PHYSICAL PATTERNS

Landforms and climates are particularly closely related in this region. The climate is dry and hot in the vast stretches of the relatively low, flat land; it is somewhat moister where mountains capture orographic rainfall. The lack of vegetation perpetuates aridity. Without plants to absorb and hold moisture, the rare but occasionally copious rainfall simply runs off, evaporates, or sinks rapidly into underground aquifers, of which there are many across the region.

No other region in the world is as dry as North Africa and Southwest Asia (Figure 6.5A). A belt of dry air that circles the planet between roughly 20° N and 30° N creates desert climates in the Sahara of North Africa, the eastern Mediterranean, the Arabian Peninsula, Kuwait, Iraq, and Iran.

The Sahara’s size and location under this high-pressure belt of dry air make it a particularly hot desert region. In some places, temperatures can reach 130°F (54°C) in the shade at midday (see Figure 6.1A). With little water or moisture-holding vegetation to retain heat, nighttime temperatures can drop quickly to below freezing. Nevertheless, in even the driest zones, humans survive as traders and nomadic herders at scattered oases, where they maintain groves of drought-resistant plants such as date palms. Desert inhabitants often wear light-colored, loose, flowing robes that reflect the sunlight, retain body moisture during the day, and provide warmth at night.

In the uplands and at the desert margins, enough rain falls to nurture grass, some trees, and limited agriculture. Such is the case in northwestern Morocco; along the Mediterranean coast in Algeria, Tunisia, and Libya; in the highlands of Sudan, Yemen, and Turkey; and in the northern parts of Iraq and Iran (see Figure 6.5B–D). The rest of the region, generally too dry for cultivation, has for generations been the prime herding lands for nomads, such as the Kurds of Southwest Asia, the Berbers and Tuareg (a branch of Berbers) in North Africa, and the Bedouin of the steppes and deserts on the Arabian Peninsula. Recently, most nomads have been required to settle down; some of their lands are now irrigated for commercial agriculture, but the general aridity of the region means that sources of irrigation water (rivers and aquifers) are scarce.

The rolling landscapes of rocky and gravelly deserts and steppes cover most of North Africa and Southwest Asia (see the Figure 6.1 map and Figure 6.5). In a few places, mountains capture sufficient moisture to allow plants, animals, and humans to flourish. In northwestern Africa, the Atlas Mountains, which stretch from Morocco on the Atlantic coast to Tunisia on the Mediterranean coast, lift damp winds from the Atlantic Ocean, creating orographic rainfall of more than 50 inches (127 centimeters) per year on windward slopes (see Figure 6.1B). In some Atlas Mountain locations, there is enough snowfall to support a ski industry.

A rift that formed between two tectonic plates—the African Plate and the Arabian Plate—separates Africa from Southwest Asia (see Figure 1.8). The rift, which began to form about 12 million years ago, is now filled by the Red Sea. The Arabian Peninsula lies to the east of this rift. Mountains bordering the rift in the southwestern corner rise to 12,000 feet (3658 meters). They capture enough rainfall to sustain agriculture, which has been practiced there for thousands of years. Irrigation has been used for millennia to increase yields.

Behind these mountains, to the northeast of the Arabian Peninsula, lies the great desert region of the Rub‘al Khali. Like the Sahara, it has virtually no vegetation. The sand dunes of the Rub‘al Khali, which are constantly moved by strong winds, are among the world’s largest, some as high as 2000 feet (610 meters; see Figure 6.1D).

The landforms of Southwest Asia are more complex than those of North Africa. The Arabian Plate is colliding with the Eurasian Plate and pushing up the mountains and plateaus of Turkey and Iran (see Figure 1.8). Turkey’s mountains lift damp air that passes over Europe and the Mediterranean from the Atlantic, resulting in considerable rainfall (see Figure 6.1E). Only a little rain makes it over the mountains to the interior of Iran, which is very dry. The tectonic movements that create mountains also create earthquakes, a common hazard in Southwest Asia.

There are only three major river systems in the entire region, and all have attracted human settlement for thousands of years. The Nile flows north from the moist central East African highlands (see Figure 6.1F). It crosses arid Sudan and desert Egypt and forms a large delta on the Mediterranean. The Euphrates and Tigris rivers both begin with the rain that falls in the mountains of Turkey. The rivers then flow southeast to the Persian Gulf. A much smaller river, the Jordan, starts as snowmelt in the uplands of southern Lebanon and flows through the Sea of Galilee to the Dead Sea. Most other streams are for most of the year dry riverbeds, or wadis, carrying water only after the generally light rains that fall between November and April (Figure 6.1G shows a wadi in Morocco).

North Africa and Southwest Asia were home to some of the very earliest agricultural societies. Today, rain-fed agriculture is practiced primarily in the highlands and along parts of the Mediterranean coast, where there is enough precipitation to grow citrus fruits, grapes, olives, and many vegetables, though supplemental irrigation is often needed. While irrigated agriculture is an age-old type of farming, it has become increasingly significant in modern times, both in the valleys of the major rivers, where seasonal flooding fills irrigation channels, and where aquifers are tapped by wells to provide water for cotton, wheat, barley, vegetables, and fruit trees.

Environmental concerns are only beginning to be an overt focus in this region. This is in part because for thousands of years people here have confronted the challenges of a naturally arid environment and have been quite attuned to its scarcities, which exceed those in most other places on Earth (Figure 6.6).

The Qur’an (or Koran), the holy book of Islam, guides believers to avoid spoiling or degrading human and natural environments and to share resources, especially water, with all forms of life. In actual practice, the residents of this region conserve water better than most people in the world. Daily bathing is a religious requirement and is often done in public baths, where water use is minimized. For millennia, mountain snowmelt has been captured and moved to dry fields and villages via constructed underground water conduits, called qanats, that minimize evaporation. Likewise, traditional architectural designs that maximize shade and airflow are used to create buildings that stay cool.

Despite their history of water-conserving technologies and practices, however, this region’s 477 million residents now have such limited water resources that even clever combinations of ancient and modern measures are no longer sufficient to ensure an adequate supply of water. Growing populations, water pollution, and unwise modern usages of water virtually guarantee that water shortages will be more extreme in the future (Figure 6.7A–C), especially with the likelihood of climate change–related drier conditions. As shown in the map in Figure 6.6, Turkey has the most plentiful water resources, followed by Iran, Iraq, and Syria. However, all other countries in the region suffer from freshwater scarcity, meaning that they have less water than the minimum the United Nations considers necessary to support basic human development—1000 cubic meters per person per year.

A recent reassessment of groundwater storage in North Africa by a consortium of British scientists revealed that deep aquifers in Algeria, Libya, Egypt, and Sudan may hold up to 100 times the water available through renewable freshwater resources (Figure 6.8). This fossil water, deposited thousands of years ago, is unevenly distributed and so deep that special pumps are required to bring it to the surface. There probably isn’t enough to meet the expected increases in demand for agricultural irrigation and drinking water for rapidly growing urban populations, but this stored groundwater may help alleviate scarcities caused by climate variability.

The predominant use of water in North Africa and Southwest Asia is for irrigated agriculture, even though agriculture does not contribute significantly to national economies. In Tunisia, for example, agriculture accounts for just 10 percent of GDP but 86 percent of all the water used. Just 13 percent of water is used in homes, and only 1 percent by industry. Most national governments actually subsidize irrigated agriculture because they are worried about depending completely on imported food. Irrigated agriculture also supports jobs and family economies that are crucial to rural communities. Some of this region’s food specialties appear in Figure 6.9.

Until the twentieth century, agriculture was confined to a few coastal and upland zones where rain could support cultivation, and to river valleys (such as the Nile, Tigris, and Euphrates valleys) where farms could be irrigated with simple gravity-flow technology. However, to accommodate population growth and development, Libya, Egypt, Saudi Arabia, Tunisia, Syria, Turkey, Israel, and Iraq all now have ambitious mechanized irrigation schemes that have expanded agriculture deep into formerly uncultivable desert environments (see Figure 6.7B, C).

Over time, irrigation projects damage soil fertility through salinization. When irrigation is used in hot, dry environments, the water evaporates, leaving behind a salty residue of minerals. When too much residue accumulates, the plants are unable to grow or even survive. This human-induced loss of fertility is one of the largest environmental water issues that the world faces today in arid and semiarid regions.

Israel has developed relatively efficient techniques of drip irrigation that dramatically reduce the amount of water used, thereby limiting salinization and freeing up water for other uses. Until very recently, however, poorer states have been unable to afford this somewhat complex technology, which requires an extensive network of hoses and pipes to deliver water to each plant.

North Africa and Southwest Asia are especially vulnerable to the multiple effects of climate change. Higher temperatures are already increasing evaporation rates where water scarcity has been a problem for many years (Figure 6.10B, C). These climatic changes, along with people’s intensified use of water, are transforming more nondesert lands into deserts. Also, as the climate warms, a sea level rise of a few feet could severely impact the Mediterranean coast, especially the Nile Delta, one of the poorest and most densely populated lowland areas in the world (see Figure 6.10A), and the Persian Gulf coasts, where vast new high-tech cities that lie at sea level would likely be flooded (see Figure 6.24A). Conversely, under some climate-change scenarios, periods of unusually intense rainfall could increase flooding.

Independent of any environmental effects of climate change, global efforts to reduce dependencies on fossil fuel consumption could devastate oil- and gas-based economies and transform the region’s geopolitics, leaving countries vulnerable to losing some of their global power and to having lower overall income levels. Despite the enormous wealth from fossil fuel sales that has flowed into some of these countries over the past 40 years, few countries have undertaken the significant economic diversification needed to prepare for the reduced global consumption of the fossil fuels they sell.

Climate Change and Desertification Climate change could accelerate desertification, the conversion of nondesert lands into deserts (see Figure 6.7A). As temperatures increase, soil moisture decreases because of evaporation. As a result, plant cover is reduced, which causes less protection for arid soil. Bare patches of soil can become badly eroded by wind, and eventually sand dunes can blow onto formerly vegetated land.

In the grasslands (steppes) that often border deserts, a wide array of land use changes contribute to the general drying. For example, as groundwater levels fall because water is being pumped out for cities and irrigated agriculture, some plant roots no longer reach sources of moisture, causing the plants to die. In other cases, international development agencies have inadvertently contributed to desertification by encouraging nomadic herders to take up settled cattle ranching of the type practiced in western North America. Agencies encourage settlement because the mobility of nomads is viewed as complicating management for modern state bureaucracies where records must be kept, taxes collected, and children sent to school with regularity. However, ranching on fragile grasslands can lead to overgrazing, which can kill the grasses and increase evaporation. If irrigation is used to support ranching, such projects can also deplete groundwater resources, resulting in long-term desertification. Incidentally, encouraging nomads to settle may actually increase their vulnerability to climate change, because it is their very mobility and skills at cycling seasonally through multiple environments that have helped nomads adapt to climate variability over many generations.

Imported Food and Virtual Water Because agriculture is so difficult due to the aridity of this region, the diets of nearly all people here include imported food. The total per capita water use of this region must thus include the water used to produce this imported food. Virtual water is the volume of water used to produce all that a person consumes in a year (see Chapter 1). For example, 1 kilogram (2.2 pounds) of beef requires 15,500 liters (4094 gallons) of water to produce, while 13 kilogram of goat meat requires just 4000 liters (1056 gallons). Goat meat, which is popular in this region and produced locally, has a much less significant water component than beef, but beef consumption is on the rise. One kilogram of corn requires 900 liters (238 gallons) of water, and 1 kilogram of wheat, 1350 liters (357 gallons). Beef, corn, and wheat are common imports; in fact, North Africa and Southwest Asia import more wheat than any other world region.

Strategies for Increasing Access to Water Some strategies have been developed for increasing supplies of fresh water, but each presents a set of difficulties. All of them are expensive and some have enormous potential to cause more wasting of water.

Seawater desalination The fossil fuel–rich countries of the Persian Gulf have invested heavily in seawater desalination technologies that remove the salt from seawater, making it suitable for drinking or irrigation. Subsidized desalination plants supply 70 percent of Saudi Arabia’s drinking water and some of its wheat field irrigation. The process of desalination uses huge amounts of energy, which is produced by burning fossil fuels and results in emissions that contribute to global warming. If all the costs of producing food with desalinated water were counted—the fuel burned, the cost of irrigation and other equipment, and the fact that irrigated soil inevitably loses productivity due to soil salinization—the wheat so produced would be far too expensive for anyone to buy. Government subsidies for desalination have kept the wheat artificially cheap, though there are now plans to remove these subsidies so that the water can be used by urban populations.

Groundwater pumping Many countries pump groundwater from underground aquifers to the surface for irrigation or drinking water. Under Muammar el-Qaddafi, Libya had invested some of its earnings from fossil fuels into one of the world’s largest groundwater pumping projects, known as the Great Man-Made River. This project draws on part of the ancient fossil water deposit mentioned earlier to supply almost 2 billion gallons of water per day to Libya’s coastal cities and to 600 square miles of agricultural fields. With this irrigated agriculture, Libya had hoped to grow enough food to end its current food imports and even supply food to the European Union. However, the rate of natural replenishment of the aquifer is far slower than the rate of extraction, making this use of groundwater unsustainable. Hydrologists report fissures in the land surface above the aquifer that they associate with land sinking, or subsidence, as the water is withdrawn.

Dams and reservoirs Dams and reservoirs built on the regions’ major river systems to increase water supplies have created new problems. In Egypt, for example, the natural cycles of the Nile River have been altered by the construction of the Aswan dams. Downstream of these two dams, water flows have been radically reduced, making it necessary to use supplemental irrigation, which leads to soil salinization (see Figure 6.7C), and the lack of flooding means that fertility-enhancing silt is no longer deposited on the land. As a result, expensive fertilizers are now necessary. Moreover, with less water and silt coming downstream, parts of the Nile Delta are sinking into the sea or are experiencing saltwater intrusion because the seawater is flowing into aquifers and wells in coastal zones, rendering once-fresh water unusable. Upstream, the artificial reservoir created by the dams has flooded villages, fields, wildlife habitats, and historic sites, and created still-water pools that harbor parasites. Dams can also cause hardship across borders. The Aswan High Dam sits on Egypt’s border with Sudan, an area that has been a source of contention for many years.

Dams as water-acquisition strategies strain cross-border relations The need to share the water of rivers that flow across or close to national boundaries often impedes national development efforts. Turkey’s Southeastern Anatolia Project, which involves the construction of several large dams on the upper reaches of the Euphrates River for hydropower and irrigation purposes, has reduced the flow of water to the downstream countries of Syria and Iraq (Figure 6.11). In negotiations over who should get Euphrates water, for example, Turkey argues that it should be allowed to keep more water behind its dams because the river starts in Turkey and most of its water originates there as mountain rainfall. Meanwhile, Iraq’s claim to the water is linked to the fact that the Euphrates travels the longest distance in Iraq. 285. THE JORDAN RIVER IS DYING