بررسي كيفيت آب رودخانه چهل‌چاي با استفاده از شاخص IRWQIsc

زﻣﯿﻨﻪ و ﻫﺪف: ﮐﯿﻔﯿﺖ آب رودﺧﺎﻧﻪ ﻫﺎ ﻣﯽ ﺗﻮاﻧﺪ ﮐﻤﮏ ﺷﺎﯾﺎﻧﯽ ﺑﻪ ﻣﺪﯾﺮﯾﺖ و ﺑﺮﻧﺎﻣﻪ رﯾﺰي ﻣﻨﺎﺑﻊ آب ﮐﻨﺪ. اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺑﻪ ﻣﻨﻈﻮر ﺑﺮرﺳﯽ ﮐﯿﻔﯿﺖ آب رودﺧﺎﻧﻪ ﭼﻬﻞ ﭼﺎي ﺑﺎ اﺳﺘﻔﺎده از ﺷﺎﺧﺺ ﮐﯿﻔﯿﺖ آب ﻫﺎي ﺳﻄﺤﯽ اﯾﺮان IRWQISC اﻧﺠﺎم ﺷﺪه اﺳﺖ. روش ﺑﺮرﺳﯽ: در اﯾﻦ ﻣﻄﺎﻟﻌﻪ از آب رودﺧﺎﻧﻪ ﭼﻬﻞ ﭼﺎي در 7 اﯾﺴﺘﮕﺎه ﻣﺨﺘﻠﻒ در ﯾﮏ دوره 6 ﻣﺎﻫﻪ ﻧﻤﻮﻧﻪ ﺑﺮداري ﺷﺪ. ﺳﭙﺲ ﺑﻪ ﻣﻨﻈﻮر اﺳﺘﻔﺎده از ﺷﺎﺧﺺ ﮐﯿﻔﯽ IRWQISC ﻣﯿﺰان ﺑﺮﺧﯽ از ﭘﺎراﻣﺘﺮﻫﺎي ﻓﯿﺰﯾﮑﻮﺷﯿﻤﺎﯾﯽ و ﻣﯿﮑﺮوﺑﯽ در اﯾﻦ دوره ﺷﺶ ﻣﺎه اﻧﺪازه ﮔﯿﺮي ﺷﺪ. ﭘﺲ از ﻣﺤﺎﺳﺒﻪ ﻣﯿﺰان ﺷﺎﺧﺺ ﺑﺮاي ﻫﺮ اﯾﺴﺘﮕﺎه، ﺗﻐﯿﯿﺮات آن در ﻃﻮل رودﺧﺎﻧﻪ ﻣﻄﺎﻟﻌﻪ ﮔﺮدﯾﺪ. در ﻧﻬﺎﯾﺖ ﻧﺘﺎﯾﺞ ﺷﺎﺧﺺ ﮐﯿﻔﯽ IRWQISC ﺑﺎ اﺳﺘﺎﻧﺪارﻫﺎي ﻣﻮﺟﻮد ﺑﺮاي ﺷﺮب و ﮐﺸﺎورزي ﻣﻮرد ﻣﻘﺎﯾﺴﻪ ﻗﺮار ﮔﺮﻓﺖ. ﯾﺎﻓﺘﻪ ﻫﺎ: ﻧﺘﺎﯾﺞ اﯾﻦ ﺗﺤﻘﯿﻖ ﻧﺸﺎن داد ﮐﻪ ﺑﺮاﺳﺎس ﺷﺎﺧﺺ IRWQISC آب رودﺧﺎﻧﻪ ﭼﻬﻞ ﭼﺎي در رده ﮐﯿﻔﯽ ﻧﺴﺒﺘﺎ ﺧﻮب ﻗﺮار ﻣﯽ ﮔﯿﺮد. ﻫﻤﭽﻨﯿﻦ ﻣﯿﺰان ﺷﺎﺧﺺ IRWQISC در ﺟﻬﺖ ﺟﺮﯾﺎن از ﺑﺎﻻدﺳﺖ ﺑﻪ ﺳﻤﺖ ﺧﺮوﺟﯽ ﺣﻮزه ﮐﺎﻫﺶ ﻣﯽ ﯾﺎﺑﺪ ﮐﻪ ﺑﯿﺎﻧﮕﺮ ﮐﺎﻫﺶ ﮐﯿﻔﺖ آب رودﺧﺎﻧﻪ اﺳﺖ. ﻧﺘﺎﯾﺞ اﯾﻦ ﺗﺤﻘﯿﻖ ﻧﺸﺎن داد ﮐﻪ ﺑﻄﻮر ﮐﻠﯽ راﺑﻄﻪ ﻣﺴﺘﻘﯿﻤﯽ ﺑﯿﻦ دﺑﯽ رودﺧﺎﻧﻪ و ﺷﺎﺧﺺ IRWQISC وﺟﻮد دارد ﺑﻄﻮرﯾﮑﻪ ﺑﺎ اﻓﺰاﯾﺶ ﻣﯿﺰان دﺑﯽ رودﺧﺎﻧﻪ، ﻣﯿﺰان ﺷﺎﺧﺺ IRWQISC ﻧﯿﺰ اﻓﺰاﯾﺶ ﯾﺎﻓﺖ. ﺑﺤﺚ و ﻧﺘﯿﺠﻪ ﮔﯿﺮي: ﻧﺘﺎﯾﺞ اﯾﻦ ﺗﺤﻘﯿﻖ ﻧﺸﺎن دادﮐﻪ ﻣﺘﻮﺳﻂ ﻣﯿﺰان ﺷﺎﺧﺺ IRWQISC در ﻓﺼﻞ ﺑﻬﺎر از ﻓﺼﻞ ﺗﺎﺑﺴﺘﺎن ﺑﻬﺘﺮ ﺑﻮده اﺳﺖ. ﺗﻐﯿﯿﺮات دﺑﯽ و ﺷﺎﺧﺺ IRWQISC ﺣﺎﮐﯽ از ﯾﮏ راﺑﻄﻪ ﻣﺴﺘﻘﯿﻢ ﺑﯿﻦ آﻧﻬﺎﺳﺖ، ﺑﻄﻮرﯾﮑﻪ ﺑﺎ اﻓﺰاﯾﺶ ﻣﯿﺰان ﺟﺰﺋﯽ دﺑﯽ ﻣﯿﺰان ﺷﺎﺧﺺ ﻧﯿﺰ اﻓﺰاﯾﺶ ﭼﺸﻤﮕﯿﺮي داﺷﺘﻪ اﺳﺖ. ﻣﻘﺎﯾﺴﻪ ﭘﺎراﻣﺘﺮﻫﺎي اﻧﺪازه ﮔﯿﺮي ﺷﺪه ﺑﺎ اﺳﺘﺎﻧﺪارﻫﺎي ﺷﺮب و ﮐﺸﺎورزي، ﻧﺸﺎن دادﮐﻪ آب رودﺧﺎﻧﻪ ﭼﻬﻞ ﭼﺎي از ﻧﻈﺮ اﺳﺘﺎﻧﺪارﻫﺎي ﮐﺸﺎورزي ﻣﻨﺎﺳﺐ ﺑﻮده و ﻓﺎﻗﺪ اﺳﺘﺎﻧﺪارﻫﺎي ﻻزم در ﺑﺨﺶ ﺷﺮب ﻣﯽ ﺑﺎﺷﺪ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﻗﺒﻞ از ﻣﺼﺮف ﺑﺮاي ﺷﺮب ﺑﺎﯾﺪ ﺣﺪاﻗﻞ دو ﺗﺼﻔﯿﻪ ﻓﯿﺰﯾﮑﯽ و ﻣﯿﮑﺮوﺑﯽ ﺑﺮ روي آن اﻧﺠﺎم ﺷﻮد.

Background and Objective: Rivers water quality study can be a great help to water-resource management and planning. This study was conducted to investigate the water quality of Chehelchay River using the IRWQISC. Method: In this study, water samples were collected from seven different stations along Chehelchay River during a period of 6 months. In order to use IRWQISC, the physicochemical and biological some parameters were measured. After calculating the IRWQISC values for each station, the changes in the IRWQISC values were investigated along river. Then, the results of IRWQISC were compared drinking water and agriculture water standards. Findings: The results of this study showed that Chehelchay River water was situated in a relatively good quality category based on the IRWQISC. IRWQISC diminished in the flow direction from the upstream sampling point to the outlet of basin resulting in a reduction in water quality of river. Results also showed that there is a direct relationship between IRWQISC and the rate of discharge so that the value of IRWQISC increases with increasing the rate of discharge. Discussion and Conclusion: The results of this study showed that the average IRWQISC index was better than summer season in spring. Flow changes and IRWQISC index indicate a direct relationship between them, with a slight increase in the rate of fluctuation. Comparison of parameters used in IRWQISC with drinking water and agriculture water standards showed the Chehelchay River water is suitable only for agriculture uses and it cannot be used for drinking purposes. Results showed that water purification must be performed to remove fecal coliform and reduce turbidity of water before using as a drinking water source.