پهنه‌بندي آسيب‌پذيري آبخوان دشت‌ آبرفتي اردبيل با استفاده از تلفيق سامانه اطلاعات جغرافيايي و مدل دراستيك

Ardabil Alluvial Plain Aquifer Vulnerability Zoning Using a Combination of GIS and DRASTIC Method

زﻣﯿﻨﻪ و ﻫﺪف: ﻣﻨﺎﺑﻊ آب زﯾﺮزﻣﯿﻨﯽ دوﻣﯿﻦ ﻣﻨﺒﻊ آب ﺷﯿﺮﯾﻦ ﻣﻮﺟﻮد در ﺟﻬﺎن اﺳﺖ و ﺣﺪود ﯾﮏ ﺳﻮم ﺟﻤﻌﯿﺖ ﺟﻬﺎن واﺑﺴﺘﻪ ﺑﻪ آن ﻣﯽﺑﺎﺷﻨﺪ. اﯾﻦ آبﻫﺎ ﮐﻪ ﺗﻮﺳﻂ ﭼﺎهﻫﺎ، ﻗﻨﻮات و ﭼﺸﻤﻪﻫﺎ ﻗﺎﺑﻞ اﺳﺘﺤﺼﺎل ﻣﯽﺑﺎﺷﻨﺪ در ﻣﺼﺎرف ﻣﺨﺘﻠﻒ ﻣﻮرد اﺳﺘﻔﺎده ﮔﺮﻓﺘﻪ و در ﻋﻮض ﺣﺠﻢ زﯾﺎدي از ﭘﺴﺎب ﺧﺎﻧﮕﯽ، ﺻﻨﻌﺘﯽ و ﮐﺸﺎورزي وارد آﺑﺨﻮانﻫﺎ ﻣﯽﺷﻮد. ﻫﺪف اﯾﻦ ﺗﺤﻘﯿﻖ ارزﯾﺎﺑﯽ آﺳﯿﺐﭘﺬﯾﺮي آﺑﺨﻮان آﺑﺮﻓﺘﯽ دﺷﺖ اردﺑﯿﻞ ﺑﺮاي ﻣﺪﯾﺮﯾﺖ ﮐﺎرﺑﺮي اراﺿﯽ، ﻧﺤﻮه ﭘﺎﯾﺶ ﮐﯿﻔﯽ ﻣﻨﺎﺑﻊ آب زﯾﺮزﻣﯿﻨﯽ و ﺟﻠﻮﮔﯿﺮي از آﻟﻮدﮔﯽﻫﺎي آﺗﯽ آن ﻣﯽ ﺑﺎﺷﺪ. روش ﺑﺮرﺳﯽ: در اﯾﻦ ﺗﺤﻘﯿﻖ ﺑﺎ ﻫﺪف ﭘﻬﻨﻪﺑﻨﺪي آﺳﯿﺐﭘﺬﯾﺮي دﺷﺖ اردﺑﯿﻞ از ﻣﺪل دراﺳﺘﯿﮏ و ﺳﯿﺴﺘﻢ اﻃﻼﻋﺎت ﺟﻐﺮاﻓﯿﺎﯾﯽ اﺳﺘﻔﺎده ﺷﺪه و ﭘﺮدازش و ﺗﺠﺰﯾﻪ و ﺗﺤﻠﯿﻞ ﮐﯿﻔﯽ آﺑﺨﻮان ﺑﻪ ﮐﻤﮏ آﻧﻬﺎ اﻧﺠﺎم ﺷﺪه اﺳﺖ. ﻫﻤﭽﻨﯿﻦ ﺑﺎ اﺳﺘﻔﺎده از ﻧﺘﺎﯾﺞ ﻣﻮﺟﻮد ﺳﻨﺠﺶ ﻧﯿﺘﺮات در ﻣﻨﺎﺑﻊ آب زﯾﺮ زﻣﯿﻨﯽ ﻣﻨﻄﻘﻪ، ﻣﺪل دراﺳﺘﯿﮏ ﺑﺮاي دﺷﺖ اردﺑﯿﻞ واﺳﻨﺠﯽ ﺷﺪه اﺳﺖ. ﯾﺎﻓﺘﻪ ﻫﺎ: ﻧﺘﺎﯾﺞ ﺣﺎﺻﻞ از ﻣﺪل دراﺳﺘﯿﮏ ﻧﺸﺎن ﻣﯽدﻫﺪ ﮐﻪ آﺳﯿﺐﭘﺬﯾﺮي آﺑﺨﻮان دﺷﺖ اردﺑﯿﻞ ﺑﯿﺶﺗﺮ در ﮔﺮوه آﺳﯿﺐﭘﺬﯾﺮي ﻣﺘﻮﺳﻂ ﻣﯽﺑﺎﺷﺪ. ﻃﺒﻖ ﯾﺎﻓﺘﻪﻫﺎي اﯾﻦ ﺗﺤﻘﯿﻖ آﺳﯿﺐﭘﺬﯾﺮي ﻣﺘﻮﺳﻂ 39/3 درﺻﺪ، آﺳﯿﺐﭘﺬﯾﺮي ﮐﻢ 32/4 درﺻﺪ و آﺳﯿﺐﭘﺬﯾﺮي زﯾﺎد 21/1 درﺻﺪ، آﺳﯿﺐﭘﺬﯾﺮي ﺧﯿﻠﯽ ﮐﻢ 6 درﺻﺪ و آﺳﯿﺐﭘﺬﯾﺮي ﺧﯿﻠﯽ زﯾﺎد 1/1درﺻﺪ ﺑﻪ ﺗﺮﺗﯿﺐ ﺑﯿﺶﺗﺮﯾﻦ ﺳﻬﻢ از ﻣﺴﺎﺣﺖ دﺷﺖ را ﺑﻪ ﺧﻮد اﺧﺘﺼﺎص داده اﺳﺖ. ﺑﺤﺚ و ﻧﺘﯿﺠﻪ ﮔﯿﺮي: ﺑﺮ ﭘﺎﯾﻪ ﻧﺘﺎﯾﺞ ﺣﺎﺻﻞ از ﻣﺪلﺳﺎزي، آﺳﯿﺐ ﭘﺬﯾﺮي آﺑﺨﻮان دﺷﺖ اردﺑﯿﻞ ﺗﻘﺮﯾﺒﺎ در ﻧﯿﻤﻪﺷﺮﻗﯽ در ﮔﺮوه آﺳﯿﺐ ﭘﺬﯾﺮي ﮐﻢ و ﻧﯿﻤﻪ ﻏﺮﺑﯽ در ﮔﺮوه آﺳﯿﺐﭘﺬﯾﺮي زﯾﺎد ﻗﺮار ﻣﯽﮔﯿﺮد. ﻧﺘﺎﯾﺞ اﯾﻦ ﺗﺤﻘﯿﻖ ﻧﺸﺎن ﻣﯽدﻫﺪ ﮐﻪ ﭘﺘﺎﻧﺴﯿﻞ و ﻣﯿﺰان آﻟﻮدﮔﯽ آﺑﺨﻮان دﺷﺖ اردﺑﯿﻞ ﺑﺎﻻ ﻣﯽﺑﺎﺷﺪ. ﻟﺬا ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ اﻫﻤﯿﺖ ﻣﻨﺎﺑﻊ آب زﯾﺮزﻣﯿﻨﯽ ﻣﻨﻄﻘﻪ ﮐﻪ ﺑﺮاي اﻫﺪاف ﻣﺨﺘﻠﻒ ﺑﮑﺎر ﻣﯽرود، ﺣﻔﺎﻇﺖ اﯾﻦ ﻣﻨﺎﻃﻖ ﺑﻪ ﻣﻨﻈﻮر ﺟﻠﻮﮔﯿﺮي از آﻟﻮدﮔﯽ و ﺪﯾﺮﯾﺖ ﺑﻬﯿﻨﻪ ﻣﻨﺎﺑﻊ آب ﺿﺮوري اﺳﺖ.

Background and Objective: Groundwater resources are the second largest fresh water resources in the world and almost one third of the world population depend on these resources. These resources that are accessible through wells, canals and springs are utilized for different uses and in return they receive ample amount of domestic, industrial and agricultural waste waters. Assessment of aquifer vulnerability is very useful in land uses management and development, groundwater quality monitoring and prevention of water resources pollution. Method: In current study, DRASTIC model in conjunction with GIS is used for zoning Ardabil plain vulnerability and aquifer quality data processing and analysis is performed accordingly by these tools. It also uses the measurement results of nitrate in groundwater, DRASTIC model is calibrated to the Ardabil plain. Findings: The results of the drastic model show that the vulnerability of the Ardabil plain aquifer is more in the moderate vulnerability group. According to the findings of this study, moderate vulnerability is 39.3%, low vulnerability is 32.4% and high vulnerability is 21.1%, very low vulnerability is 6% and very high vulnerability is 1.1%, respectively. Discussion and Conclusion: The level of contaminations of Ardabil aquifer was observed to be high and the result of this research revealed that its potential to be polluted is high. Therefore, given the importance of the groundwater resources in the region, it is necessary to establish a management plan to optimize the usage of this valuable resource.