Khalil Khani, Ph.D.*
Two major environmental hazards affecting the planet earth in the developing world including Iran in terms of nature and magnitude are the problems of deforestation and desertification. Overgrazing, fire, and deforestation thin out or destroy vegetation, leaving exposed soil prone to wind, and water erosion or flooding. Once the nutrient rich top soil blows or washes away, plants may not be able to revive.
Overgrazing causes soil compactation, destruction, and elimination of vegetation cover and changes the soil texture. So, rain no longer penetrates the soil, and the plants will lose the water they need to grow.
The livestock population is around three times higher today than the capacity of the rangelands in Iran. The consequence of such conditions results in devastating floods, loss of lives, economic damages, and destruction of people’s livelihood. Once, the destructive forces are lifted, sheep or cattle are removed, and the vegetation community is not recovered, so, the land becomes desertified. The loss of productive land for a season or even a few years is one thing, but to lose it effectively forever is clearly far more serious. Later is the case in Iran, where some destruction had become irreversible.
Desertification is defined as “land degradation in arid, semiarid and dry sub-humid areas resulting from climate change and human activities”. Land degradation is emerging as one of the most globally catastrophic issues in the context of contemporary climate change and non-controlled anthropogenic activities. Several natural hazards take place in the arid and semi-arid regions: periodic droughts, floods, dust storms, and sand storms that are aggravated by human activities. Yet, there is no clear consensus among scientists regarding how to combat desertification and land degradation, and the main factors driving these phenomena continue to be debated. Desertification is also considered as the reduction or total loss of land productivity imposed by a combination of soil erosion, degradation of soil properties, and long-term loss of natural vegetation. During the last century, approximately 70% of drylands have manifested signs of desertification, among different degraded land use categories, croplands had experienced the highest risk.
Iran represents one of the clearest examples of a country deeply affected by land degradation processes such as soil erosion, reduction of soil productivity, and water quantity as well as its quality. However, the lack of data noted by several Iranian investigations means that comprehensive nationwide studies that consider recent climate and vegetation trends are scant.
Drylands of Iran are susceptible to degradation and desertification due to various natural and human activities. At the heart of these activities are plundering of Iran’s natural ecosystems, unusual numbers of IRGC’s dams construction, depleting aquifers, and diverting water resources for the lands owned by various religious foundations or affluent clerics and other privileged individuals of authority. Numerous examples illustrate the effects of long term and over time, vegetation loss including an increase in flash floods associated with loss of fertile topsoils. Land degradation poses a serious threat to the sustainable development of growing economies and will certainly undermine their political stability. All of such crises are associated with continuous neglect and mismanagement of the various governments under the rule of clerics in Iran.
Driving forces in the human environment such as population growth and the resulting increased demand for food had created environmental stresses, which is caused by overgrazing, misuse of agricultural land, improper irrigation techniques, over pumping of ground water, in excess of capacity for recharge, irregular transformation of rangelands to rain fed farming, continuous use of machinery, soil compaction, overexploitation of firewood, and hazardous pulling up of plants with medical interest. All these activities cause a reduction of the content of organic matter and of soil biodiversity. They cause the destruction of the soil structure and they reduce soil fertility and ultimately increase soil erosion.
Iran not only is becoming more vulnerable to desertification but also according to the Forests, Range and Watershed Management Organization, 100 million hectares of the country’s land area is threatened by desertification. This organization’s deputy has explained that currently 32.5 million hectares of land in the country are decertified.
More than 20 million hectares of land in 22 provinces, namely Sistan-Baluchestan, Semnan, Kerman, Isfahan, Markazi, Khuzestan, Khorasan Razavi, South and North Khorasan are regretfully prone to wind erosion.
The area of deserts in Iran is about 340,000 Km2 (less than one-fifth of its total area), of which 100,000 Km2 is being used for some cultivation, 120,000 Km2 is subjected to moving sands about 40% of which is active sand dunes. Most features and processes usual in world famous deserts are also observed in Iran: low precipitation, high evaporation, poor or lack of vegetation, saline and alkaline soils, low population and small and sparse oases.
The area of deserts in Iran is about 340,000 Km2 (less than one-fifth of its total area), of which 100,000 Km2 is being used for some cultivation, 120,000 Km2 is subjected to moving sands about 40% of which is active sand dunes. Most features and processes usual in world famous deserts are also observed in Iran: low precipitation, high evaporation, poor or lack of vegetation, saline and alkaline soils, low population and small and sparse oases.
Salinization is an important stress factor causing soil degradation and is the result of the accumulation of salts in the soil. Most salt affected soils developed through natural processes and a great number of them have existed for a long time. Human activities, which interfered with natural processes, created the extension of salt affected soils.
Salinity of soil and water resources is a serious threat and one of the most important ecological issues in many parts of Iran; slightly and moderately salt affected soils are mostly found in the northern part, whereas soils with high salinity levels are prevalent in the central and south part.
Altogether, two groups of deserts have been known in Iran. Coastal deserts stretch like a ribbon with variable width, from extreme southeast to extreme southwest, at the North parts of Oman Sea and Persian Gulf. One important feature of these deserts is relatively high humidity which differentiates them from other deserts. However, portions of this area exist in extremely fertile farmlands. The environmental conditions in this region of the country causes an increase in vegetation coverage and hence a decrease in eolian erosion and also a dominance of chemical weathering instead of physical.
Internal deserts rest in the central, eastern and southeastern plateau of the country as depressions. This situation is due to the surrounding high mountains, which block humidity entry and cause the aridity of these deserts. Wind as a dominant process in the area causes deflated features such as Reg (desert pavement), Kalut (Yardang), Hoodoo and wind deposited features such as different kinds of sand dunes and Loess, most of which exhibit beautiful landscapes suitable for ecotourism and scientific tours. Salt deserts, Kavir or Playas, in the lowest parts of internal depressions are the most current features in Iran deserts. The most extensive and specific salt deserts are pathways of floods, which consist of fine grained sediments in the lowest parts of the depressions.
In the above-mentioned areas, there are vulnerable regions to desertification due to extensive use of drylands and increasing population pressure on land and water resources. Overgrazing of Iran’s rangelands is a particular problem. The issue of desertification must be taken seriously and combated using the most available scientific techniques, such as revegetation and windbreaks with domestic plants. Plans to combat moving sands must happen with sufficient technical planning prior to any action.
According to the researches carried out by Iran’s climatological institute, which underlines the role of human activities as well as natural phenomenon on accelerating desertification over the past five decades, on average precipitations decreased by 11 millimeters in the country in each decade, evaporation rates soared by 54 millimeters per decade and temperature rose by 0.4 degrees every 10 years.
In Iran, the rate of desertification is “high,” over 20% of the country’s land is exposed to desertification. Desertification has threatened 18 provinces and 97 cities of the country, and in these arid and semi-arid regions its risk is increasing.
There are different forces including overgrazing, land use change, improper land management, drought, reduced precipitation, soil salinity, overpopulation, erosion, water logging, overuse of pesticides and fertilizers, inappropriate tillage, improper irrigation, and decreased soil fertility causing desertification. However, among all, lack of actions of various governmental institutions within the past five decades, choosing wrong policies and especially the influence of IRGC in every aspect of country’s affair are the main contributors to desertification in Iran.
* Khalil Khani is an Environmental Specialist and a Human Rights activist. He holds a Ph.D. in Ecology, Botany, and Environmental Studies from Germany and has taught at the University of Tehran and the Hesse State University in Germany. He is also a Doctor of Medical Psychology from the United States.