تحليل آلودگي آب زيرزميني با استفاده از رويكرد رتبه‌بندي شبيه به حل ايده‌ال فازي (مطالعه موردي: دشت زنجان)

Groundwater Contaminantion Analysis Using Fuzzy-Topsis, Case Study: ZANJAN Plain

زﻣﯿﻨﻪ و ﻫﺪف: ارزﯾﺎﺑﯽ ﮐﯿﻔﯿﺖ آب در دﺳﺘﺮس ﺑﻪ ﺧﺼﻮص ﺟﻬﺖ ﺗﺄﻣﯿﻦ ﻧﯿﺎزﻫﺎي ﺷﺮب از اﻫﻤﯿﺖ ﺑﺎﻻﯾﯽ ﺑﺮﺧﻮردار ﻣﯽﺑﺎﺷﺪ. ﻟﺬا ﺗﻬﯿﻪ و ﺗﺪوﯾﻦ روﯾﮑﺮدي ﮐﻪ ﺑﺘﻮاﻧﺪ ﺑﺎ دﻗﺖ ﺑﺎﻻﺗﺮ و ﺑﺎ در ﻧﻈﺮ ﮔﺮﻓﺘﻦ ﻋﺪم دﻗﺖﻫﺎي ﻧﺎﺷﯽ از ﺧﻄﺎﻫﺎي اﺑﺰاري و اﻧﺪازهﮔﯿﺮي، ارزﯾﺎﺑﯽ ﻣﻨﺎﺳﺐﺗﺮي را اراﯾﻪ دﻫﺪ ﻣﻬﻢ و ﻗﺎﺑﻞ ﺗﻮﺟﻪ اﺳﺖ. ﻫﺪف از اﯾﻦ ﻣﻄﺎﻟﻌﻪ ارزﯾﺎﺑﯽ ﮐﯿﻔﯿﺖ آب زﯾﺮزﻣﯿﻨﯽ دﺷﺖ زﻧﺠﺎن ﺑﺮ ﭘﺎﯾﻪ روش ﺷﺒﯿﻪ ﺑﻪ ﺣﻞ اﯾﺪهآل ﻓﺎزي اﺳﺖ. روش ﺑﺮرﺳﯽ: ﺟﻬﺖ دﺳﺖﯾﺎﺑﯽ ﺑﻪ اﯾﻦ ﻫﺪف، از اﻃﻼﻋﺎت 57 و 59 ﻧﻤﻮﻧﻪ از آﺑﺨﻮان ﺑﻪ ﺗﺮﺗﯿﺐ در دو ﻓﺼﻞ ﺧﺸﮏ و ﺗﺮ ﮐﻪ در ﻫﺮ ﻧﻤﻮﻧﻪ 28 ﭘﺎراﻣﺘﺮ ﮐﯿﻔﯽ ﻣﻮرد آﻧﺎﻟﯿﺰ ﻗﺮار ﮔﺮﻓﺘﻪ اﺳﺖ، اﺳﺘﻔﺎده ﮔﺮدﯾﺪ. ﺑﺎ ﺗﻌﯿﯿﻦ وزن ﻫﺮ ﯾﮏ از ﭘﺎراﻣﺘﺮﻫﺎي ﮐﯿﻔﯽ در ﻣﺤﯿﻂ ﻓﺎزي ﺑﺮ اﺳﺎس ﻧﻈﺮات اﻓﺮادﺧﺒﺮه در اﯾﻦ زﻣﯿﻨﻪ و ﺗﻌﯿﯿﻦ ﻣﺎﺗﺮﯾﺲ ﺗﺼﻤﯿﻢ ﻓﺎزي ﺑﺮ ﻣﺒﻨﺎي اﺳﺘﺎﻧﺪاردﻫﺎي ﮐﯿﻔﯽ ﺷﺮب، ﺿﺮﯾﺐ ﻧﺰدﯾﮑﯽ ﻧﺴﺒﯽ ﻫﺮ ﯾﮏ از ﻧﻤﻮﻧﻪﻫﺎ ﺗﻌﯿﯿﻦ و ﺑﺮ اﺳﺎس آن رﺗﺒﻪ آﻟﻮدﮔﯽ ﻫﺮ ﻧﻤﻮﻧﻪ ﻣﻮرد ﻣﺤﺎﺳﺒﻪ ﻗﺮار ﮔﺮﻓﺖ. ﯾﺎﻓﺘﻪﻫﺎ: ﻧﺘﺎﯾﺞ ﻧﺸﺎن ﻣﯽدﻫﺪ ﮐﻪ ﻧﻘﺎط آﻟﻮدهﺗﺮ ﻋﻤﺪﺗﺎً در ﻣﺮﮐﺰ و ﺷﻤﺎل ﻏﺮﺑﯽ دﺷﺖ ﻣﺘﻤﺮﮐﺰ ﺑﻮده و اﯾﻦ اﻣﺮ ﺑﺎ ﻣﻮﻗﻌﯿﺖ ﻣﺮاﮐﺰ ﺻﻨﻌﺘﯽ )ﻣﺎﻧﻨﺪ ﻣﺠﺘﻤﻊﻫﺎي ﺳﺮب و روي( و ﺧﺼﻮﺻﯿﺎت ﻫﯿﺪروژﺋﻮﻟﻮژﯾﮑﯽ آﺑﺨﻮان ﻫﻤﺎﻫﻨﮕﯽ ﮐﺎﻣﻞ دارد. ﺟﻬﺖ ارزﯾﺎﺑﯽ ﻣﯿﺰان دﻗﺖ رﺗﺒﻪﺑﻨﺪي اﻧﺠﺎم ﺷﺪه، ﻧﺘﺎﯾﺞ روش ﭘﯿﺸﻨﻬﺎدي ﺑﺎ ﺣﺎﻟﺖ ﻗﻄﻌﯽ روش ﺷﺒﯿﻪ ﺑﻪ ﺣﻞ اﯾﺪهال ﻣﻮرد ﻣﻘﺎﯾﺴﻪ ﻗﺮار ﮔﺮﻓﺖ. ﺑﺮرﺳﯽ ﭘﺎراﻣﺘﺮﻫﺎي ﮐﯿﻔﯽ ﻣﺮﺗﺒﻂ ﺑﻪ رﺗﺒﻪ 1 )ﮐﻢ ﺗﺮﯾﻦ ﻣﯿﺰان آﻟﻮدﮔﯽ(، ﻧﺸﺎندﻫﻨﺪه اﯾﻦ اﺳﺖ ﮐﻪ اﻏﻠﺐ ﭘﺎراﻣﺘﺮﻫﺎ در اﯾﻦ رﺗﺒﻪ ﮐﻪ ﻣﯽﺑﺎﯾﺴﺖ ﺑﯿﺎنﮔﺮ ﮐﻢﺗﺮﯾﻦ ﻣﯿﺰان آﻟﻮدﮔﯽ ﺑﺎﺷﻨﺪ، در روش ﻗﻄﻌﯽ ﻧﺴﺒﺖ ﺑﻪ روش ﻓﺎزي داراي ﻣﻘﺎدﯾﺮ ﺑﺎﻻﯾﯽ ﻣﯽﺑﺎﺷﻨﺪ )ﺑﻪ ﻋﻨﻮان ﻧﻤﻮﻧﻪ ﻣﻘﺪار ﭘﺎراﻣﺘﺮ آرﺳﻨﯿﮏ واﻗﻊ در رﺗﺒﻪ 1 روش ﻗﻄﻌﯽ و ﻓﺎزي ﺑﻪ ﺗﺮﺗﯿﺐ ﺑﺮاﺑﺮ ﺑﺎ 0/4 و 0 ﻣﯿﮑﺮوﮔﺮم در ﻟﯿﺘﺮ ﻣﯽﺑﺎﺷﺪ( و اﯾﻦ اﻣﺮ در ﺧﺼﻮص رﺗﺒﻪ 59 )ﺑﯿﺶﺗﺮﯾﻦ ﻣﯿﺰان آﻟﻮدﮔﯽ( ﻧﯿﺰ ﺑﻪ ﺻﻮرت ﻋﮑﺲ ﺗﮑﺮارﺷﺪه اﺳﺖ ﮐﻪ ﺣﺎﮐﯽ از ﻣﻄﻤﺌﻦ ﺑﻮدن ﻧﺘﺎﯾﺞ رﺗﺒﻪﻫﺎ و دﻗﺖ ﺑﺎﻻي روش ﭘﯿﺸﻨﻬﺎدي ﻣﯽﺑﺎﺷﺪ. ﺑﺤﺚ و ﻧﺘﯿﺠﻪﮔﯿﺮي: ﻧﺘﺎﯾﺞ ﺑﯿﺎنﮔﺮ ﺗﻤﺮﮐﺰ رﺗﺒﻪﻫﺎي ﺑﺎﻻي آﻟﻮدﮔﯽ در ﻣﺮﮐﺰ دﺷﺖ و ﺗﺎ ﺣﺪودي در ﻧﻮاﺣﯽ ﺷﻤﺎل و ﺷﻤﺎل ﻏﺮﺑﯽ دﺷﺖ ﺑﻪ دﻟﯿﻞ وﺟﻮد ﺻﻨﺎﯾﻊ آﻻﯾﻨﺪه ﻗﺎﺑﻞ ﺗﻮﺟﻪ و دﭘﻮي اﻧﺒﺎرﻫﺎي ﺳﻤﻮم و ﮐﻮدﻫﺎي ﮐﺸﺎورزي در اﯾﻦ ﻣﻨﺎﻃﻖ ﻣﯽﺑﺎﺷﺪ. ﺑﺮ ﻣﺒﻨﺎي روﯾﮑﺮد اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﻣﯽﺗﻮان ﺑﯿﺎن ﻧﻤﻮد ﮐﻪ اﯾﻦ روش ﺑﻪ ﺳﺎدﮔﯽ ﻗﺎﺑﻠﯿﺖ اﺟﺮا در ﻫﺮ دﺷﺖ را ﺗﻨﻬﺎ ﺑﺎ اﻧﺪازهﮔﯿﺮي ﭘﺎراﻣﺘﺮﻫﺎي ﮐﯿﻔﯽ داﺷﺘﻪ و ﻣﯽﺗﻮاﻧﺪ ﺑﺎ دﻗﺖ ﺑﺎﻻﯾﯽ رﺗﺒﻪ آﻟﻮدﮔﯽ ﻧﻤﻮﻧﻪﻫﺎي ﮐﯿﻔﯽ را ﺑﻪ ﺧﺼﻮص در ﻣﻮاردي ﮐﻪ ارزﯾﺎﺑﯽ ﮐﯿﻔﯿﺖ آب ﺑﺮاي ﻣﺼﺎرف ﺷﺮب ﻣﺪﻧﻈﺮ ﺑﺎﺷﺪ، ﻣﻮرد ﻣﺤﺎﺳﺒﻪ ﻗﺮار دﻫﺪ.

Introduction: Assessing the quality of available water is especially important to meet drinking needs. Therefore, it is important to prepare and formulate an approach that can provide a more appropriate evaluation with higher accuracy and taking into account the inaccuracies caused by instrumental errors and measurements. The aim of this study was to evaluate the groundwater quality of Zanjan plain based on a method similar to fuzzy ideal solution. Material and Methods:To achieve this goal, 57 and 59 groundwater quality samples in dry and wet seasons were used and the 28 quality parameters were analyzed in each sample. The relative closeness coefficient of each samples were determined based on fuzzy weight specified by the opinions of experts in this field for each quality parameters and the fuzzy decision matrix based on drinkable water quality standards. By calculating the relative closeness coefficient of each samples, the contamination ranking for each sample was determined. Results and Discussion: The results show that the more polluted areas are mainly concentrated in the center and northwest of the plain and this is in complete harmony with the location of industrial centers (such as lead and zinc complexes) and the hydrogeological characteristics of the aquifer. In order to evaluate the accuracy of the ranking, the results of the proposed method were compared with the definite case of the method similar to the ideal solution. Examination of the qualitative parameters related to rank 1 (lowest pollution rate) shows that most of the parameters in this rank, which should represent the lowest pollution rate, have high values in the definite method compared to the fuzzy method (for example, the amoun of the arsenic parameter located in rank 1 of the definite and fuzzy methods is equal to 0.4 and 0 micrograms per liter, respectively) and this has been repeated in reverse regarding the 59th rank (maximum pollution rate), which indicates the reliability of the rankings and the high accuracy of the proposed method. Conclusion: The results showed that the pollution is concentrated in the central plains and partly in the North and Northwest plain due to the significant polluting industries, pesticides, and manure storage depot in these areas. Based on proposed approach can be calculated the rank pollution of groundwater quality samples with high accuracy, especially in cases where the assessment of water quality for drinking purposes must be considered.