shima nikoo; Hossein Azarnivand; Gholam Reza Zehtabiyan; Hasan Ahmadi; Mohammad Ali Zare Chahouki
Abstract
Combating desertification which is a serious threat for the environment and human welfare requires understanding complex issues of this phenomenon using evaluation, awareness of severity of it's processes and determination of it's factors. So here, after recognizing the characteristics of the region ...
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Combating desertification which is a serious threat for the environment and human welfare requires understanding complex issues of this phenomenon using evaluation, awareness of severity of it's processes and determination of it's factors. So here, after recognizing the characteristics of the region showing existence desertification, we assess its current status with emphasis on climate, water, geology-geomorphology, soil and wind erosion as the most criteria of desertification. According to more consensus on regional model or flexible model to modify, Iranian Model for Desertification Potential Assessment (IMDPA) ,which is calibrated to use in arid area of Iran, was chosen. At first the rainfall seasonality indicator was added to the model as a special climate character. Then primary assessment of desertification was done. At last according to the result of primary assessment, the area environmental conditions and revealed issues during assessment the model was modified, final assessment and mapping of desertification were done. At last according to the result of primary assessment, the area environmental conditions and revealed issues during assessment the model was modified, final assessment and mapping of desertification were done. Based on the results desertification intensity in 33/94% and 66/06% of the area are severe and moderate respectively. Also the major factors affecting desertification across Damghan region are climate, salinization of water and soil resources, improper land use, over exploitation of underground water, over grazing and improper irrigation method.
Leila Bakhshandehmehr; Saeid Soltani; Adel Sepehr
Abstract
According to the UNCCD definition, “Desertification” is land degradation in arid, semi-aridand dry sub-humid areas resulting from various factors, including climatic variations andhuman activities. It has been recognized as a major economic, social, and environmentalproblem in many countries ...
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According to the UNCCD definition, “Desertification” is land degradation in arid, semi-aridand dry sub-humid areas resulting from various factors, including climatic variations andhuman activities. It has been recognized as a major economic, social, and environmentalproblem in many countries of the world. The MEDALUS methodology is a practical approachto assess the present status of desertification and evaluate the desertification risk. In this study,a regional model has been developed to desertification assessment and mapping in the SEGZIplain (Eastern Isfahan) based on the MEDALUS methodology. At first step, seven criteriaincluding climate, soil, vegetation cover, ground water, water erosion, wind erosion and policyand management were recognized according to the local condition. Each criterion includedseveral indicators accounting as factor quality determination. These indicators quantified basedon their influences on desertification process. For each indicator a score ranging from 100 to200 were assigned and desertification weighting was finally extracted. The weight of eachfactor and the weight of desertification status was calculated by geometric mean. Ultimately,desertification status was classified in four levels including low, moderate, severe and highsevere. At last the maps of these results was produced by geographical information system.Results showed that 2% of the study area was classified as moderate class, 35% classified assevere and 63% involved high severe class. Climate, policy and management are the mostimportant factors have led to desertification process in this region.
