برآورد ارزش سايه‌اي و هزينه‌هاي جانبي شوري‌آب زيرزميني در بخش كشاورزي

Estimation of Shadow Price and External Cost of Groundwater Salinity in Agricultural Sector

زﻣﯿﻨﻪ و ﻫﺪف: رﺷﺪ ﺑﻬﺮه ﺑﺮداري از ﻣﻨﺎﺑﻊ آﺑﯽ ﺟﻬﺖ ﺗﺄﻣﯿﻦ ﻣﺼﺎرف ﮐﺸﺎورزي ﻣﻨﺠﺮ ﺑﻪ ﺑﺮداﺷﺖ ﺑﯽ روﯾﻪ از آﺑﺨﻮان ﻫﺎ و ﮐﺎﻫﺶ ﺳﻄﺢ آب زﯾﺮزﻣﯿﻨﯽ ﮐﺸﻮر ﺷﺪه اﺳﺖ. اﯾﻦ ﻣﺴﺌﻠﻪ ﺑﺎ اﻧﺘﺸﺎر ﭘﺴﺎب ﻫﺎي آﻻﯾﻨﺪه در ﻣﺤﯿﻂ زﯾﺴﺖ ﺑﺎﻋﺚ اﻓﺰاﯾﺶ ﺷﻮري ﺷﺪه و ﻗﺪرت ﺗﻮﻟﯿﺪي ﻣﺰارع ﮐﺸﺎورزي را ﺑﺎ ﺗﻬﺪﯾﺪ ﺟﺪي روﺑﺮو ﺳﺎﺧﺘﻪ اﺳﺖ. از اﯾﻦ رو اﻧﺪازه ﮔﯿﺮي ﻫﺰﯾﻨﻪ ﻫﺎي آﻟﻮدﮔﯽ ﻧﺎﺷﯽ از ﺗﻮﻟﯿﺪ ﻣﺤﺼﻮﻻت ﻣﺨﺘﻠﻒ و ﺗﻌﯿﯿﻦ ارزش ﺳﺎﯾﻪ اي آﻻﯾﻨﺪه ﻫﺎ ﺑﺴﯿﺎر ﺣﺎﺋﺰ اﻫﻤﯿﺖ اﺳﺖ. ﺑﺮاي اﯾﻦ ﻣﻨﻈﻮر در ﭘﮋوﻫﺶ ﺣﺎﺿﺮ ﺑﺎ اﺳﺘﻔﺎده از آﻣﺎرﻫﺎي ﺑﺨﺶ ﮐﺸﺎورزي در اﺳﺘﺎن ﻫﺎي ﻣﺨﺘﻠﻒ در دورة زﻣﺎﻧﯽ 1379-1394 ﺑﻪ ﻣﺤﺎﺳﺒﮥ ارزش ﺳﺎﯾﻪ اي ﺷﻮري آب زﯾﺮزﻣﯿﻨﯽ اﯾﺮان ﭘﺮداﺧﺘﻪ ﺷﺪه اﺳﺖ. روش ﺑﺮرﺳﯽ: در اﯾﻦ راﺳﺘﺎ اﺑﺘﺪا ﺗﺎﺑﻊ ﻓﺎﺻﻠﻪ ﺳﺘﺎﻧﺪه ﺟﻬﺖ دار در ﻓﺮم ﺗﺒﻌﯽ درﺟﻪ دوم ﺗﺼﺮﯾﺢ ﺷﺪ و ﺑﺎ روﯾﮑﺮد ﺑﺮﻧﺎﻣﻪ رﯾﺰي رﯾﺎﺿﯽ ﺑﺮآورد ﺷﺪ. در اداﻣﻪ ﻣﯿﺰان ﻧﺎﮐﺎراﯾﯽ ﺗﮑﻨﯿﮑﯽ زﯾﺴﺖ ﻣﺤﯿﻄﯽ اﺳﺘﺎن ﻫﺎ در ﻓﻌﺎﻟﯿﺖ ﮐﺸﺎورزي ارزﯾﺎﺑﯽ ﺷﺪه و ﻧﻬﺎﯾﺘﺎ ارزش ﺳﺎﯾﻪ اي ﺷﻮري آب زﯾﺮزﻣﯿﻨﯽ ﺑﺮآورد ﺷﺪ. ﯾﺎﻓﺘﻪﻫﺎ: ﻧﺘﺎﯾﺞ ﻧﺸﺎن ﻣﯽ دﻫﺪ ﮐﻪ اﺳﺘﺎن ﻫﺎي ﮐﺸﻮر از ﻟﺤﺎظ ﻣﯿﺰان ﻧﺎﮐﺎراﯾﯽ ﺗﮑﻨﯿﮑﯽ ﺷﺮاﯾﻂ ﻣﺘﻔﺎوﺗﯽ دارﻧﺪ. ﻣﺘﻮﺳﻂ ارزش ﺗﺎﺑﻊ ﻓﺎﺻﻠﻪ ﺳﺘﺎﻧﺪه ﺟﻬﺖ دار اﯾﺮان ﺑﺮاﺑﺮ ﺑﺎ 0/228 ﻣﯽ ﺑﺎﺷﺪ. ﻫﻤﭽﻨﯿﻦ ﻣﯿﺎﻧﮕﯿﻦ ارزش ﺳﺎﯾﻪ اي ﺷﻮري آب زﯾﺮزﻣﯿﻨﯽ اﯾﺮان ﺑﺮاﺑﺮ ﺑﺎ 0/278 ﻣﯿﻠﯿﺎرد رﯾﺎل ﺑﻪ ازاي ﻫﺮ ﻣﯿﮑﺮوزﯾﻤﻨﺲ ﺑﺮ ﺳﺎﻧﺘﯽﻣﺘﺮ اﺳﺖ. ﺑﺤﺚ و ﻧﺘﯿﺠﻪﮔﯿﺮي: ﭘﯿﺸﻨﻬﺎد ﻣﯽﺷﻮد ﮐﻪ ﺳﯿﺎﺳﺖﻫﺎي دوﻟﺖ ﺑﺮاي ﮐﻨﺘﺮل ﺷﻮري آب زﯾﺮزﻣﯿﻨﯽ ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ وﯾﮋﮔﯽﻫﺎي ﻫﺮ ﻣﻨﻄﻘﻪ ﺗﺪوﯾﻦ و اﺟﺮا ﺷﻮد و اوﻟﻮﯾﺖ ﺑﺎ اﺳﺘﺎنﻫﺎﯾﯽ ﺑﺎﺷﺪ ﮐﻪ ﻗﯿﻤﺖ ﺳﺎﯾﻪاي در آنﻫﺎ ﮐﻤﺘﺮ اﺳﺖ.

Background and Objective: The use of groundwater resources for agricultural purposes has led to an excessive withdrawal of aquifers and a reduction in groundwater levels in Iran. This issue has increased the salinity and has seriously threatened the agricultural production farms. Therefore, it is important to measure the cost of pollution caused by the production of different products and determine their shadow value. For this purpose, the shadow price of groundwater salinity in different provinces has been estimated during the period of 1964-1999. Method: In this study, directional output distance function in the quadratic form was used to determine the environmental efficiency and shadow price of groundwater salinity. Findings: The technical inefficiency and shadow value of salinity of the provinces was estimated in the agricultural activity. The results show that the provinces of the country have different conditions in terms of technical inefficiency. The average value of the directional output distance function of Iran is 0.228. Also, the average shadow value of salinity in the groundwater of Iran is 0.278 billion Rials per μS⁄cm. Discussion and Conclusion: It is suggested that policies should be developed to control the salinity of groundwater, taking into account the characteristics of each region, and priority should be given to provinces with less shadow prices.