Land Degradation in the Sultanate of Oman: Reasons and Intervention Measures - Combating Desertification in Asia, Africa and the Middle East - page 388

1.3 Physiographic Regions

The Sultanate consists of Plains, Wadis and Mountains. The most important area
is the plain overlooking the Gulf of Oman and the Arabian Sea with an Area of
9,000 km 2 (3 % of the total) while Mountains Ranges occupy about 45,000 km 2
(15 %). The remaining area is simply sand and desert which includes part of
Ar-rub Al-Khali (empty quarter) occupying 246,000 km 2 (82%)ofthetotalareas.
According to the general soil map of Oman (MAF 1990) Oman is divided into
eleven Physiographic regions:

1.3.1 Arid Mountains

These are encountered mostly in the Hajar Mountains, in northern Oman, including
the Musandam peninsula. They also occur to a much smaller extent in islands
such as Masirah and Al-Halanyatt These Mountains are mostly steep and barren
formations of igneous and sedimentary rocks.
The Hajar mountains range stretches northwest southeast, along the Gulf of
Oman, over about 700 km from Ras-Al-Hadd to Musandam. Its width varies
between about 30-70 km.
Bare rock outcrop and very shallow soils are dominant on sloping terrain,
whereas very gravelly soils occur in valleys and alluvial fans. With summits nearing
3,000 m above sea level in Jabal Lakhdar, the Hajar mountains intercept moist air
masses, hence receiving relatively higher precipitation than surrounding areas. A
dense network of wadis conveys drainage water north to the Batinah plain, and south
to the interior of Oman.
A large number of scattered oases, mostly using falaj irrigation systems, tap local
springs or wadis underflow, to grow mostly date palm, limes, alfalfa and vegetables.

1.3.2 Monsoon-Affected Mountains and Plateaus

This kind of landscape occurs only in two separate areas, both in the Dhofar region.
One is north of Salalah, the other, along Rakhyut coast.
These areas are strongly dissected. A woody vegetation predominates on steep
slopes and gullies, whereas grass and bushes, under heavy grazing, cover most of
the relatively flat areas.
Soils are generally shallow in the grazed areas, suggesting that soil erosion is
very active in the rangelands. Wooded slopes, protected from erosion by trees and
bushes, generally have moderately deep soils.
Rainfed cultivation of beans and sorghum is done by some Jabali in very tiny
plots during the monsoon.