonous, flat, stony desert that extends eastward from the Black Desert beyond the eastern borders of Jordan. The land rises in all directions from the eastern margin of the Basalt Plateau, with elevations between 625 m and 800 m. This Limestone Plateau forms a flat, dish-like depression.
13Very sparse vegetation and an annual rainfall of less than 200 mm characterize the Badiya region. In the past it was only used for grazing, but in the last two decades 20,000 ha. have been irrigated using underground water to grow vegetables (especially tomatoes, watermelon and potatoes), fruit trees and cereals, especially wheat. The Badiya contains two main depressions: Azraq and Jafr.
Azraq-Wadi Sirhan Depression
14This is a well-defined morphological area. The axis of the depression gradually rises from 500 m to 700 m in the southeast. This depression collects water from adjacent wadis and was of great importance for nomads in the past. It was an important trade route between the Highlands and the Arabian Peninsula.
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