ارزيابي آسيب‌پذيري آلودگي آبخوان دشت سلماس با مدل دراستيك و سيستم اطلاعات جغرافيايي

Evaluation of Salmas Plain Aquifer Vulnerability to Pollution Using DRASTIC Model and GIS

در اين تحقيق آسيب ­پذيري آبخوان دشت سلماس در برابر آلودگي­ ها، با استفاده از مدل دراستيك و اﻃﻼﻋﺎت ﺟﻐﺮاﻓﯿﺎﯾﯽ ارزﯾﺎﺑﯽ ﺷﺪ. در ﻣﺪل دراﺳﺘﯿﮏ، ﻫﻔﺖ ﭘﺎراﻣﺘﺮ ﻫﯿﺪروژﺋﻮﻟﻮژﯾﮏ ﻣﺆﺛﺮ ﺑﺮ آﻟﻮدﮔﯽ آبﻫﺎي زﯾﺮزﻣﯿﻨﯽ ﻋﻤﻖ ﺳــﻄﺢ اﯾﺴــﺘﺎﺑﯽ، ﺗﻐﺬﯾﻪ ﺧﺎﻟﺺ آﺑﺨﻮان، ﻣﺤﯿﻂ آﺑﺨﻮان، ﺑﺎﻓﺖ ﺧﺎك، ﺗﻮﭘﻮﮔﺮاﻓﯽ، اﺛﺮ ﻣﻨﻄﻘﻪ ﻏﯿﺮاﺷــﺒﺎع و ﻫﺪاﯾﺖ ﻫﯿﺪروﻟﯿﮑﯽ ﺗﻠﻔﯿﻖ ﺷـﺪﻧﺪ . ﻧﻘﺸـﻪ ﭘﻬﻨﻪﺑﻨﺪي آﺳـ ﯿﺐﭘﺬﯾﺮي، ﺳـﻪ ﭘﻬﻨﻪ ﻋﻤﺪه آﺳﯿﺐ ﭘﺬﯾﺮي ﮐﻢ )ﺷﺎﺧﺺ آﺳﯿﺐﭘﺬﯾﺮي 64-100(، آﺳﯿﺐﭘﺬﯾﺮي ﻣﺘﻮﺳـﻂ )ﺷـﺎﺧﺺ آﺳـ ﯿﺐﭘﺬﯾﺮي100-140( و آﺳـ ﯿﺐﭘﺬﯾﺮي زﯾﺎد )ﺷﺎﺧﺺ آﺳﯿﺐﭘﺬﯾﺮي 140-183( را ﻧﺸﺎن داد. ﮔﺴﺘﺮش ﭘﻬﻨﻪﻫﺎ ﺑﺎ آﺳــﯿﺐﭘﺬﯾﺮي ﮐﻢ ﺣﺪود 13/55 درﺻــﺪ، آﺳــﯿﺐﭘﺬﯾﺮي ﻣﺘﻮﺳــﻂ ﺣﺪود 72/09 درﺻــﺪ و آﺳــﯿﺐﭘﺬﯾﺮي زﯾﺎد ﺣﺪود 14/36درﺻـﺪ ﺑﻪدﺳـﺖ آﻣﺪ. ﺑﺎ ﺗﺤﻠﯿﻞ ﺣﺴـﺎﺳ ﯿﺖ ﺑﻪ روشﻫﺎي ﺣﺬف ﭘﺎراﻣﺘﺮ و ﺗﮏ ﭘﺎراﻣﺘﺮي، ﻣﯿﺰان ﺗﺄﺛﯿﺮﮔﺬاري ﻫﺮ ﮐﺪام از ﭘﺎراﻣﺘﺮﻫﺎ در آﻟﻮدهﺳــﺎزي آﺑﺨﻮان ﻣﻮرد ارزﯾﺎﺑﯽ ﻗﺮارﮔﺮﻓﺖ. ﻧﺘﺎﯾﺞ ﻫﺮ دو ﺗﺤﻠﯿﻞ ﻧﺸــﺎن داد ﻋﻤﻖ ﺳــﻄﺢ اﯾﺴــﺘﺎﺑﯽ و ﻣﻨﻄﻘﻪ ﻏﯿﺮاﺷﺒﺎع ﻣﻬﻤﺘﺮﯾﻦ ﭘﺎراﻣﺘﺮﻫﺎي ﺗﺄﺛﯿﺮﮔﺬار ﺑﺮ ﺷﺎﺧﺺ آﺳﯿﺐﭘﺬﯾﺮي ﻣﺤﺪوده ﻣﻄﺎﻟﻌﺎﺗﯽ ﺳﻠﻤﺎس ﻣﯽﺑﺎﺷﻨﺪ.

In this research vulnerability of Salmas-plain aquifer to pollution was evaluated using the DRASTIC model and Geographic Information System. In DRASTIC model seven effective hydrogeological parameters on groundwater contamination; namely depth of water table, aquifer net recharge, aquifer media, soil texture, topography, impact of vadose zone and hydraulic conductivity were combined. Vulnerability zoning map showed three main zones of low groundwater vulnerability zone (risk index: 64-100), moderate groundwater vulnerability zone (risk index: 100-140) and high groundwater vulnerability zone (risk index: 140-183). Areas with low, moderate and high risk zones comprise 13.55%, 72.09% and 14.36% of the studied area, respectively. Two sensitivity analyses tests including the map removal and the single-parameter sensitivity analyses were carried out. Both of sensitivity analyses tests showed that the depth of water table and vadose zone parameters had the most significant impacts on the vulnerability indexes at the studied region.