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Figure 7. Y early changes in rate of human population and livestock population in Northeast of China (Chen and Tang, 2005)

Figure 7 Y early changes in rate of human population and livestock population in Northeast of China (Chen and Tang, 2005)

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Figure 1. Proportion of man-made factors in development of desertification (UNEP, 1997) explai reducti deserti in dese avail n factors of dese on i ficati roduc rests 1 e the ficati ry sub- ocal wat able resou BS is not li sO p is situa e fo ay b rti nd d nd mB dO t formal oO r resources, rce potential clu mount or diversity of Kadomura, 2001). A salie nly effective factor in developmen igure 1 indicates the contri forests. A pplicati mited to tion i the areas wi and degradati mid areas resu tification but he identified devastatin on of the definiti arid areas. It also n the form of destruc th no biologic values. statement of the factors rela n, in the context of tio ting from adverse d su an rosio natural nce in th on tio face and vege by one or a combinati de water erosion, wind e n and sedimenta vegetation, w is definition is th t of desert areas with bution of each of the hum gh shows that hu n of trees, severe so he definitio ted to thi assessme human im tation o on of on re T nt, pact. Land i rc processes acti Ul here relevant, and Ul N uman activi in a forest area is i man acti n of deserti phenomen is land deg rops. Degradati by those agents, lon ndicative o il erosion, and Based on radation in ari n this concept i on implies on. ng oO g term redu salinization ai ties as the main cause fo f the fact tha vities in vegetated areas ca conversi fication by UNEP in this definition on 0 199( id, semi-aric includes soi reduction o n land. These processe: ction in the nd sodicatio1 at human adverse activities are considered as the o considerable attention to na an activities in global scale by UNEP (1997). tural causes
Figure 1. Proportion of man-made factors in development of desertification (UNEP, 1997) explai reducti deserti in dese avail n factors of dese on i ficati roduc rests 1 e the ficati ry sub- ocal wat able resou BS is not li sO p is situa e fo ay b rti nd d nd mB dO t formal oO r resources, rce potential clu mount or diversity of Kadomura, 2001). A salie nly effective factor in developmen igure 1 indicates the contri forests. A pplicati mited to tion i the areas wi and degradati mid areas resu tification but he identified devastatin on of the definiti arid areas. It also n the form of destruc th no biologic values. statement of the factors rela n, in the context of tio ting from adverse d su an rosio natural nce in th on tio face and vege by one or a combinati de water erosion, wind e n and sedimenta vegetation, w is definition is th t of desert areas with bution of each of the hum gh shows that hu n of trees, severe so he definitio ted to thi assessme human im tation o on of on re T nt, pact. Land i rc processes acti Ul here relevant, and Ul N uman activi in a forest area is i man acti n of deserti phenomen is land deg rops. Degradati by those agents, lon ndicative o il erosion, and Based on radation in ari n this concept i on implies on. ng oO g term redu salinization ai ties as the main cause fo f the fact tha vities in vegetated areas ca conversi fication by UNEP in this definition on 0 199( id, semi-aric includes soi reduction o n land. These processe: ction in the nd sodicatio1 at human adverse activities are considered as the o considerable attention to na an activities in global scale by UNEP (1997). tural causes
Figure 2. cycle of subsidiary processes of desertification such as soil erosion (by wind and water) and the primary process of drought (climate) based on vegetation destruction (D’Odorico, et al 2013). more water for dilution of the resources. This trend may continue to cause salinization < destruction of agricultural lands. On the contrary, we have subsidiary processes of desertificatio desertification. These processes do not play a major role i desert development. Indeed, after the occurrence of pri n desertificatio mary p (OCESSES overgrazing, non precision agriculture, and salinization, a severe destructio and vegetation may be emerged. The result of these processes wou he subsi ral envi f vegeta processes of desertification, e.g. water and wind erosions. T and the primary factor of drought are at the cycle of natu desertification. The terret of these processes is the amount of di d be activa ary processe ronment tion (Figure 2). di F bi tio n of nin n that can be results of | n in the in of desertification, € ological resour itial stages the subsidi: s of desertificati teraction w
Figure 2. cycle of subsidiary processes of desertification such as soil erosion (by wind and water) and the primary process of drought (climate) based on vegetation destruction (D’Odorico, et al 2013). more water for dilution of the resources. This trend may continue to cause salinization < destruction of agricultural lands. On the contrary, we have subsidiary processes of desertificatio desertification. These processes do not play a major role i desert development. Indeed, after the occurrence of pri n desertificatio mary p (OCESSES overgrazing, non precision agriculture, and salinization, a severe destructio and vegetation may be emerged. The result of these processes wou he subsi ral envi f vegeta processes of desertification, e.g. water and wind erosions. T and the primary factor of drought are at the cycle of natu desertification. The terret of these processes is the amount of di d be activa ary processe ronment tion (Figure 2). di F bi tio n of nin n that can be results of | n in the in of desertification, € ological resour itial stages the subsidi: s of desertificati teraction w
Figure 3. Desert regions and the regions under the influence of desertification (United States Department of Agriculture, 1998) It is important to note the geographical distribution of regions under the in . The spatial distribution of desert areas (gray color) and the areas suscep (Figure 3 development (red color) show concentration of these areas in WAR and cen These conditions make it necessary to pay more attention to the investigatio in occurren prevent these areas from converting into desert areas and from their attach to WAR, United States of America, North of Africa, North of China are ei In addition ce of this phenomenon in WAR. This is for finding appropri influence of desert conditions or in transient stages into these areas. fluence of desertification tral Asia (U ns about eff tible to desert SDA2, 1998). fective factors ate solutions in order to ment to adj acent deserts. ther under the
Figure 3. Desert regions and the regions under the influence of desertification (United States Department of Agriculture, 1998) It is important to note the geographical distribution of regions under the in . The spatial distribution of desert areas (gray color) and the areas suscep (Figure 3 development (red color) show concentration of these areas in WAR and cen These conditions make it necessary to pay more attention to the investigatio in occurren prevent these areas from converting into desert areas and from their attach to WAR, United States of America, North of Africa, North of China are ei In addition ce of this phenomenon in WAR. This is for finding appropri influence of desert conditions or in transient stages into these areas. fluence of desertification tral Asia (U ns about eff tible to desert SDA2, 1998). fective factors ate solutions in order to ment to adj acent deserts. ther under the
Use of the term “population changes” as one of the main factors of desertification, here, implies that not only the increasing of population density may destroy biologic resources but, in some cases, the population decrement due to human casualties and group migration (Exodus) can also develop the borders of desert regions.
Use of the term “population changes” as one of the main factors of desertification, here, implies that not only the increasing of population density may destroy biologic resources but, in some cases, the population decrement due to human casualties and group migration (Exodus) can also develop the borders of desert regions.
Movement of popula completely devastate n other words, leavi C lands r development tion, particulal lands is an of for is resul e most need for resu icult to combat com obal, national and financial pop’ paying n and dust storm. Given the relative similarities of the dust storm phenomena and sources, we can learn from support, and educa ulation in damaged areas. O attention to the req motives in the n and rehabilita organizations te local peo local s may be m additional problem that m ng of devastated lands and concentrati desert condition in both the immigrant the number of people w e to deserti y in the regi effects of political and social issues cannot be igno inly because of destruction dents of desert and semi desert areas. O they mai opment al nage to im ocal people and ent of desert borders. As a tion of damaged formulate plans Although, fication. Most of the peop ons of Afni of desert condition. rehabilitation. On the contrary, in cases It of a lack of enough developm bat the desertificatio to contro ple. These plans may aim it takes a long time to real uirements may weaken other methods of man akes it hard ori ho tend to migra can Sahara, cou n the o the pas s is whi from Thi migrate where tl ow attention of gove origin te permanently is high in e will ntries of natu he people cai rly in permanent form, and leaving after human activities that may mpossible to rehabilitate. on of population in adjacent areas makes s and destinations. h the tendency to in the WAR, and red in the tendency ral resources as the ther hand, regardless ture and agricultural e; these lands are in nnot immigrate, as a mments, it would be e of th that tl popu to p ize su result, on areas is e pri ation he governments and oll revent sudden changes ch goals, but it seems that agement of desertificati ncipal approaches to her rate, provide aimed in on the
Movement of popula completely devastate n other words, leavi C lands r development tion, particulal lands is an of for is resul e most need for resu icult to combat com obal, national and financial pop’ paying n and dust storm. Given the relative similarities of the dust storm phenomena and sources, we can learn from support, and educa ulation in damaged areas. O attention to the req motives in the n and rehabilita organizations te local peo local s may be m additional problem that m ng of devastated lands and concentrati desert condition in both the immigrant the number of people w e to deserti y in the regi effects of political and social issues cannot be igno inly because of destruction dents of desert and semi desert areas. O they mai opment al nage to im ocal people and ent of desert borders. As a tion of damaged formulate plans Although, fication. Most of the peop ons of Afni of desert condition. rehabilitation. On the contrary, in cases It of a lack of enough developm bat the desertificatio to contro ple. These plans may aim it takes a long time to real uirements may weaken other methods of man akes it hard ori ho tend to migra can Sahara, cou n the o the pas s is whi from Thi migrate where tl ow attention of gove origin te permanently is high in e will ntries of natu he people cai rly in permanent form, and leaving after human activities that may mpossible to rehabilitate. on of population in adjacent areas makes s and destinations. h the tendency to in the WAR, and red in the tendency ral resources as the ther hand, regardless ture and agricultural e; these lands are in nnot immigrate, as a mments, it would be e of th that tl popu to p ize su result, on areas is e pri ation he governments and oll revent sudden changes ch goals, but it seems that agement of desertificati ncipal approaches to her rate, provide aimed in on the
Desert areas of China and the areas susceptible to desertificatio of this country (Figure 6), have covered about 34 % of the country (Lu et al, 2006). 00 km?/yr in 1980s (Zhu desertification was 1560 km*/yr in 1970s (Zhu, 1985), about 2 1990) and about 2460° km*/yr in 1990s (CCICCD’, 1997). In with cooperation of international organizations was successful to decrease the ris desertification taken to control and reduce desertification are failed and the decrease might be limi portions of Ch n, mainly located in the the past decade, Chinese to 2000 km*/yr (UNCCD, 2011). However, som ina (Chen and Tang, 2005). e researchers believe tha northern par Here, the rate o: and W ang governmen ing trend o. t the action: ted to som The population growth is estimated to be less than 10 % till 2025 in China (Figure 4). The policy of increment in birth rate is not limited to recent years. It was specifically from 1611 to 1911, as the main policy of government (Qing Dynasty). The policy was also followed in desert and semi desert areas in north of China. The government had to make some secondary decisions. Some of these decisions were that the government had encouraged residents of the regions to change the land uses of the pastures. It was conducted in the form of three landuse change operations from 1802 to 1930. The realization of the planning that was inconsistent with environmental potential of these vulnerable areas not only destructed the soil and its biological characteristics, but it exerted an ever increasing p p ressure upon the environment. This was in condition that the food requirements of the dense opulation make it necessary to develop their ranching (Figure 7). Making such decisions in 1950s and 1970s as macro-level economic plans with the name of “Great Leap Forward” and “Grain as Key Link” resulted in changes in land uses of pastures with low productivity and their devastation (Zhou,
Desert areas of China and the areas susceptible to desertificatio of this country (Figure 6), have covered about 34 % of the country (Lu et al, 2006). 00 km?/yr in 1980s (Zhu desertification was 1560 km*/yr in 1970s (Zhu, 1985), about 2 1990) and about 2460° km*/yr in 1990s (CCICCD’, 1997). In with cooperation of international organizations was successful to decrease the ris desertification taken to control and reduce desertification are failed and the decrease might be limi portions of Ch n, mainly located in the the past decade, Chinese to 2000 km*/yr (UNCCD, 2011). However, som ina (Chen and Tang, 2005). e researchers believe tha northern par Here, the rate o: and W ang governmen ing trend o. t the action: ted to som The population growth is estimated to be less than 10 % till 2025 in China (Figure 4). The policy of increment in birth rate is not limited to recent years. It was specifically from 1611 to 1911, as the main policy of government (Qing Dynasty). The policy was also followed in desert and semi desert areas in north of China. The government had to make some secondary decisions. Some of these decisions were that the government had encouraged residents of the regions to change the land uses of the pastures. It was conducted in the form of three landuse change operations from 1802 to 1930. The realization of the planning that was inconsistent with environmental potential of these vulnerable areas not only destructed the soil and its biological characteristics, but it exerted an ever increasing p p ressure upon the environment. This was in condition that the food requirements of the dense opulation make it necessary to develop their ranching (Figure 7). Making such decisions in 1950s and 1970s as macro-level economic plans with the name of “Great Leap Forward” and “Grain as Key Link” resulted in changes in land uses of pastures with low productivity and their devastation (Zhou,
Figure 8. desertification vulnerability of Africa (Jones, et al 2013).
Figure 8. desertification vulnerability of Africa (Jones, et al 2013).
Figure 9. Population growth in Africa from 1900 to 2000. (@) represents population of arid areas in th south of Sahara Desert, (™) east A frica, (a) Sahel Region, and (*) South Africa from 1190 to 2000 (Le Houérou, 1996)°. men in Mali have migrated cap neighboring regions. In this area people were af and development of desert boundaries. rs, have led to complete tion areas of migra ught conflic idental. income severity of poverty i people to u causes inte society redu natural reso natural reso ts and i ral resou h the margi icates incon TCes WOVE. tilize intens nsification of urces to meet nternational wai in destinati untries with the most poverty inc nal areas of Sahara Dese ndeed, severe poverty in a population mo rtible role of dese resources of human popu s due to desertificatio ively envi desertifi ces access to lands and ca urces. It is while, the people li their basi cti ation. ronmental cation. In uses rel vin c needs rt which into neighboring countries or Eu ital of Kenya) has experienced an increase of 800 percent in Popu. tion ( mos Furthermore, resources to fact, in these extinctio Darkoh, 1 uding Mali, Niger, Central Africa, and Chad are coinci tly aff his cannot be re tha fication in destructi 998). n 40 percent be uctance among peop g near the regions a UNCCD, 2011, UN, 2007, Darkoh, 1998). meet their region e to ected by desertification. T on of environmental resou it must n, but this phenomenon serv of people in these cou mentioned that not on e as a factor that make requirements. In return s, the poverty prevailing on (ces, 1.€. rope. On the opposite, Nairobi (the population due to immigration from flicted from 1963 to 2005 by poverty as a result of ation changes, may be as result of internecine n of abandoned areas and destruction N q the earn optimal ways for use of re dependent upon exploitation of
Figure 9. Population growth in Africa from 1900 to 2000. (@) represents population of arid areas in th south of Sahara Desert, (™) east A frica, (a) Sahel Region, and (*) South Africa from 1190 to 2000 (Le Houérou, 1996)°. men in Mali have migrated cap neighboring regions. In this area people were af and development of desert boundaries. rs, have led to complete tion areas of migra ught conflic idental. income severity of poverty i people to u causes inte society redu natural reso natural reso ts and i ral resou h the margi icates incon TCes WOVE. tilize intens nsification of urces to meet nternational wai in destinati untries with the most poverty inc nal areas of Sahara Dese ndeed, severe poverty in a population mo rtible role of dese resources of human popu s due to desertificatio ively envi desertifi ces access to lands and ca urces. It is while, the people li their basi cti ation. ronmental cation. In uses rel vin c needs rt which into neighboring countries or Eu ital of Kenya) has experienced an increase of 800 percent in Popu. tion ( mos Furthermore, resources to fact, in these extinctio Darkoh, 1 uding Mali, Niger, Central Africa, and Chad are coinci tly aff his cannot be re tha fication in destructi 998). n 40 percent be uctance among peop g near the regions a UNCCD, 2011, UN, 2007, Darkoh, 1998). meet their region e to ected by desertification. T on of environmental resou it must n, but this phenomenon serv of people in these cou mentioned that not on e as a factor that make requirements. In return s, the poverty prevailing on (ces, 1.€. rope. On the opposite, Nairobi (the population due to immigration from flicted from 1963 to 2005 by poverty as a result of ation changes, may be as result of internecine n of abandoned areas and destruction N q the earn optimal ways for use of re dependent upon exploitation of
Golden p with severe drought of this period. As it can 00 years period indicates decline of rainfall i mean of reas of the United S of vast plains and re and ranching. Unti livestock were deve eriod of productivity re areas were intensively used for oped so that the economy of local people were more than eve y vegetation, tates towards th rangelands are 1930s as a res agricul t upon use of natural resources, pai ticular! e south of the cou characteristics of the region where are suitable fo: ult of World War Ii ture, particu n 1930s. ntry. The semi arid climate witl n Europe and wet years in 1920: arly wheat crops. Ranching anc surface and ground water. Th in these agricultural lands suddenly dropped in the beginning of 1930: be observed in Figure 11, deviation of rainfall from the The immediate result of this drought was severe destruction of vegetation and exposure of ploughed soils to swift southern winds. The soils were transformed by southern wind and caused enormous dust storms. These masses of dusts are called “Dust Bowl” or “Dirty Thirties” (Hornbeck 2012). Figure 12 illustrate the approximate extent of these storms.
Golden p with severe drought of this period. As it can 00 years period indicates decline of rainfall i mean of reas of the United S of vast plains and re and ranching. Unti livestock were deve eriod of productivity re areas were intensively used for oped so that the economy of local people were more than eve y vegetation, tates towards th rangelands are 1930s as a res agricul t upon use of natural resources, pai ticular! e south of the cou characteristics of the region where are suitable fo: ult of World War Ii ture, particu n 1930s. ntry. The semi arid climate witl n Europe and wet years in 1920: arly wheat crops. Ranching anc surface and ground water. Th in these agricultural lands suddenly dropped in the beginning of 1930: be observed in Figure 11, deviation of rainfall from the The immediate result of this drought was severe destruction of vegetation and exposure of ploughed soils to swift southern winds. The soils were transformed by southern wind and caused enormous dust storms. These masses of dusts are called “Dust Bowl” or “Dirty Thirties” (Hornbeck 2012). Figure 12 illustrate the approximate extent of these storms.
Figure 12. the areas under the influence of dust storm of 1930s. Dust Bowl in Great Plains (Baumhardt, 2003) Truth Findi prevalence of inconsistent occurrence of values of agri ng Committee respons influence of cli f agriculture and y in F du cu cultivation of wi lands into s Baumhardt, 2 mal cultivation, and It is notewortl hy that with occurre ib mate change in form ranc st storm events inc tural products and hing activities semi arid climate of this regi subsequent re e for researc ation of this event. udes: rigorous econ ease of nter wheat, in that er pieces, preval nce of more severe drought h about this phenomenon that were special to humi on. Some causes stated for soil this prevent saving of water ence of feudalism finally the severe drought in the form 003). rejected the hypothesis of tributed this happening to d climates and propagated destruction and omic stagnancy of 1930s, sharp decrease in cultivated lands, prevalence of one product in summer, division of agricultural , repeated movements of soil in climate fluctuations (Lockeretz, 1978, The co mmittee a renting 6) c event in 1950s relative to 1930s (Figure
Figure 12. the areas under the influence of dust storm of 1930s. Dust Bowl in Great Plains (Baumhardt, 2003) Truth Findi prevalence of inconsistent occurrence of values of agri ng Committee respons influence of cli f agriculture and y in F du cu cultivation of wi lands into s Baumhardt, 2 mal cultivation, and It is notewortl hy that with occurre ib mate change in form ranc st storm events inc tural products and hing activities semi arid climate of this regi subsequent re e for researc ation of this event. udes: rigorous econ ease of nter wheat, in that er pieces, preval nce of more severe drought h about this phenomenon that were special to humi on. Some causes stated for soil this prevent saving of water ence of feudalism finally the severe drought in the form 003). rejected the hypothesis of tributed this happening to d climates and propagated destruction and omic stagnancy of 1930s, sharp decrease in cultivated lands, prevalence of one product in summer, division of agricultural , repeated movements of soil in climate fluctuations (Lockeretz, 1978, The co mmittee a renting 6) c event in 1950s relative to 1930s (Figure
(11.9 million hectares), 70 % (3.5 million hectares), and 17 % (110 thousands hectares) (AFED " 2008). Based on these statistics, in both countries of Iraq and Syria range overgrazing and severe degradation of envi degradation in d evaporation ra salinization areas. Accordin other coun experts fro work in identifi entitled G researches, Le, of soil in tries mM en gu obal the the destruc On essment tive agricu low qual Syma i to UNEP re 14) of hu ry and irrigated agricultu ity of irrigation syste s not so high, b 1992) the situati AFED, 2008). U the world and based on i man factors of desertification from 1987 to 1990. The research work of Human-Induced Soil Deg important factor of desertification in sou tural activities and in highlands of Turkey is demolition of forest vegetation. ronment. re lands. This ms, an ut dry farming on is almost si ts own definition In Iraq there d some ands are about to converting in C8 witl radation (GLASOD). ands are under the influence is no difference between la on may be due to enormc times saline water. Althouc to des rivers tists a reseal conditi milar in other basins of these h collaboration of scien of desertification conducted a Based on the th west of Iran and south east of Iraq
(11.9 million hectares), 70 % (3.5 million hectares), and 17 % (110 thousands hectares) (AFED " 2008). Based on these statistics, in both countries of Iraq and Syria range overgrazing and severe degradation of envi degradation in d evaporation ra salinization areas. Accordin other coun experts fro work in identifi entitled G researches, Le, of soil in tries mM en gu obal the the destruc On essment tive agricu low qual Syma i to UNEP re 14) of hu ry and irrigated agricultu ity of irrigation syste s not so high, b 1992) the situati AFED, 2008). U the world and based on i man factors of desertification from 1987 to 1990. The research work of Human-Induced Soil Deg important factor of desertification in sou tural activities and in highlands of Turkey is demolition of forest vegetation. ronment. re lands. This ms, an ut dry farming on is almost si ts own definition In Iraq there d some ands are about to converting in C8 witl radation (GLASOD). ands are under the influence is no difference between la on may be due to enormc times saline water. Althouc to des rivers tists a reseal conditi milar in other basins of these h collaboration of scien of desertification conducted a Based on the th west of Iran and south east of Iraq
Figure 15. land cover of dust cluster in northern part of Tigris and Euphrates Drainages (Darvishi, et al 2012). This basins are coincident with desert regions of northwest of Iraq and southeast of Syria. In recer years dust sources in the regions are extremely active and affected large areas of the WAR especially western and southwestern of Iran and other countries around Persian Gulf (Taghavi an Asadi, 2008, Mofidi and Jafari, 2011). According to Darvishi et al (2012) the dust sources located i: northwest of Iraq and east of Syria are divided into two sub-clusters in terms of their activity an effectiveness on the areas where located in their path, i.e., Iran and countries around Persian Gul (Figure 15). In this division, the dust sources located in Iraq (A) have more activity and frequency o occurrence compared with those located in Syria (B). Based on land cover map of the region, mos part of this cluster of dust is composed of desert and semi-desert regions where are almost devoid o vegetation (Figure 15).
Figure 15. land cover of dust cluster in northern part of Tigris and Euphrates Drainages (Darvishi, et al 2012). This basins are coincident with desert regions of northwest of Iraq and southeast of Syria. In recer years dust sources in the regions are extremely active and affected large areas of the WAR especially western and southwestern of Iran and other countries around Persian Gulf (Taghavi an Asadi, 2008, Mofidi and Jafari, 2011). According to Darvishi et al (2012) the dust sources located i: northwest of Iraq and east of Syria are divided into two sub-clusters in terms of their activity an effectiveness on the areas where located in their path, i.e., Iran and countries around Persian Gul (Figure 15). In this division, the dust sources located in Iraq (A) have more activity and frequency o occurrence compared with those located in Syria (B). Based on land cover map of the region, mos part of this cluster of dust is composed of desert and semi-desert regions where are almost devoid o vegetation (Figure 15).
The of S of tl yria cannot be related previous decade (mainly cl drou data ght was never experie , the region is experie peak in 2008 (Figure 17). I %O his study!°. More detailed studi uster A ) was the severe drought (Darvishi, et al 2 nced in the half past century (Trigo et al, 2010 ncing consecutive droughts from 2004 (from November to April) to its refore, main factor of desertification ai to population changes and destructive human ac es indicate that the main factor of n n this yeal nd generation of dust masses in northwest of Iraq and east tivities like other regions umerous dust storms o! 012). Some believe suck . Based on the available r the annual precipitation in some regio f the average (Darvishi, et al, 2012). ns decreased to below 2(
The of S of tl yria cannot be related previous decade (mainly cl drou data ght was never experie , the region is experie peak in 2008 (Figure 17). I %O his study!°. More detailed studi uster A ) was the severe drought (Darvishi, et al 2 nced in the half past century (Trigo et al, 2010 ncing consecutive droughts from 2004 (from November to April) to its refore, main factor of desertification ai to population changes and destructive human ac es indicate that the main factor of n n this yeal nd generation of dust masses in northwest of Iraq and east tivities like other regions umerous dust storms o! 012). Some believe suck . Based on the available r the annual precipitation in some regio f the average (Darvishi, et al, 2012). ns decreased to below 2(
[he spatial extent of the regions affected by drought in the past decade in Syria (ACSAD"®, 2011) and Irag (IAU!’, 2009) deserves for consideration. In the two countries the areas under the influence of drought in the past decade (Figure 18) are considerably coincident with the devastated areas where converted into sources of dust in the north of Tigris and Euphrates Basins (Figure 15). Exploitation f groundwater resources also was increased following this drought event in the region. This was out 0 of the environmental tolerance in most of the areas and led to a considerable decline in surface and ground water resources.
[he spatial extent of the regions affected by drought in the past decade in Syria (ACSAD"®, 2011) and Irag (IAU!’, 2009) deserves for consideration. In the two countries the areas under the influence of drought in the past decade (Figure 18) are considerably coincident with the devastated areas where converted into sources of dust in the north of Tigris and Euphrates Basins (Figure 15). Exploitation f groundwater resources also was increased following this drought event in the region. This was out 0 of the environmental tolerance in most of the areas and led to a considerable decline in surface and ground water resources.
Figure 18. the areas under the influence of drought in Syria in the past decade (the upper figure) anc the areas under the influence of drought in 2008 and 2009 (the peak of drought) in Iraq (the lower figure).
Figure 18. the areas under the influence of drought in Syria in the past decade (the upper figure) anc the areas under the influence of drought in 2008 and 2009 (the peak of drought) in Iraq (the lower figure).
Figure 19. annual mean of moisture content anomalies in Tigris and Euphrates drainage basins '°(in millimeters). extreme utilization of groundwater resources. These circumstances, due to use of saline water, coulc lead to intensification of desertification and development of incipient dust sources'®,
Figure 19. annual mean of moisture content anomalies in Tigris and Euphrates drainage basins '°(in millimeters). extreme utilization of groundwater resources. These circumstances, due to use of saline water, coulc lead to intensification of desertification and development of incipient dust sources'®,
Figure 20. Reservoir constructions built in Tigris and Euphrates Rivers (Kibaroglu and Scheumann 2011) The natural factors of drought (climate fl played a major surrounding lan resou recen resou rces (hum rces (Figu come: t years, constru ds. A re 20) an factors) in the coun region (Kibaroglu and Kramer , 2011 r House al nd KH role in decrease of water though the natural fac ction of different sto emerged as an enviro uctuations) and tors have played rage infrastructu nmental and poli RP 2! 2007, KHRP, 2005). temperature change (climate changes?” flows in Tigris and Euphrates and degradation of thei the major role, but management of water tries of the basin might have deteriorated the situations. Ir res for restore and regulation of wate tical problem among the countries of the , Yalcinkaya, 2010, Ayboga, 2009, Philip, et al 2006, The
Figure 20. Reservoir constructions built in Tigris and Euphrates Rivers (Kibaroglu and Scheumann 2011) The natural factors of drought (climate fl played a major surrounding lan resou recen resou rces (hum rces (Figu come: t years, constru ds. A re 20) an factors) in the coun region (Kibaroglu and Kramer , 2011 r House al nd KH role in decrease of water though the natural fac ction of different sto emerged as an enviro uctuations) and tors have played rage infrastructu nmental and poli RP 2! 2007, KHRP, 2005). temperature change (climate changes?” flows in Tigris and Euphrates and degradation of thei the major role, but management of water tries of the basin might have deteriorated the situations. Ir res for restore and regulation of wate tical problem among the countries of the , Yalcinkaya, 2010, Ayboga, 2009, Philip, et al 2006, The
Figure 21. surface cover in dust storm sources in southeast of Iraq. This is coincident with southern half part of watershed of Tigris and Euphrates Rivers (Darvishi, et al 2012). Un human devastati raq. In fact, the ZO hal su resources are lal are transported i basins, tl f of the wate like the northern half southeastern plains of Iraq (Fi es can be considered as one of ne that attracted lots of popu pared with d rface water resources (Schn hey get ng activiti region and the rshed com gure 16). Hen ce, in pri mountainous areas of no lation (Jaradat, ry agric epf, 2003). T rgely saline (K agriculture. Mo the salin circum the grou Euphrates (Figure 22). na long distances from more salt progressively. This is mai es are pos ibaroglu their o reover, fresh groundwater tab Persian Gulf in one hand and groundwater resources are al e waters proceeds towards water tables of stances can be found in the studies of Al-Jiburi an nd water resources are considerably salty in south his is whi and Scheumann, rigins in 1 le most of 2011). After Turkey highla inly d itioned in tl ue to evapora so overused of for ag fresh water. d Al-Basrawi (2011). They indicated that tershed, a considerable quantity of population resides in mary evaluations unlike the northern half, f factors of desertificatio rthern Iraq was the ancient Fertile Crescent” 2002). Essential differen ulture of upstream is its depe n in the southeast of ce of cultivation in southern ndence upon ground and the ground and surface water the ground and surface flows nds into the plains and terminal tion and wastewater of he vicinity of saline waters of riculture. As a result, The consequence of these em hal f of watershed of Tigris and
Figure 21. surface cover in dust storm sources in southeast of Iraq. This is coincident with southern half part of watershed of Tigris and Euphrates Rivers (Darvishi, et al 2012). Un human devastati raq. In fact, the ZO hal su resources are lal are transported i basins, tl f of the wate like the northern half southeastern plains of Iraq (Fi es can be considered as one of ne that attracted lots of popu pared with d rface water resources (Schn hey get ng activiti region and the rshed com gure 16). Hen ce, in pri mountainous areas of no lation (Jaradat, ry agric epf, 2003). T rgely saline (K agriculture. Mo the salin circum the grou Euphrates (Figure 22). na long distances from more salt progressively. This is mai es are pos ibaroglu their o reover, fresh groundwater tab Persian Gulf in one hand and groundwater resources are al e waters proceeds towards water tables of stances can be found in the studies of Al-Jiburi an nd water resources are considerably salty in south his is whi and Scheumann, rigins in 1 le most of 2011). After Turkey highla inly d itioned in tl ue to evapora so overused of for ag fresh water. d Al-Basrawi (2011). They indicated that tershed, a considerable quantity of population resides in mary evaluations unlike the northern half, f factors of desertificatio rthern Iraq was the ancient Fertile Crescent” 2002). Essential differen ulture of upstream is its depe n in the southeast of ce of cultivation in southern ndence upon ground and the ground and surface water the ground and surface flows nds into the plains and terminal tion and wastewater of he vicinity of saline waters of riculture. As a result, The consequence of these em hal f of watershed of Tigris and
Figure 22. underground water saltiness rate in downer mesopetomia (Al-Jiburi and Al-Basrawi, 2011)
Figure 22. underground water saltiness rate in downer mesopetomia (Al-Jiburi and Al-Basrawi, 2011)
Figure 23. (the left figures) the illustration of the figures from left to right and from up to down are vegetation changes in center and parts of southern Iraq in war betwee n Iraq and Iran 1980-1988, the initial sanction of United Nations in 1999-2000, and severe sanctions in 2000-2003 and the years after the war between Iraq and United States of A merica (Operation I (the right) agricultural lands in three periods in beginning of sanctio (2003), years after war (2011) (Gibson, 20 raqi Freedon) in 2003 to 2011; ns (1991), Saddam dismissal 2).
Figure 23. (the left figures) the illustration of the figures from left to right and from up to down are vegetation changes in center and parts of southern Iraq in war betwee n Iraq and Iran 1980-1988, the initial sanction of United Nations in 1999-2000, and severe sanctions in 2000-2003 and the years after the war between Iraq and United States of A merica (Operation I (the right) agricultural lands in three periods in beginning of sanctio (2003), years after war (2011) (Gibson, 20 raqi Freedon) in 2003 to 2011; ns (1991), Saddam dismissal 2).
Figure 24. dams and water regulation structures in southeast of Iraq, located in upstream of Hor Al Hoveyzeh, Hor Al Hemmar, and Central Marshlands (the blue color in the image).
Figure 24. dams and water regulation structures in southeast of Iraq, located in upstream of Hor Al Hoveyzeh, Hor Al Hemmar, and Central Marshlands (the blue color in the image).
Figure 25 . Marshlands in southeast of Iraq (left picture) in 1973 and 2011 (IAU, 2012), remainec lands (dark green) and destructed lands (pale green). Historical stages in destruction of the marshlands of Mesopotamia (Fitzpatrick, 2004).
Figure 25 . Marshlands in southeast of Iraq (left picture) in 1973 and 2011 (IAU, 2012), remainec lands (dark green) and destructed lands (pale green). Historical stages in destruction of the marshlands of Mesopotamia (Fitzpatrick, 2004).
Figure 26. changes in marshlands of southeastern Iraq (Darvishi Bloorani, et al 2012).
Figure 26. changes in marshlands of southeastern Iraq (Darvishi Bloorani, et al 2012).
Wa ter for Hamoon Lake. tification studies, th of Hamoon”’ is loca ometers (about 5 % ra large part would be inundated (Be It originates from H direction in Afghanistan Farah and the Arashkan Rivers. and reach the water Region has a water body downstream as Hamoon Plain. It was under the influence of ification and an active source of nce, in most of dese in. The marshy land to 2500 square ki dust storm in past e researchers ek, 2008). He ted downstream of Sistan Basin (Figure 27). The plain is of the entire basin) and in high water years entire of the decades (Goudie and Middleton, 2006). paid more attention to this part of Sistan mand River provides a huge proportion of endookesh Hi ghlands and passes all its way in east-west body. Other major rivers of the water body are K hash, Jnii hwater resource. The main reason of this is washi Tes ts transfer through Shile Passage i dations of the rivers of the region, and water level changes of Hamoon, regardless of minor ke other water bodies and term ages, made these coasts, parti nte nCi lependent upon opulation, abo nsity in historical periods. Arc ent civilization had been form inal plains, salt content of H nto God e Zerreh cularly delta of ng of salts Swamp. 1 Helmand amoon Lake is very low and it is a via flooding flows of Hirmand and The freshwater resource, occasional River, fertile and high population haeological surveys in Hamoon Plain have indicated that an ed in a city entitled Bumt City about 5000 years ago and Hamoon Lake (UNEP, 2006). The present statistics also indicate that a large ut 400000 people who some are Afghan refugees, are inhabitants in a boundary yetween Iran, Afghanistan and Pakistan (Beek, 2008). It is noteworthy that majority of the
Wa ter for Hamoon Lake. tification studies, th of Hamoon”’ is loca ometers (about 5 % ra large part would be inundated (Be It originates from H direction in Afghanistan Farah and the Arashkan Rivers. and reach the water Region has a water body downstream as Hamoon Plain. It was under the influence of ification and an active source of nce, in most of dese in. The marshy land to 2500 square ki dust storm in past e researchers ek, 2008). He ted downstream of Sistan Basin (Figure 27). The plain is of the entire basin) and in high water years entire of the decades (Goudie and Middleton, 2006). paid more attention to this part of Sistan mand River provides a huge proportion of endookesh Hi ghlands and passes all its way in east-west body. Other major rivers of the water body are K hash, Jnii hwater resource. The main reason of this is washi Tes ts transfer through Shile Passage i dations of the rivers of the region, and water level changes of Hamoon, regardless of minor ke other water bodies and term ages, made these coasts, parti nte nCi lependent upon opulation, abo nsity in historical periods. Arc ent civilization had been form inal plains, salt content of H nto God e Zerreh cularly delta of ng of salts Swamp. 1 Helmand amoon Lake is very low and it is a via flooding flows of Hirmand and The freshwater resource, occasional River, fertile and high population haeological surveys in Hamoon Plain have indicated that an ed in a city entitled Bumt City about 5000 years ago and Hamoon Lake (UNEP, 2006). The present statistics also indicate that a large ut 400000 people who some are Afghan refugees, are inhabitants in a boundary yetween Iran, Afghanistan and Pakistan (Beek, 2008). It is noteworthy that majority of the
Figure 28. population intensity of Hamoon Plain (Izady, 2013b). Population within the border of Afghanistan is not depicted on this figure.
Figure 28. population intensity of Hamoon Plain (Izady, 2013b). Population within the border of Afghanistan is not depicted on this figure.
Figure 29. the general path of 120-day Wind and dust storms from dry plain od Hamoon (Khosravi, 2010).
Figure 29. the general path of 120-day Wind and dust storms from dry plain od Hamoon (Khosravi, 2010).
Figure 30. satellite image of Hamoon in 1976 and 2001 (Partow, 2003)
Figure 30. satellite image of Hamoon in 1976 and 2001 (Partow, 2003)
Figure 31. the extent of dried areas in Hamoon Puzak and Hamoon Baringak (in %) and number of days with dust storms in Hamoon Plain (Rashki, 2012) United States of America ( generation of internal and not much factor of and external wars important in building in use of these fl ain input ture in Indian Oceai Rashki, et al electricity and development of agriculture. Due in the country, they are now performing far fro reduction of reduction of surface flow al uctuations may be the amount of precipita into the rivers. Barlow et al. (2005 I sectors of ascendi ng and desc n and s reductio masses. in speci inconsis in the o events of water bodies in intensificatio ce of dust storm events (Figure 31). occulren helmin extent of 2006). Rashki f air Upon SOU from gly in Hamoon Lake w n in the extent of Nevertheless, their fying periods of tency may be the ther study the exte the region with c (2012) used satelli hanges in ex th west used as more tha Hai results are hat Rash nt of entire ubsequent ascend of of Asia parti ss would be very severe drough 985 to 2004 ca 1985-1988 and 2000-2004. te images moon in inconsiste increase and Fact t tent of Ha 2012) (Figure 27). These dai to UNEP, 2006). nd drying of surface flow ( tion in emphasize ending air masses. They believe that unu air from this water body a cularly on Afghanistan and Iran. ts in the region. Based on the last s eriods when the extent of Hamoon Between the years of 1988-1993 two p ms were initially constru incompetent management m their main func Hence, the importance o Hamoon Lake may be highlands of Af that each synoptic syste tion F hu neglig ghani m has two sual increase in air re concomitant with Obvious results of tudies, precipitation Lake was decreased and 1994-1999, the n average and up to average, respective and ground Statio ns in 0 nsification of desert condition and nt with findings of Delft hydrau nt of Hamoo inte decrease in exte ki (2012 ake has been studied. H moon La OW€VET, rder to exami n Lake. T have more focused on Puzak and Bar coincide ke is indicative of the promin n or weakening of desert condition downstream the basin and y (Delft hydraulics ne the role formation of du lics institute (200 he reason of th ingak, while of dust storm ent role of the ce
Figure 31. the extent of dried areas in Hamoon Puzak and Hamoon Baringak (in %) and number of days with dust storms in Hamoon Plain (Rashki, 2012) United States of America ( generation of internal and not much factor of and external wars important in building in use of these fl ain input ture in Indian Oceai Rashki, et al electricity and development of agriculture. Due in the country, they are now performing far fro reduction of reduction of surface flow al uctuations may be the amount of precipita into the rivers. Barlow et al. (2005 I sectors of ascendi ng and desc n and s reductio masses. in speci inconsis in the o events of water bodies in intensificatio ce of dust storm events (Figure 31). occulren helmin extent of 2006). Rashki f air Upon SOU from gly in Hamoon Lake w n in the extent of Nevertheless, their fying periods of tency may be the ther study the exte the region with c (2012) used satelli hanges in ex th west used as more tha Hai results are hat Rash nt of entire ubsequent ascend of of Asia parti ss would be very severe drough 985 to 2004 ca 1985-1988 and 2000-2004. te images moon in inconsiste increase and Fact t tent of Ha 2012) (Figure 27). These dai to UNEP, 2006). nd drying of surface flow ( tion in emphasize ending air masses. They believe that unu air from this water body a cularly on Afghanistan and Iran. ts in the region. Based on the last s eriods when the extent of Hamoon Between the years of 1988-1993 two p ms were initially constru incompetent management m their main func Hence, the importance o Hamoon Lake may be highlands of Af that each synoptic syste tion F hu neglig ghani m has two sual increase in air re concomitant with Obvious results of tudies, precipitation Lake was decreased and 1994-1999, the n average and up to average, respective and ground Statio ns in 0 nsification of desert condition and nt with findings of Delft hydrau nt of Hamoo inte decrease in exte ki (2012 ake has been studied. H moon La OW€VET, rder to exami n Lake. T have more focused on Puzak and Bar coincide ke is indicative of the promin n or weakening of desert condition downstream the basin and y (Delft hydraulics ne the role formation of du lics institute (200 he reason of th ingak, while of dust storm ent role of the ce
Figure 32. Number of days with dust storms (with visibility less than 2 km), recorded at Zabol Station in Hamoon Hirmand Delta (Rashki et al, 2012) The main cause of intensification in desert condition in the region is drought in Afghanistan, severe reduction in surface flow of Sistan Basin and drying of Hamoon Lake. However, the role of agricultural activities in destruction of cultivated lands and acceleration of soil erosion cannot be ignored. According to the information hardly available (due to security issues in the region), about 120000 hectares of lands in the region are now Cultivated. If the recent drought is continued and hydro-structures are reconstructed in Afghanistan, the cultivated lands may convert into desert regions and permanent sources of dust storms. Hence, based on the conducted studies, the best solution to cope with these conditions is that reduce cultivated lands to about 21000 hectares (Delft hydraulics, 2006). As it was mentioned, desertification and dust storm in Hamoon Plain is resulted from severe drought in Afqhanictan radiucthon af airfara flauz, drnzaingd af Wamnnonn JT ala and tha enrminding dalta Tha
Figure 32. Number of days with dust storms (with visibility less than 2 km), recorded at Zabol Station in Hamoon Hirmand Delta (Rashki et al, 2012) The main cause of intensification in desert condition in the region is drought in Afghanistan, severe reduction in surface flow of Sistan Basin and drying of Hamoon Lake. However, the role of agricultural activities in destruction of cultivated lands and acceleration of soil erosion cannot be ignored. According to the information hardly available (due to security issues in the region), about 120000 hectares of lands in the region are now Cultivated. If the recent drought is continued and hydro-structures are reconstructed in Afghanistan, the cultivated lands may convert into desert regions and permanent sources of dust storms. Hence, based on the conducted studies, the best solution to cope with these conditions is that reduce cultivated lands to about 21000 hectares (Delft hydraulics, 2006). As it was mentioned, desertification and dust storm in Hamoon Plain is resulted from severe drought in Afqhanictan radiucthon af airfara flauz, drnzaingd af Wamnnonn JT ala and tha enrminding dalta Tha
Although in different parts of Aral Sea the influence of desertification processes such as erosion and saltification require more examination, but same as Sistan Basin the most obvious result of the processes is observable in terminal part at Lake of Aral. In other words, majority of studies in relation to desertification in the basin were mainly focused upon drying of Aral Sea, erosion and destruction of surrounding deltas.
Although in different parts of Aral Sea the influence of desertification processes such as erosion and saltification require more examination, but same as Sistan Basin the most obvious result of the processes is observable in terminal part at Lake of Aral. In other words, majority of studies in relation to desertification in the basin were mainly focused upon drying of Aral Sea, erosion and destruction of surrounding deltas.
Figure 34. the process of drying at Aral Sea (UNEP and ENVSEC 2011)*° and the occurrence of dust storms as a result of desertification (Earth Observatory, 2010)?’
Figure 34. the process of drying at Aral Sea (UNEP and ENVSEC 2011)*° and the occurrence of dust storms as a result of desertification (Earth Observatory, 2010)?’
and on deltas. In other words, in Sistan Basin population concentration is low in upstream areas; this is because of different problems in Afghanistan as the origins of the rivers of the basin and the absence of required possibilities for development of human societies. Therefore, reduction of surface flow and drying of Hamoon cannot be attributed to human activities upstream. This is while in Aral Basin human societies are greatly concentrated in nearest locations relative to river flows. So, the principal reason for drying of Aral might be reduction of surface flows as a result of development of agricultural activities (human factor) in neighboring countries (Aladin, 2007). In order to revive decaying economy of Central A sian countries including Uzbekis Tajikistan, and others, the government of Soviet Union in 1960s made it mandatory that cotton must tan, Turkmenistan, be cultivated in some fertile lands (UN, 2011). Need for huge volume of water for continuous irrigation is one of the characteristics of this product. Hence, the government has decided to construct diversi considerable vo upon Amu Darya and Syr Darya Rivers are consumed for agricultu 2007). In 1950 to 1990, the area of ted increase, about 150 and 130 and recently w surrounding Am %, respectively. Uzbekistan are i and ENVSEC, 2 of the countries, desertification p reduction in wa Decay of Amu Darya and Syr Da considered as e appeared in the about 20, 25, and 28 %, ume of water (5 heat (Chatterjee, rocesses in Aral an nvironmental crisi near future (UN, agricultural was between 3.3 and 7.1 gallon per li u Darya and Syr Darya has experienced unpreceden t is noteworthy that some countries including ncreasingly dependent upon incomes from agricultu respectively, of gross domestic product are provided by these goods (UNEP 011). Although, the prosperity of agricultural activiti but reduction and pollution of surface flow are destructive consequences of the activities dependent upon irrigation. Both the reduction and polluti d the riparian areas of the flows downstream. Consequence of the ter flow of Aral Basin can easily be observed in drying out of tl rya by salinization and entrance of wastewater into the rivers are s in the region. The final consequence of these crises will be 2011). Based on researches (Spoor, 1998) the salinity ratio in tewater and the primary water used (the water entered into farms for irrigation) is inent huge constructio on canals to convey river flow towards the lands previously had dry condition (UNEP and ENVSEC, 2011). Karkum Canal is an em n that conveys a 00 million cubic meters) towards the previously dry lands in Turkmenistan. Approximately 90 % of the water conveyed by this canal and other constructions ral ac Tajiki tivities particularly cot tton the cultivated porti stan, Turkmenistan, es in on of ons and ral products. As in the countries the region saved economy surface flows exacerbate he terminal lake. ter along Amu Darya River. This salinity along with municipal
and on deltas. In other words, in Sistan Basin population concentration is low in upstream areas; this is because of different problems in Afghanistan as the origins of the rivers of the basin and the absence of required possibilities for development of human societies. Therefore, reduction of surface flow and drying of Hamoon cannot be attributed to human activities upstream. This is while in Aral Basin human societies are greatly concentrated in nearest locations relative to river flows. So, the principal reason for drying of Aral might be reduction of surface flows as a result of development of agricultural activities (human factor) in neighboring countries (Aladin, 2007). In order to revive decaying economy of Central A sian countries including Uzbekis Tajikistan, and others, the government of Soviet Union in 1960s made it mandatory that cotton must tan, Turkmenistan, be cultivated in some fertile lands (UN, 2011). Need for huge volume of water for continuous irrigation is one of the characteristics of this product. Hence, the government has decided to construct diversi considerable vo upon Amu Darya and Syr Darya Rivers are consumed for agricultu 2007). In 1950 to 1990, the area of ted increase, about 150 and 130 and recently w surrounding Am %, respectively. Uzbekistan are i and ENVSEC, 2 of the countries, desertification p reduction in wa Decay of Amu Darya and Syr Da considered as e appeared in the about 20, 25, and 28 %, ume of water (5 heat (Chatterjee, rocesses in Aral an nvironmental crisi near future (UN, agricultural was between 3.3 and 7.1 gallon per li u Darya and Syr Darya has experienced unpreceden t is noteworthy that some countries including ncreasingly dependent upon incomes from agricultu respectively, of gross domestic product are provided by these goods (UNEP 011). Although, the prosperity of agricultural activiti but reduction and pollution of surface flow are destructive consequences of the activities dependent upon irrigation. Both the reduction and polluti d the riparian areas of the flows downstream. Consequence of the ter flow of Aral Basin can easily be observed in drying out of tl rya by salinization and entrance of wastewater into the rivers are s in the region. The final consequence of these crises will be 2011). Based on researches (Spoor, 1998) the salinity ratio in tewater and the primary water used (the water entered into farms for irrigation) is inent huge constructio on canals to convey river flow towards the lands previously had dry condition (UNEP and ENVSEC, 2011). Karkum Canal is an em n that conveys a 00 million cubic meters) towards the previously dry lands in Turkmenistan. Approximately 90 % of the water conveyed by this canal and other constructions ral ac Tajiki tivities particularly cot tton the cultivated porti stan, Turkmenistan, es in on of ons and ral products. As in the countries the region saved economy surface flows exacerbate he terminal lake. ter along Amu Darya River. This salinity along with municipal
wastewater has such enormous destructive potenti dry areas (Spoor, 1998). Multiple use of agricultu extent of lands with high Amu Darya Basin (incre the lands irrigated by Syr hectares) (UNEP, 2005). reform ag. ands of the water body a dependence of the region the need for enormous vo Temperature change is an ral wastewater downstreai ty was increased about 57 % just illion hectares). i.e., the value was 79 % (i ts to rehabilitate Aral Lake a region. These works have obtained some achievements su FAS?8, 2003). Because of some far from ex vities, politi Aral Sea (Mic e region. As it ased f ricultural techni reclamation of northern Aral lume of ial salini rom 1.16 to 1.82 m a River, e rece in the I nd its coastal economy on Dary In th ques nt years there region agricu water to re other i Euphrates, increase in te snow melting. The increase makes a season to the early of warm season. the total flow discharged in surface flows in the deterioration of the effects of dryness when period. ffects th shift in This co was not altered in th early of warm pe mperature al maximu e two the wa m of Aral Basin S was not tural acti habilitate nfluencing factor in th e temp ndition i that may con were attemp 0 m flow of th vers, inter-al riod (Sulton, 2009). 1 ral distributi s obviously rec rn vert the reclaimed lands agai: has more devastating impacts in a decade, from 1990 to 20 The situation was more viol ncreased from 0.34 to 0.61 m factors, devastation of agricu pected. These factors are incl cal discords in the region, an klin, 2007). was mentioned about Tign of surface flows resulted region from middle of the orded both the rivers. Alth ual fluctuations indicate inc The result of this conditi on e nn ter is absent in the middle and the late of Figure 36 indicate tl dust storm generatio he areas affected by desertification influence of cultivation. As a result, principal factor o sources in Aral cou extreme exploitation Id be due to high population de of water resources and agricultu in Aral Sea Basin. f desertification and Majority of the areas of n (the yellow arrows in the figure) are coincident with dried portions of A ral Sea and also the coasts of the basin. These areas in long time didn’t have biolo gical potential under the formation of dust storm nsity. The consequence of this influence is ral lands. This, in turn, led to drying out of
wastewater has such enormous destructive potenti dry areas (Spoor, 1998). Multiple use of agricultu extent of lands with high Amu Darya Basin (incre the lands irrigated by Syr hectares) (UNEP, 2005). reform ag. ands of the water body a dependence of the region the need for enormous vo Temperature change is an ral wastewater downstreai ty was increased about 57 % just illion hectares). i.e., the value was 79 % (i ts to rehabilitate Aral Lake a region. These works have obtained some achievements su FAS?8, 2003). Because of some far from ex vities, politi Aral Sea (Mic e region. As it ased f ricultural techni reclamation of northern Aral lume of ial salini rom 1.16 to 1.82 m a River, e rece in the I nd its coastal economy on Dary In th ques nt years there region agricu water to re other i Euphrates, increase in te snow melting. The increase makes a season to the early of warm season. the total flow discharged in surface flows in the deterioration of the effects of dryness when period. ffects th shift in This co was not altered in th early of warm pe mperature al maximu e two the wa m of Aral Basin S was not tural acti habilitate nfluencing factor in th e temp ndition i that may con were attemp 0 m flow of th vers, inter-al riod (Sulton, 2009). 1 ral distributi s obviously rec rn vert the reclaimed lands agai: has more devastating impacts in a decade, from 1990 to 20 The situation was more viol ncreased from 0.34 to 0.61 m factors, devastation of agricu pected. These factors are incl cal discords in the region, an klin, 2007). was mentioned about Tign of surface flows resulted region from middle of the orded both the rivers. Alth ual fluctuations indicate inc The result of this conditi on e nn ter is absent in the middle and the late of Figure 36 indicate tl dust storm generatio he areas affected by desertification influence of cultivation. As a result, principal factor o sources in Aral cou extreme exploitation Id be due to high population de of water resources and agricultu in Aral Sea Basin. f desertification and Majority of the areas of n (the yellow arrows in the figure) are coincident with dried portions of A ral Sea and also the coasts of the basin. These areas in long time didn’t have biolo gical potential under the formation of dust storm nsity. The consequence of this influence is ral lands. This, in turn, led to drying out of
Figure 37. different states in an ecosystem (D’Odorico, 2013). a: stable and unstable, b: resiliency to its previous state (transient) factors of dust storm gen desertified areas al destruction of biologic H b and dese Hence, in are know version of an al uch situations i nce of the on time detection of desert bow rea from semidesert state into desert one m eans complete destruction t would be very difficult or impossible to eration and characteristics of the sources. Spatial-temporal properties of the re appeared as another important issue. In fact, recognition of the factors in resources is one of the essential elements for tackling this pheno owever, developing indices and systems for monitoring spatial an rlifing areas can oundaries. The importa when con area. In s menon. d temporal changes of desertified be considered as another necessary measure to check expansion o F desert ndaries expansion would be clear of that return to the previous con ditions. every ecosystem non-desert (with good vegetation cover) and desert (without vegetation) n as stable condition while semiarid conditions are unstable or bi-stable (Figure 37 a).
Figure 37. different states in an ecosystem (D’Odorico, 2013). a: stable and unstable, b: resiliency to its previous state (transient) factors of dust storm gen desertified areas al destruction of biologic H b and dese Hence, in are know version of an al uch situations i nce of the on time detection of desert bow rea from semidesert state into desert one m eans complete destruction t would be very difficult or impossible to eration and characteristics of the sources. Spatial-temporal properties of the re appeared as another important issue. In fact, recognition of the factors in resources is one of the essential elements for tackling this pheno owever, developing indices and systems for monitoring spatial an rlifing areas can oundaries. The importa when con area. In s menon. d temporal changes of desertified be considered as another necessary measure to check expansion o F desert ndaries expansion would be clear of that return to the previous con ditions. every ecosystem non-desert (with good vegetation cover) and desert (without vegetation) n as stable condition while semiarid conditions are unstable or bi-stable (Figure 37 a).
Figure 39. Correlation coefficient of precipitation and NDVI in Churu, Rajestan State and (B) the trenc of change in the region This may not be possible to determine the human or natural causes of desertification in a region just by relying on the correlation between two datasets of precipitation and vegetation. However, the results of the study indicate permanent des intervals to eli have initially been used to de other informati that changes in NDVI may be influenced by occasional variations in precipitation. This is while; the vegetation changes do not mean definite changes in climate, truction and desertification in the region*'. Rain- elimin ating the effects of tem from the coefficient between amount of vegetation and obviate this problem, Symeo tored in plants, is more competent than NDVI. A NDVI, but in NPP equation poral climatic fluctuations resulted from nakis and Drake (2004) believe that use equation 1) sum of the values of NDV minate the slig ON SOUICES. termine the regression equation are calc -use efficiency in of NPP*? though, N vegetation precipitation of a region. To dex is a method for indices. The index index, as useful and PP is derived from are calcu ulated thro ated in longer time ht fluctuations in datasets. It is noteworthy that, the values of NPP that ugh field surveys or
Figure 39. Correlation coefficient of precipitation and NDVI in Churu, Rajestan State and (B) the trenc of change in the region This may not be possible to determine the human or natural causes of desertification in a region just by relying on the correlation between two datasets of precipitation and vegetation. However, the results of the study indicate permanent des intervals to eli have initially been used to de other informati that changes in NDVI may be influenced by occasional variations in precipitation. This is while; the vegetation changes do not mean definite changes in climate, truction and desertification in the region*'. Rain- elimin ating the effects of tem from the coefficient between amount of vegetation and obviate this problem, Symeo tored in plants, is more competent than NDVI. A NDVI, but in NPP equation poral climatic fluctuations resulted from nakis and Drake (2004) believe that use equation 1) sum of the values of NDV minate the slig ON SOUICES. termine the regression equation are calc -use efficiency in of NPP*? though, N vegetation precipitation of a region. To dex is a method for indices. The index index, as useful and PP is derived from are calcu ulated thro ated in longer time ht fluctuations in datasets. It is noteworthy that, the values of NPP that ugh field surveys or
Figure 40. the amount of effective precipitation (dry matter in kilogram per hectare per year in millimeter) in central and south A frica in 1996 (Symeonakis and Drake, 2004). for this may be the slight growth of vegetation due to overwhelming evapotranspiration in such regions. Nevertheless, the values of this index in arid regions affected by desertification are less than non-desertified regions. Finally, though in this study just one map was drawn, but for better understanding of desertification trend in the region it seems necessary to calculate the index for several consecutive years and even for several decades. Doing so may have great ability for monitoring the trend of changes. Although, vegetation growth is somewhat representative of soil health and high productivity, but some plants like Chanar as halophyte plant adapted to desert areas cannot be a good criterion for biological health for an area (Collado, 2002). Hence, Symeonakis and Drake (2004) recommended other indices in addition to NDVI for monitoring of desert condition. They maintain that runoff coefficient (ratio of runoff flow to effective storm rainfall, i.e., the total rainfall that can produce surface flow) is one of the most competent indices to recognize destructed areas**. This is evident that destructed areas which lose their vegetation have more coefficient of surface flow relative to the surrounding regions. They also presented an additional relation to assess rate of soil erosion (equation 2).
Figure 40. the amount of effective precipitation (dry matter in kilogram per hectare per year in millimeter) in central and south A frica in 1996 (Symeonakis and Drake, 2004). for this may be the slight growth of vegetation due to overwhelming evapotranspiration in such regions. Nevertheless, the values of this index in arid regions affected by desertification are less than non-desertified regions. Finally, though in this study just one map was drawn, but for better understanding of desertification trend in the region it seems necessary to calculate the index for several consecutive years and even for several decades. Doing so may have great ability for monitoring the trend of changes. Although, vegetation growth is somewhat representative of soil health and high productivity, but some plants like Chanar as halophyte plant adapted to desert areas cannot be a good criterion for biological health for an area (Collado, 2002). Hence, Symeonakis and Drake (2004) recommended other indices in addition to NDVI for monitoring of desert condition. They maintain that runoff coefficient (ratio of runoff flow to effective storm rainfall, i.e., the total rainfall that can produce surface flow) is one of the most competent indices to recognize destructed areas**. This is evident that destructed areas which lose their vegetation have more coefficient of surface flow relative to the surrounding regions. They also presented an additional relation to assess rate of soil erosion (equation 2).
Figure 41. (A) the areas under the influence of desert condition based on surface runoff coefficient and (B) based on intensity of erosion (Symeonakis and Drake, 2004).
Figure 41. (A) the areas under the influence of desert condition based on surface runoff coefficient and (B) based on intensity of erosion (Symeonakis and Drake, 2004).
Figure 42. GSI equation used in northeast China (Xiao, et al 2006) Where, R, G, and B are Red, Green, and Blue bands of Landsat imager, respectively. In this relation the numerator is used to differentiate vegetation from barren areas. The difference of these two bands in the areas with dense vegetation cover is negligible, while for non-vegetated areas this has maximum values. On the other hand, the changes of denominator are related to diameter of grain sizes. As a result, using this index not only the quality of vegetation and its changes is revealed, bu soil texture and its changes over time can also be discerned. The output range of this equation is from minus zero to 0.2 or more. Water bodies and vegetation covers have minus values close to zero and desert areas have values close to 0.2 or more. By this way, it is possible to clearly determine the boundaries of desert and destructed areas (e.g., figure 42). One of the implications of the results is concentration of desert regions around the surface flows. It is likely that the destructed agricultural lands are dependent upon the river flows. Abdul Jabbar et al (2010) determined vegetation changes in marshlands of southeast Iraq. In this study, addition to using NDVI, they introduced Temporal Classification Comparison (TCC) as a competent index to distinguish vegetation changes, water bodies, and finally expansion in desert areas. They classified high spatial resolution images (such as Landsat) in different time periods to specify environmental changes, particularly in water bodies and vegetation. In figure 43, the stages
Figure 42. GSI equation used in northeast China (Xiao, et al 2006) Where, R, G, and B are Red, Green, and Blue bands of Landsat imager, respectively. In this relation the numerator is used to differentiate vegetation from barren areas. The difference of these two bands in the areas with dense vegetation cover is negligible, while for non-vegetated areas this has maximum values. On the other hand, the changes of denominator are related to diameter of grain sizes. As a result, using this index not only the quality of vegetation and its changes is revealed, bu soil texture and its changes over time can also be discerned. The output range of this equation is from minus zero to 0.2 or more. Water bodies and vegetation covers have minus values close to zero and desert areas have values close to 0.2 or more. By this way, it is possible to clearly determine the boundaries of desert and destructed areas (e.g., figure 42). One of the implications of the results is concentration of desert regions around the surface flows. It is likely that the destructed agricultural lands are dependent upon the river flows. Abdul Jabbar et al (2010) determined vegetation changes in marshlands of southeast Iraq. In this study, addition to using NDVI, they introduced Temporal Classification Comparison (TCC) as a competent index to distinguish vegetation changes, water bodies, and finally expansion in desert areas. They classified high spatial resolution images (such as Landsat) in different time periods to specify environmental changes, particularly in water bodies and vegetation. In figure 43, the stages
Figure 43. classification of surface vegetation covers in marshlands of southeastern Iraq (A bdul Jabbar, 2010) of degradation in marshlands of Iraq can be observed. This is while; the classification of images (1973) indicates considerable proportion of vegetation in marshland areas. In 1990, the water bodies and densely vegetation covers were replaced by clay soils and agricultural lands. In 2000, addition to more destruction of water bodies and dense vegetation covers, the desert areas (Sebkha) can clearly be observed in floodplains of previous decades.
Figure 43. classification of surface vegetation covers in marshlands of southeastern Iraq (A bdul Jabbar, 2010) of degradation in marshlands of Iraq can be observed. This is while; the classification of images (1973) indicates considerable proportion of vegetation in marshland areas. In 1990, the water bodies and densely vegetation covers were replaced by clay soils and agricultural lands. In 2000, addition to more destruction of water bodies and dense vegetation covers, the desert areas (Sebkha) can clearly be observed in floodplains of previous decades.
Figure 44. ten year changes of sand dunes in central Iraq (Fadhil, 2009) to specify the boundaries of the areas where either are co natural and human resources and to advise a planning for Despite of the capabilities of the indices, many of them rather to in biological resources is in final stages. However, the main pu recognition of vulnerable areas to take appropriate approaches in measure to happening of desertification, Sepehr et al. (2007) specif mple destructio n of biological resources. They attempted to determi of each factor. They classified different regions by a variety desertified areas, they suggested the areas vulnerable relative ‘fective. This weighting is based on the magnitude of their of in dicate deser' tely desertifi rpose of such studies is quick order to prevent degradation of rehabilitation. T ification are just able ed or destruction of aking a precautious fied most of the factors effective i ne the relative im dices. In ad n portance and weights dition to determining to thi S phenomen that is effective in desertification, e.g., soil texture, is considered as a layer. According to thi method, all the factors as layers are assigned weights, from 1 as the least effective to 2 as the most e influence in desertification (by expert opinion). Then, using geometric mean, the different layers were converted into one of the main indices, e.g., soil quality index (equation 5).
Figure 44. ten year changes of sand dunes in central Iraq (Fadhil, 2009) to specify the boundaries of the areas where either are co natural and human resources and to advise a planning for Despite of the capabilities of the indices, many of them rather to in biological resources is in final stages. However, the main pu recognition of vulnerable areas to take appropriate approaches in measure to happening of desertification, Sepehr et al. (2007) specif mple destructio n of biological resources. They attempted to determi of each factor. They classified different regions by a variety desertified areas, they suggested the areas vulnerable relative ‘fective. This weighting is based on the magnitude of their of in dicate deser' tely desertifi rpose of such studies is quick order to prevent degradation of rehabilitation. T ification are just able ed or destruction of aking a precautious fied most of the factors effective i ne the relative im dices. In ad n portance and weights dition to determining to thi S phenomen that is effective in desertification, e.g., soil texture, is considered as a layer. According to thi method, all the factors as layers are assigned weights, from 1 as the least effective to 2 as the most e influence in desertification (by expert opinion). Then, using geometric mean, the different layers were converted into one of the main indices, e.g., soil quality index (equation 5).
Figure 45. intensity of desertification in Fidoye-Garmosht Plain southwest of Iran (Sepehr, 2007)
Figure 45. intensity of desertification in Fidoye-Garmosht Plain southwest of Iran (Sepehr, 2007)
collaboration of research consortium of the Netherland managed by Delft Hydraulic research group (2006) made an effort to predict forthcoming condition related to changes in agricultural activities and its impacts on water resources of the region.
collaboration of research consortium of the Netherland managed by Delft Hydraulic research group (2006) made an effort to predict forthcoming condition related to changes in agricultural activities and its impacts on water resources of the region.
Figure 47. limitation in rehabilitation of marshland areas in southeast of Iraq (UNEP, 2010).
Figure 47. limitation in rehabilitation of marshland areas in southeast of Iraq (UNEP, 2010).
Figure 48. rehabilitated areas of marshland in southeast Iraq after revival operations.
Figure 48. rehabilitated areas of marshland in southeast Iraq after revival operations.
Related topics:
GeographyRemote SensingClimate ChangeClimatologyIranian StudiesEolian dustWest Asia
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