How Is Land Degradation Effecting Iran Environmental Sciences Essay

For the centuries, land debasement is one of the major planetary jobs, particularly in dry lands. Therefore, land debasement influences nutrient security and life quality. Its consequence is on-site or off-site ; the major on-site impact is the diminution of productiveness and land quality in the affected countries. Off-site impacts include deposit and contaminations brought in Lowlandss or deposed in finish. About land debasement rate, there are two point of views. First group including ecologists, dirt scientists, and agronomists believes land debasement as the serious planetary menace that is happening badly in the Earth, while the other position, by economic experts, does non see earnestly about land debasement jobs ( Eswaran, et al. , 2001 ) .

Desertification ; nomenclature and constructs

Initially, in ordinary idea, all or some of the parts in waterless parts called desert ; nevertheless, respects to climatology positions, merely hyper-arid parts are histories for desert. Therefore, the climatic desert ( dry lands and hyper-arid ) covers some about half of countries in the lands of the universe, which is the largest and the most extended biome ( bio-climatic parts ) . Beyond longitude and latitude, the variant sorts of desert lands dispersed universe widely, for the fact, in order to specify desert, it is used the overall and public context, frequently non-quantified. For case, desert is defined in Webster Encyclopedia as “ waterless land with normally thin flora ; particularly: such land holding a really warm clime and having less than 25 centimetres ( 10 inches ) of sporadic rainfall yearly “ or in Britannica Encyclopedia, desert is “ any big, highly dry country of land with thin flora. It is one of the Earth ‘s major types of ecosystems, back uping a community of typical workss and animate beings specially adapted to the rough environment ” .

The term “ desertification ” is foremost referred by Aubreville ( 1949 ) to depict land glade, deforestation, and change overing tropical rain forest ( with average precipitation about 700 – 1500 millimeter ) to harvest lands. Subsequently, sing human activities and clime alterations such as drawn-out or frequent drouths, which are worsening land debasement, desertification is officially defined as “ land debasement in waterless, semi-arid, and dry sub-humid countries ensuing from assorted factors, including clime alteration and human activities ” ( UNCED, 1992 ) , which is used as the footing of the United Nations Convention to Combat Desertification ( UNCCD ) . In this definition, land debasement, clime alterations, and human activities are considered.

Aridity index is the ratio of average one-year precipitation ( P ) as input wet to intend one-year Potential Evapotranspiration ( PET, possible vaporization from dirt plus transpiration by workss ) as wet loss, which was applied by UNEP to sort waterless parts. Consequently, the universe is divided into six fruitlessness zones ( Table 1.1 ) : hyper-arid, waterless, semi-arid, dry sub-humid and humid zones ( WRI, 1999 ) .

Table aˆZ1.1 Categorization of the parts based on fruitlessness index ( in per centum ) ( WRI, 1999 )

Climate zone






& lt ; 0.05


Dry land











Dry sub-humid





& gt ; 0.65


Arid, semi-arid, and dry sub-humid countries, which compose dry lands, refer to the parts with the ratio of precipitation ( P ) to possible vaporization ( PET ) in the scope of 50 to 65 per centum, excepting Highlandss, and the semi-polar or polar parts.

Harmonizing to the United Nations Convention to Combat Desertification ( UNCCD ) , dry lands cover about 90 per centum of Iran ( Table 1.1 ) , where more than half of dry lands are waterless lands, followed by semi-arid countries and so dry sub-humid lands, severally ( WRI, 1999 ) .

Affected countries mean the damaged or threatened countries by desertification procedures in waterless, semi-arid and dry sub-humid lands.

Desertification combating is all activities include the comprehensive sustainable land development in order to forestall or cut down land debasement, the renewal of partially degraded lands, or to the full the affected lands in waterless, semi-arid and dry sub-humid lands. In other words, desertification combat is all activities in the model of comprehensive development undertakings in dry lands, which are based on the rules of sustainable land development including inhibiting, betterment, and renewal activities. The repressive activity includes consciousness, encouragement, and punitory activities. Improvement is the development of cultivation methods, the reformation of irrigation systems, the scene of fallow harvest rotary motion agenda, and the betterment of fertiliser methods.

Reclamation is typically used in the earnestly damaged countries, which is an activity to reconstruct the old normal ecological conditions by execution proficient undertaking such as shelterbelts or windbreaks, and H2O supply.

In literature, there are a batch footings whose definition are similar such as dirt debasement, land debasement, and desertification. Even though land and dirt are clearly defined, nevertheless there are uncertainness and vagueness between debasement and desertification. Harmonizing to the United Nations Environment Program ( UNEP, 1994 ) , the term “ desertification ” refers land debasement in waterless, semi-arid, and bomber humid country due to human activities ( Darkoh, 1998 ) .

In past, the thought about desert extension ( desertification ) considered that desertification is such a physically dynamic, unsafe and rampant phenomenon that makes ecosystems useless or ; hence, this country are low valuable ecosystems without efficiency or capableness.

Consequently, in order to take comeuppances, or to vegetate and do it green, a batch extremist enterprises have been executed, particularly in the cardinal dry lands of Iran. Even these points of positions appeared practically as researches such as the grading and stabilizing of sand dunes and the utilizing of them as croplands or the constitution of green belt in the border of comeuppances, and the biological and mechanical preservation of inclines. The attempts and attacks were mechanical. Subsequently with the following scientific progresss in the variant kingdom and the addition of human ability in the reevaluation of past researches, the point positions are changed into that dry lands or hyper-arid lands are natural ecosystems, in retrospect.

Despite the importance of the environmental and socio-economic impact of desertification, non many attempts have been made to invent the diagnostic techniques and standards for measuring the position and tendency of desertification. The bing surveies have been oriented in a planetary position ( FAO/UNESCO/WMO, 1977 ) , ( Berry, et al. , 1977 ) , UNEP, 1994 ) and most of them were chiefly directed to rangeland conditions in developing states ( Rubio, 1991 ) .

There are two commissariats to measure land debasement surveies:

First, about unequal and unneeded lands or severely affected countries, their capableness and suitableness have to be over than the minimal threshold productiveness ; in other words, its suitableness category must non be excessively worse and lower than the least determined threshold.

Second, about the high quality lands, their capableness in productiveness category must non be more than the determined threshold.

For this ground, the hyper-arid lands due to miss of productiveness ( the first status ) and the humid parts owing to high productiveness ( the 2nd status ) can non be subjected to the desertification issues. However, the necessary status is the being of an external agent to trigger, which renders lands to alter sharply, and irreversibly ; that external cause can be induced by clime alteration or the impacts of human activities on ecosystem.

Soil desertification

There are many types of dirt desertification such as physicochemical impairment, eroding, and H2O logging ( Mbagwu, 2004 ) .

The biophysicochemical impairment and eroding are active dirt desertification in the survey country. The most common types of chemical impairment in farming areas are alimentary losingss and secondary salinisation ( secondary salt of dirt ) . The physical impairment in dirt occurs chiefly through the compression by the agricultural machinery tools, vehicles transit and through the compression of surface soil, which are ensuing partially from misdirection and partially from the natural procedures.

The physicochemical features of dirt are the most of import factors in desertification rating. In this respect, salinisation known as alkalisation or sodification is one of the major desertification indexs in dry lands, particularly in Lowlandss and the cultivable countries. The incorrect irrigation systems in annoyance countries and the rise of groundwater in Lowlandss, attach toing with low rainfall and high vaporization, increase the hazard of desertification ( JRS, 2010 ) .

Water logging is besides an of import dirt debasement cause associated with possible salt jeopardies that might happen through misdirection in lowland.

Soil eroding is such a deciding agent in land capableness and land suitableness rating that frequently in scoured lands, output per unit surface lessenings and the frequence of destructive inundations reaches the largest points.

Status of dirt desertification in the irrigated or dry farms

In the irrigated or the rain-fed farms, some parts of land debasement are related to natural factors and the other parts are relevant to set down development policies. Therefore, the development manners, irrigation systems, the cultivated land methods, and harvest rotary motion are significant in the debasement of agricultural lands.

In the survey country, most inclining lands have been ploughing in the same way of gradient, which are finally abandoned after devastation or loss of birthrate. Generally, incline, dirt deepness, and dirt susceptibleness to eroding are of import factors in dirt debasement in agribusiness lands. So that the incorrect development and the land usage policies or the ignorance of proficient processs in ploughing and harvest triggers land debasement procedures.

In Iran, irrigation serves about one-half of entire cultivated countries in the state, equals 8 million hectares ( hour angle ) . Most cultivable and arable lands suffer from the absence or deficit of H2O. Therefore, the handiness of agricultural land is less restraint for development than the handiness of H2O. The Qanat ( or Ghanat ) , traditional irrigation system, was developed old ages ago, represents advanced methods to face with the abrasiveness of hostile climatic conditions in the state, where land usage policies and irrigation methods are important. The chief causative factors of dirt desertification in croplands or rangelands are overuse and misdirection ( Moameni, 2001 ) .

Status of dirt desertification in wood and grazing land

The quality and measure of flora of course are affected by clime and dirt conditions ; hence, due to the rough clime and utmost conditions in desert-like parts, there exist merely some adapted workss. Even misdirection and the overexploitation of lands are the chief ground of desertification ; fuel wood, overgrazing, and the cultivation of dry lands decrease the extent of green land screen. In add-on, the addition of aggressive workss affects flora quality in grazing lands, whose quality decreased due to overgrazing by farm animal, or busying with invasive and low-quality grasses.

Harmonizing to literature studies and field groundss, grazing land and rangelands in Kashan countries are in negative tendencies. It genuinely seems that the most aggressive dirt and land debasement occur in grazing lands, so that human-induced desertification is chief causative factor, while natural and climatic factors are following in rank ( Jafari, et al. , 2002 ) ( Shamsipour, et al. , 2005 ) .

The acknowledgment of the factors involved in wood and grazing land debasement helps extinguish or command their effects. The most of import lacks in rangeland policies are deficiency of ownership or determined beneficiary in term of office system, early and premature graze in spring, overgrazing by farm animal, and change overing grazing lands to dry farms.

Land debasement in semi-dense wood is brought by deforestation, the remotion of wood, and overgrazing. Despite the fact, land debasement has non been yet a affair of concern at national degree in Iran ( Moameni, 2001 ) ( Sombroek, et al. , 1993 ) .

Extent of desertification in Iran and its importance

Presents, the desertification phenomenon has so extended consequence over ecosphere that has been beyond the primary imaginativeness of Lavvden ( 1949 ) and Aubreville. It is non limited merely on the enlargement or motion of comeuppances, so, desertification job is land debasement, where occurs even out of desert lands. Land debasement appears as the lessening of dirt productiveness, the diminution of groundwater quality and its measure, the addition of land ‘s sensitiveness to eroding, the addition of inundations, the being buried of dikes and the lessening of its efficiency, salinisation, and flood ( Dregne, 1983 ) .

Consequently, dirt remotions and the exposure of bare land lead to biodiversity riddance and finally, in-migration and destroy lives. Even in European states, land debasement occurs ; this continent has lost more than one one-fourth of its dirt from the entire European lands of which 60 % is due to increasing flora debasement ( van Lynden, 2004 ) . Therefore, sing the importance of desertification as one of major jobs in the universe, it is non possible to work out desertification jobs without the dependable methods for the evaluating and exploring of variant signifiers of debasements ( Lal, et al. , 2004 ) .

Iran is over the Equus caballus latitudes, the hot and dry belt of latitude. Therefore, as the 10th driest state in the universe, the hyper-arid and waterless clime zones cover most of the state. In fact, Iran is such a susceptible state that every twelvemonth catastrophes such as eroding, inundation, drouth, and landslide convey many economic, societal, and natural jobs.

Harmonizing to International Strategy for Disaster ReductionA ( ISDR ) studies:

“ In Iran one time due to a drought incident in 2001, approximately 37 million people have been affected. Water militias in the state were reduced by 45 per centum, approximately 800,000 caputs of farm animal were lost in 2000, and 2.6 million hectares of irrigated land and 4 million hectares of rain-fed agribusiness were affected. Damage to agribusiness and farm animal was estimated by the United Nation ( UN ) about US $ 2.5 billion in 2001 and US $ 1.7 billion in 2000 ” ( UN/ISDR, 2004 ) .

In the last decennaries, the sufferings of desertification and drouth have to a great extent influenced the development planning in Iran, whereas, for which the allotment of the national budget in the Second Five-Year Development Plan ( 1995-1999 ) spent about 51 million US dollars.

Simultaneously, NGO ( Nongovernment Organization ; the private divisions and local communities ) has invested about five million US dollars ; to boot the conservative activities of substructures such as residential and industrial lands every bit good as path system against sand dunes motion have taken as added portions in the national budget.

In the late eightiess, the irrigated land damaged by salinisation ( as secondary salt by irrigation ) , which is brought by lifting in H2O degrees of groundwater and the mobilisation of salts, reaches 17000 km2, which is 30 % of irrigated land in Iran. As the most bulk of irrigated lands in Iran are saline, and productiveness depressed by the toxicity of salt.

Because of different definitions in the literatures, there are differences about the extent of dry lands in Iran. Harmonizing to fruitlessness index ( Table 1.1 ) , the country of dry lands in Iran is about 1.466 million km2 ( out of 1.624 million km2 ) , approximately 90.3 per centum of the state ( WRI, 1999 ) .

Meanwhile, respects to De Martonne index, the ratio of precipitation to temperature, the country of dry lands reaches 53.9 per centum, and hyper-arid country and humid zones cover 35.2 per centum and 8.9 per centum, severally ( Khalili, 1992 ) . Harmonizing to the United Nations Convention to Combat Desertification ( UNCCD, 1998 ) , the affected countries are over 43 per centum of the state. The country affected by dirt eroding reaches 37 per centum of the state ; H2O eroding in Iran is about 26.4 million hectares, and air current eroding is about 35.4 million hectares, 16 and 21 per centum of the state, severally. Therefore, land debasement rate is really terrible ( Lai, 2001 ) .

Dry lands in Iran support the half population of the state and incorporate big metropolis metropoliss such as Mashhad and Tehran. Therefore, determination shapers, research workers considerate solutions, directions, and environment policies ( Pakparvar, 1998 ) .

Remote detection and desert

Since the visual aspect of aerial photogrammetric and remote feeling methods, which are brought out many advantages, there have been many involvements in the perusal and the investigation of natural phenomena. Most of involvements are oriented toward the function and apprehension of locale fluctuations of landforms and geomorphic procedures.

Distant feeling includes a broad spectrum of public-service corporations to research natural environment and to place the happening of phenomena such as land alteration or debasement. Particularly, the novel implemented detectors, which are capable to find land surface temperature or flora position, aid explore and detect environmental catastrophes such as drouth, and desertification. Particularly, holding thermic detectors makes them possible to supply thermic maps easy. Thermal informations are efficient resources to look into and measure the natural resources in planetary, national and regional graduated table, particularly in dry lands. Chiefly, holding these capablenesss is singular in topographic points without climatology Stationss or barely handiness such Central Iran, in where desertification is one of the most serious societal, ecological, and environmental jobs, particularly, which have been under-consideration by the populace and scientific research workers.

In fact, in order to accomplish sustainable development and better decision-making we need suited and up-to-date information approximately phenomena every bit good as the realizing of inter-relationships of in environmental variables.

The high serviceability, temporal handiness, and extended coverage of images acquired by remote feeling have been the topic of many surveies used to look into the procedures and phenomena.

In Iran, there have been many remote feeling surveies. Inevitably, the most accessible countries are studied more ; nevertheless, inhospitable and unaccessible countries by and large are neglected.

Before the 18 century, maps were based on Ptolemy ‘s geographics, and there are rare paperss about the powerlessness of environmental issues except few studies about some events such as drouths and dearths, which people died because of some misdirection, famishment and deficit of nutrient production. Recently, it is started learning by the establishing of the western-formed instructions in Iran.

The nineteenth century was the beginning for new scientific discipline by taking aerial exposure. Bladford ( 1873 ) provided a map of Southwest Asia including some of import characteristics of cardinal Iran such as Great Kavir, and Lut desert. Huntington ( 1905 ) explored the historical stratigaraphic groundss, and interpreted the beginning of waterless clime at the terminal of the Tertiary, which is followed by a wet era. He concludes that southeasterly Iran has experienced a alteration from a more humid clime during classical times to its present waterless clime ( Krinsley, 1970 ) .

At the get downing twentieth century, Walther ‘s surveies showed the relationship of clime to come up morphology and generation. Desio ( 1943 ) , Bobek ( 1963 ) and Wright ( 1961 ) , by land surveying and researching provided geological maps, specifically, glacial sedimentations in the Zagros Mountains which they considered to be Wurm ( Wisconsin ) age. Bobek and Wright ( 1963 ) have found grounds for a pre-Wurm glaciation of the Zagros and Elburs Mountains ( Krinsley, 1970 ) .

Huber ( 1960 ) by executing seismal sounding and boring in Qom Playa revealed a lower subdivision about 350 m thick and upper subdivision which is 46 m midst near the Centre of the playa. The lower subdivision consists of a basal bed of medium to farinaceous sand, gypsum and andesitic grit. This is covered by brown and green clays with 10 to 25 per centum of clear salt crystals. The larger upper portion of the lower subdivision contains brown clay and silt.The upper subdivision consists of an alternating of five salt beds with intercalated beds of brown or green clay and silt and two sand skylines. The upper subdivision pinches out at the borders of the playa and some members are absent. Neither faunal nor flowered informations permit an effort at an absolute chronology. Huber ( 1960 ) concluded that the lower subdivision was deposited under a perennial H2O screen that was non rather concentrated salt H2O and was non precipitating any salt members. He reasoned that the upper subdivision represented alternativengly true evaporites and impermanent lake deposits under conditions compatible with the existent clime ( Krinsley, 1970 ) .

After establishing Landsat 1, first mission of the Earth Resources Technology Satellite ( ERTS ) series in 1972, and new epoch of distant detection appeared. Its public-service corporations in land study and land direction helped the research workers to use digital images to explorer huge environment.

Research hypotheses

In order to develop a new algorithm and to measure the public-service corporation of remotely sensed informations in dry lands, the hypotheses of the survey are chosen as follows:

Desertification is possible to be parameterized based on tools such as orbiter informations and auxiliary spatial informations, by which can be extracted some utile indices to gauge desertification conditions based on thermic and brooding sets.

The utilizing of the integrated fuzzy illation system and remote detection in land rating practically is helpful to get cognition about desertification theoretical account.

Research inquiries

Following research inquiries for the end of the survey have been made:

How desertification occurs in response to flora and dirt index over long-run period?

What is the spacial and temporal form of desertification in the survey country?

Is there any association and relationship among flora, dirt and clime indexes?

How apply desertification hazard can be evaluated by the combination of satellite images and accessory informations in fuzzed illation system?

How is illustrated the incorporate fuzzed systems and distant detection in desertification rating?

Research aims

The undertaking intent is to show some public-service corporations of distant feeling informations in the monitoring of dry land, well in the estimating of the causes of natural catastrophes such as desertification and drouth. The challenge consisted of surveies about clime, flora and dirt debasement based on brooding or thermic indexes in distant detection. In this research, we attempt to show semi-linguistic methods in Earth scientific discipline and to happen out that how it is possible to better the survey of desertification rules by the incorporate accessory informations, remote feeling in a fuzzy system theoretical account.

Except some restrictions in research such as the unavailability of the survey country, this research aims to develop an appraisal technique for desertification theoretical account utilizing distant detection and accessory informations, and adept cognition. In other words, the aim of the undertaking is to use the incorporate remote detection and fuzzy system to better decision-making procedure in land rating in dry lands.

In this undertaking are following aims:

To develop a methodological analysis to incorporate spacial remote feeling informations to measure sustainability of dry lands utilizing fuzzed logic theoretical account.

To find the countries akin to debasement by the integrated expert and informations cognition base theoretical account by the combine of orbiter informations and other thematic information. In other words, this research looks for the applications of distant feeling images in desert countries, coupled with a methodological analysis by utilizing fuzzed logic attack.

The chief aims in this undertaking are to measure some standards, to happen out the relationship of these indices, and to build a cognition base theoretical account for desertification phenomena by utilizing distant feeling informations.

Research attack

The research attack is comprised of following stairss:

Supplying multi-temporal informations for get cognition.

Planing of the fuzzed expert systems and analyses of informations to pull out cognition and validate expert cognition.


Vegetation status

Remote feeling


Land screen

Meteorological informations

Dirt and geology


Ancillary informations





Desertification hazard map

Thermal status

Figure aˆZ1.1 The general mythology of undertaking

For this ground, the chief parametric quantities in desertification ( Chapter 2 ) are introduced. The basic information about fuzzy logic is defined ( Chapter 3 ) . Then, to happen out the environment circumstance of the survey country, its chief features are described ( Chapter 4 ) .

Harmonizing to Figure 1.1, two sorts of informations are used, remote feeling and accessory informations. The flora and thermic belongingss of land surfaceA are calibrated in image pressure as indices for desertification. Additionally, land screen map is digitized by the ocular reading of orbiter images, which is used a base map. From accessory informations, three indexes of desertification such as dirt eroding, implosion therapy, and drouth are calculated. Erosion, drouth, and deluging maps are created ( Chapter 5 ) . Then, the analysis of the derived indexes and the designing of fuzzed illation system lead to fix the concluding desertification map ( Chapter 6 ) . Additionally, some subsidiary analyses such as clip series, and spacial analysis in Geographic Information System ( GIS ) are presented in ( Chapter 5 ) .

Dissertation model

This undertaking is composed of seven chapters as the consecutive divisions mentioned below.

Chapter 1, Introduction ; a brief of constructs such as hypotheses, inquiries, research inquiries and aims comprises of the first chapter.

Chapter 2, Desertification indexes ; this chapter discusses the chief indices used in this research to fix desertification map.

Chapter 3 Fuzzy logic ; in this chapter we are discoursing about fuzzed illation system and its constituents to build simple fuzzed systems.

Chapter 4, Study Area ; this chapter gives a brief overview of the survey country belongingss such as presenting land screen types and clime status.

Chapter 5, Implementation of Data and their characteristic screens the stuffs and the description about informations, image processing and spacial analyses.

This chapter besides gives some description about ciphering indexes, which are derived distant feeling informations or accessory. In add-on, by the analyzing of temporal images, it represents how desertification has been happening. The accessory informations and remote feeling informations will assist find desertification. At the terminal, desertification map is prepared based on traditional standards.

Chapter 6, Fuzzy expert system for desertification ; in this chapter, a cognition base system will be implemented. Addition to Fuzzy illation system ( FIS ) , here by analysing of the relationships and correlativities among indices, rule-based system will be discussed that including expert and initiation interface theoretical account to construct a fuzzy expert system. Additionally, by analysing consistence of regulations and the simplification of rule-based system, the entire consequence is represented as a simple cognition based system for desertification by distant detection and accessory informations.

Chapter 7, Conclusion and Recommendations ; the last chapter is decision covering the decision of the survey being done every bit good as restrictions and recommendations for future survey and what could non be handled in this survey every bit good.