Rangelands occupy about half the area in West Asia. They have low carrying capacity.

1.1.2.2 Water resources

While CWANA covers 15% of the world area, it has only 2% of internal renewable water resources (WRI et al., 1998), making it the world's most water-stressed region. Water availability by CWANA subregion in the year 2000 was classified as follows: North Africa catastrophically low, Nile Valley and the Red Sea very low, Arabian Peninsula catastrophically low, West Asia very low, Central Asia and the Caucasus low. In the Arabian Peninsula, the water-stress index is 100%. The subregion has hyperarid and arid climates with an annual rainfall less than 100 mm.

The total available water is about 15 billion m³ annually. Surface water comprises about 45%, groundwater about 41%, desalinization about 12% and agricultural drainage reuse about 2%. Agriculture uses about 86% of the available water in CWANA. Excessive use of groundwater has resulted in sharp decline in its amount and quality because seawater is intruding (UNEP, 2002b).

West Asia has a water stress index of 83%. The subregion is mostly arid and semiarid. Most countries in the subregion receive less than 250 mm of rain per year. Two major rivers, the Euphrates and Tigris, are shared by Iraq, Syria and Turkey. Total available water resources are about 80 billion m³ each year, 85% surface water, 10% groundwater and 5% agricultural drainage reuse. Agriculture uses about 80% of the available water. Effluent, agrochemicals and industrial discharges have seriously affected water quality. CWANA's driest country is Mauritania, where the average annual renewable water resources are less than 0.5 billion m³. Water resources are poorly managed and inefficient across CWANA. In some areas farmers over-irrigate wheat crops 20 to 60%.

Water scarcity must be dealt with before any development can be sustained. Any development in CWANA must recognize that vegetation and soils are sensitive to intensive use. Once degraded, many decades are needed to restore the production and hydrologic function of these ecosystems. Low and erratic precipitation prevents the rapid reestablishment of vegetation, leaving a degraded landscape exposed to water and wind erosion for a long time.

1.1.2.3 Status of soils

Data from the Global Assessment of Human Induced Soil Degradation (GLASOD) (UNEP/ISRIC, 1990) show that soil degradation is widespread in the whole CWANA region.

In North Africa, 70% of the degraded soils are through wind erosion, 20% water erosion and 10% through nutrient depletion and soil salinization. Soil erosion is a widespread problem in North Africa, with severity highest at the western and eastern ends of the Atlas and Rif mountains. In the lower parts, centuries-old, traditional soil conservation techniques are breaking down. The Nile Valley of Egypt has substantial chemical degradation problems, involving both salinization and nutrient depletion. In many of the upland areas of the Nile Valley and the Red Sea, land degradation has reached critical levels (UNEP, 1997). About 64 million ha of soils are degraded to varying degrees in Sudan. Wind erosion is the dominant cause of soil degradation in the arid zone, while water erosion is dominant in the semiarid zone.

Nutrient loss affects all climatic zones of Sudan (Ayoub, 1998). Most of Somalia is affected by wind erosion, with a small area in the southern part affected by water erosion. In Yemen, 50% of the soils are affected by water erosion and 20% by wind erosion. High to very high severity of nutrient depletion is taking place in the sandy soils of Sudan, the Arabian Peninsula and Central Asia. The dominant cause of soil degradation is wind erosion in the Arabian Peninsula and West Asia, covering almost 60% of the degraded area, followed by soil salinization, 30%, and water erosion, mostly in Syria and Lebanon.

Inefficient use of irrigation water has resulted in salinization, alkalization and waterlogging. More than 50% of the irrigated lands in the Euphrates plains and in Pakistan have been badly affected by salinization and waterlogging (UNESCWA, 1997). Indeed, Pakistan is among the top five countries in the world with irrigated land damaged by salinization. About 300 million ha in CWANA are affected by soil salinity and alkalinity, nearly 30% of the world's saline and alkaline soils (Abrol et al., 1988). They occur in coastal areas and inland salt marshes. Soil salinity is severe in the Euphrates and Tigris valleys of Syria and Iraq. The southern part of Pakistan is affected by wind erosion and soil salinity, while the northern part is affected by water erosion. Afghanistan is mostly affected by water erosion, while the southwestern part is affected by wind erosion and soil salinity. The bulk of Iran is affected by wind erosion. Its northern and western parts are affected mainly by water erosion. Soil salinity is also widespread and most severe in areas bordering Iraq and Afghanistan. The total area of saltaffected soils in Iran is about 15% (Koocheki and Mohalati, 1992). Turkey is seriously affected by water erosion; a few areas have water erosion coupled with nutrient depletion and soil salinity.

The Caucasus is two-thirds desert, the Usturit and Kyzilkum deserts. Soils are commonly salinized. The lowlands are salt accumulation zones and saline soils dominate (Zhang et al., 1992). Turkmenistan lies within these deserts. There are two large seas, the Caspian and the Aral. The Aral Sea is dying because its input water is diverted for agriculture. It shows the most recent example of human-induced environmental degradation in the subregion (UNEP, 1997). Fortunately, a big portion of Tajikistan is stable under natural conditions. Azerbaijan has various degrees of water erosion and extensive soils affected by salinity. The whole of Kyrgyzstan suffers various degrees of water erosion, wind erosion and soil salinization.