بررسي نقش عوامل ادافيكي در پتانسيل بيابان‌زايي با كاربرد روش بهينه‌سازي چندمعياره و راه‌حل سازشي، مطالعه موردي: ارتفاعات حلقه دره، شهرستان اشتهارد، استان البرز

Assessing the role of edaphic factors on desertification potential using multicriteria optimization and compromise solution, case study: Halgh-e-Darreh highlands, Eshtehard County, Alborz Province

ﻓﺮاﯾﻨﺪ ﺑﯿﺎﺑﺎنزاﯾﯽ ﺑﺎ ﮐﺎﻫﺶ ﺗﻮان ﺗﻮﻟﯿﺪ ﺑﯿﻮﻟﻮژﯾﮏ، ﻣﻨﺠﺮ ﺑﻪ اﻧﻬﺪام اﮐﻮﺳﯿﺴﺘﻢﻫﺎي ﻃﺒﯿﻌﯽ ﻣﯽﺷﻮد. ﺑﻪﻣﻨﻈﻮر ﺑﺮرﺳﯽ ﭘﺘﺎﻧﺴﯿﻞ ﺧﻄﺮ ﺑﯿﺎﺑﺎنزاﯾﯽ در ﻣﺤﺪوده ﻣﺮاﺗﻊ ﻣﺸﺮف ﺑﻪ اﺷﺘﻬﺎرد )ارﺗﻔﺎﻋﺎت ﺣﻠﻘﻪ دره(، ﻧﺨﺴﺖ اﻗﺪام ﺑﻪ ﺗﻬﯿﻪ ﻧﻘﺸﻪ ﻃﺒﻘﺎت ﺷﯿﺐ، ﮐﺎرﺑﺮي اراﺿﯽ و زﻣﯿﻦﺷﻨﺎﺳﯽ ﺑﺎ ﻫﺪف اﯾﺠﺎد واﺣﺪﻫﺎي ﻫﻤﮕﻦ ﺷﺪ، ﺑﻪﻃﻮريﮐﻪ از ﻃﺮﯾﻖ روي ﻫﻢ ﻗﺮار دادن و ﺗﻘﺎﻃﻊ اﯾﻦ ﻧﻘﺸﻪ ﻫﺎ، ﻧﻘﺸﻪ واﺣﺪﻫﺎيﮐﺎري ﺣﺎﺻﻞ ﺷﺪ. در اﯾﻦ ﺗﺤﻘﯿﻖ، ﺳﻪ ﺷﺎﺧﺺ ﺣﺴﺎﺳﯿﺖﭘﺬﯾﺮي ﻧﺴﺒﺖ ﺑﻪ ﻓﺮﺳﺎﯾﺶ، ﺷﻮري و ﻧﻔﻮذﭘﺬﯾﺮي در ﻫﺮ ﯾﮏ از واﺣﺪﻫﺎي ﮐﺎري در ﻧﻈﺮ ﮔﺮﻓﺘﻪ ﺷﺪﻧﺪ ﮐﻪ در ﻧﻬﺎﯾﺖ ﻫﺮ ﯾﮏ ﺑﻪ ﺻﻮرت ﻧﻘﺸﻪ اي ﻃﺒﻘﻪ ﺑﻨﺪي ﺷﺪه اراﯾﻪ ﺷﺪﻧﺪ. در اﯾﻦ ﺗﺤﻘﯿﻖ، ﺑﻪﻣﻨﻈﻮر ﭘﻬﻨﻪ ﺑﻨﺪي ﻣﻨﻄﻘﻪ ﺗﺤﻘﯿﻖ از ﻧﻈﺮ ﺷﺎﺧﺺ ﺷﻮري و ﻧﯿﺰ ﻧﻔﻮذﭘﺬﯾﺮي ﺑﻪﺗﺮﺗﯿﺐ 185 و 179 ﻧﻤﻮﻧﻪ ﻃﯽ ﺳﺎلﻫﺎي 1396 و 1397 ﺑﺮداﺷﺖ ﺷﺪ. ﺳﭙﺲ، اﻗﺪام ﺑﻪ ﻣﺤﺎﺳﺒﻪ وزن ﺷﺎﺧﺺﻫﺎ و ﻧﯿﺰ ﻧﺴﺒﺖ ﺳﺎزﮔﺎري ﺑﺎ ﮐﺎرﺑﺮد روش ﻓﺮاﯾﻨﺪ ﺗﺤﻠﯿﻞ ﺳﻠﺴﻠﻪ ﻣﺮاﺗﺒﯽ )AHP( ﺷﺪ. ﻫﻤﭽﻨﯿﻦ، از روش ﺑﻬﯿﻨﻪﺳﺎزي ﭼﻨﺪﻣﻌﯿﺎره و راه ﺣﻞ ﺳﺎزﺷﯽ )VIKOR( ﺑﻪﻣﻨﻈﻮر ﺗﻌﯿﯿﻦ ﭘﺘﺎﻧﺴﯿﻞ ﺧﻄﺮ ﺑﯿﺎﺑﺎنزاﯾﯽ اﺳﺘﻔﺎده ﺷﺪ، ﺑﻪﻃﻮريﮐﻪ ﭘﺲ از ﻣﺤﺎﺳﺒﻪ ﻣﺎﺗﺮﯾﺲ اﺳﺘﺎﻧﺪاردﺷﺪه ﻣﻮزون، اوﻟﻮﯾﺖﺑﻨﺪي ﭘﺘﺎﻧﺴﯿﻞ ﺑﯿﺎﺑﺎنزاﯾﯽ واﺣﺪﻫﺎ ﻣﺒﺘﻨﯽ ﺑﺮ ﺷﺎﺧﺺ وﯾﮑﻮر اﻧﺠﺎم ﺷﺪ. داﻣﻨﻪ ﺗﻐﯿﯿﺮات ﺷﺎﺧﺺ وﯾﮑﻮر ﮔﺰﯾﻨﻪﻫﺎ ﻣﺒﺘﻨﯽ ﺑﺮ روش AHP-VIKOR از 0/443 ﺗﺎ 0/967 ﻣﺘﻐﯿﺮ اﺳﺖ. ﻧﺘﺎﯾﺞ ﺑﻪدﺳﺖ آﻣﺪه از روش ﺗﺤﻠﯿﻞ ﺳﻠﺴﻠﻪ ﻣﺮاﺗﺒﯽ )AHP( ﻧﺸﺎن داد ﮐﻪ از دﯾﺪﮔﺎه ﺧﺒﺮﮔﺎن، ﻣﻬﻤﺘﺮﯾﻦ ﻋﺎﻣﻞ ﻣﻮﺛﺮ در ﺑﯿﺎﺑﺎنزاﯾﯽ ، ﺷﻮري اﺳﺖ. ﺳﺎﯾﺮ ﻋﻮاﻣﻞ، از ﻗﺒﯿﻞ ﺣﺴﺎﺳﯿﺖ ﺑﻪ ﻓﺮﺳﺎﯾﺶ و ﻧﯿﺰ ﺿﺮﯾﺐ ﻧﻔﻮذﭘﺬﯾﺮي ﺑﻪ ﺗﺮﺗﯿﺐ در ردهﻫﺎي ﺑﻌﺪي اﻫﻤﯿﺖ ﻗﺮار دارﻧﺪ. ﻧﺘﺎﯾﺞ ﺣﺎﺻﻞ ﻧﺸﺎندﻫﻨﺪه اﻧﻄﺒﺎق ﺧﯿﻠﯽ زﯾﺎد ﻃﺒﻘﺎت ﭘﺘﺎﻧﺴﯿﻞ ﺧﻄﺮ ﺑﯿﺎﺑﺎنزاﯾﯽ ﺣﺎﺻﻞ از ﻣﺪل AHP-VIKOR ﺑﺎ ﻃﺒﻘﺎت ﻣﺮﺑﻮﻃﻪ در ﻧﻘﺸﻪ ﺷﺎﻫﺪ ﺑﻮده، ﺑﻪﻃﻮريﮐﻪ درﺻﺪ اﻧﻄﺒﺎق و ﻧﯿﺰ ﻋﺪم اﻧﻄﺒﺎق ﻃﺒﻘﺎت ﭘﺘﺎﻧﺴﯿﻞ ﺧﻄﺮ ﺑﯿﺎﺑﺎنزاﯾﯽ ﻣﺤﺎﺳﺒﺎﺗﯽ ﺑﺎ ﻧﻘﺸﻪ ﺷﺎﻫﺪ ﺑﻪﺗﺮﺗﯿﺐ 92/91 و 7/09 درﺻﺪ اﺳﺖ. ﺑﺮ اﯾﻦ اﺳﺎس، ﻣﻨﻄﻘﻪ ﺗﺤﻘﯿﻖ داراي ﺳﻪ ﻃﺒﻘﻪ ﭘﺘﺎﻧﺴﯿﻞ ﯾﺎ ﺷﺪت ﺧﻄﺮ ﺑﯿﺎﺑﺎن-زاﯾﯽ اﺳﺖ. ﺑﻪ ﻃﻮريﮐﻪ 169/39 ﻫﮑﺘﺎر )0/51 درﺻﺪ( از ﻣﻨﻄﻘﻪ داراي ﭘﺘﺎﻧﺴﯿﻞ ﻣﺘﻮﺳﻂ، 2336/56 ﻫﮑﺘﺎر )7/06 درﺻﺪ( داراي ﭘﺘﺎﻧﺴﯿﻞ زﯾﺎد و 30583/25 ﻫﮑﺘﺎر )92/43 درﺻﺪ( داراي ﭘﺘﺎﻧﺴﯿﻞ ﺧﯿﻠﯽ زﯾﺎد اﺳﺖ.

The desertification process, by reducing the biological production potential, leads to the destruction of ecosystems. In this research, to assess the role of edaphic factors on desertification in rangelands surrounding Eshtehard, Halgh-e-Darreh highlands, first, the map of units was created by crossing maps of slope classes, land uses, and geology using ArcGIS 10.3 software. Three indices of erodibility, salinity and permeability for each land unit were considered and classified. 185 and 179 samples were taken during 2018 and 2019 for indices of salinity and permeability for zoning of the study area, respectively. Then, weights of indices and consistency ratio were calculated by the AHP method. Method of multicriteria optimization and compromise solution, VIKOR method was used to prioritize the alternatives. After calculating the weighted normalized values, priority was given to desertification potential of the units. Also, the results of AHP showed that from the experts' point of view, salinity is the most important factor in desertification. Other factors such as susceptibility to erosion and permeability coefficient are in the next rank order, respectively. The AHP-VIKOR model has very high degree of adaptation to the corresponding classes in the control map. The percentage of compliance and non-compliance of the classes of the potential of desertification risk were 92.91% and 7.09%, respectively. The range of changes of Vikor index based on AHP-VIKOR method varies from 0.443 to 0.967. Accordingly, the study area has three classes of potential or severity of desertification areally 0.5% moderate, 7.06% high and 92.43% very high class respectively.