Fatemeh Azariyan; Sara Valizadeh; Pouyan Dehghan; Hassan Khosravi
Abstract
Iran is mostly consisted of arid and semi-arid areas. Rudab region, Sabzevar, is indicative of an areaexposed to and affected by the risk of desertification. This study accordingly is aimed at assessingthe risk of desertification using ESAs model, through mapping the risk of desertification. Initially,work ...
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Iran is mostly consisted of arid and semi-arid areas. Rudab region, Sabzevar, is indicative of an areaexposed to and affected by the risk of desertification. This study accordingly is aimed at assessingthe risk of desertification using ESAs model, through mapping the risk of desertification. Initially,work units’ map was prepared based on which relevant indicators were valued. Then, relevantindices were prepared based on ESAs model using GIS. Finally, ESAI index was calculated foreach work unit. After mapping the risk of desertification, desertification damages were evaluated. Itwas found out that the risk of desertification in Rudab can be classified at three classes i.e. class I,II, and III; and subclass III1 covered the biggest surface of the study area i.e. 44.48%. Based ondesertification damage map, Rudab region is divided into five classes so that class III covering35.20 percent of the area is the biggest area. Active sandy dune faces are prone to the highest risk ofdesertification since they entail significant risk factors and need to be paid due attention for desertgreening programs.
s.h Parvari Asl1; ahmad Pahlavanravi; ali reza Moghaddam Nia
Volume 63, Issue 2 , September 2010, , Pages 149-16
Abstract
Desertification is the consequence of series of processes in which climate change and human activities are more important factors than others. Arid and semi-arid areas have occupied most parts of Iran. Sistan region is one of arid areas of Iran where wind erosion is an important factor of land degradation ...
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Desertification is the consequence of series of processes in which climate change and human activities are more important factors than others. Arid and semi-arid areas have occupied most parts of Iran. Sistan region is one of arid areas of Iran where wind erosion is an important factor of land degradation and soil deterioration. For classification of desertification intensity, several methods have been proposed so far. ESAs Model is on of the best and recent methodologies introduced by the European Commission in 1999 and evaluated by most of European as well as Middle Eastern countries. ESAs has more advantageous than other methods because of its accuracy, particular weighing of layers, use of geographical information systems in overlaying of maps, use of geometric mean over arithmetic one or sum in computing indices and final desertification map. The method was chosen to monitor desertification in the study area. The factors which affect on desertification were evaluated based on the related tables. According to the conditions of the study area, it was found that four factors including vegetation cover, soil, climate and land use management are the most important desertification factors. The results showed that climate play vital role in land degradation and desertification. Based on the results of it is found that the study area has critical conditions. It includes high critical (C3), moderate critical (C2) and low critical (C1) classes of desertification which cover 68%, less than 1% and 31% of the region, respectively.
