ارزيابي اثرات تغيير اقليم بر تغييرات تبخير و تعرق پتانسيل در دشت مغان با سناريوهاي RCPs

Assessment effects of climate change on changes in potential evapotranspiration in the Moghan Plain by RCPs

ﺗﻐﯿﯿﺮ اﻗﻠﯿﻢ ﭘﺪﯾﺪهاي ﺗﺄﺛﯿﺮﮔﺬار ﺑﺮ ﺑﺴﯿﺎري از ﻓﺮاﯾﻨﺪﻫﺎي ﻃﺒﯿﻌﯽ از ﺟﻤﻠﻪ ﭼﺮﺧﻪ ﻫﯿﺪروﻟﻮژي اﺳﺖ. ﺗﺒﺨﯿﺮ و ﺗﻌﺮق ﻧﯿﺰ ﺑﻪ ﻋﻨﻮان ﯾﮑﯽ از ﺑﺨﺶﻫﺎي ﭼﺮﺧﻪ ﻫﯿﺪروﻟﻮژي، دﺳﺖﺧﻮش اﯾﻦ ﺗﻐﯿﯿﺮات ﺧﻮاﻫﺪ ﺑﻮد. ﺑﻪدﻟﯿﻞ اﻫﻤﯿﺖ ﺗﺒﺨﯿﺮ و ﺗﻌﺮق در ﻣﺪﯾﺮﯾﺖ ﻣﻨﺎﺑﻊ آب و ﺑﺮﻧﺎﻣﻪرﯾﺰي ﮐﺸﺎورزي، ﭘﮋوﻫﺶ ﺣﺎﺿﺮ، ﺑﺎ ﻫﺪف ﺑﺮرﺳﯽ اﺛﺮ ﺗﻐﯿﯿﺮ اﻗﻠﯿﻢ ﺑﺮ اﯾﻦ ﭘﺎراﻣﺘﺮ ﻣﻬﻢ و ﺗﺎﺛﯿﺮﮔﺬار، در دﺷﺖ ﻣﻐﺎن اﻧﺠﺎم ﺷﺪه اﺳﺖ. ﺑﺪﯾﻦﻣﻨﻈﻮر، از ﻣﺪل ﮔﺮدش ﻋﻤﻮﻣﯽ ﺟﻮي و اﻗﯿﺎﻧﻮﺳﯽ HadGEM2 ﺗﺤﺖ ﺳﻨﺎرﯾﻮﻫﺎي RCPs و رﯾﺰﻣﻘﯿﺎس ﮔﺮدان Lars-WG6 در دو دوره 2011-2030 و 2030-2060 اﺳﺘﻔﺎده ﺷﺪ. ﻫﻤﭽﻨﯿﻦ، ﺑﺮاي ﻣﺤﺎﺳﺒﻪ ﺗﺒﺨﯿﺮ و ﺗﻌﺮق ﻧﯿﺰ از روشﻫﺎي ﭘﻨﻤﻦ-ﻣﺎﻧﺘﯿﺚ و ﻫﺎرﮔﺮﯾﻮز–ﺳﺎﻣﺎﻧﯽ اﺳﺘﻔﺎده ﺷﺪه اﺳﺖ. اﯾﻦ ﭘﮋوﻫﺶ، ﻧﺸﺎن داد ﮐﻪ ﺗﺒﺨﯿﺮ و ﺗﻌﺮق ﻣﺤﺎﺳﺒﺎﺗﯽ ﺑﺎ روش ﭘﻨﻤﻦ-ﻣﺎﻧﺘﯿﺚ در دﺷﺖ ﻣﻐﺎن در ﻫﺮﯾﮏ از ﺳﻨﺎرﯾﻮﻫﺎ و در دورهﻫﺎي 2030- 2011 و 2030-2060 از ﺷﺶ اﻟﯽ ﺗﺎ 8/4 درﺻﺪ ﻧﺴﺒﺖ ﺑﻪ ﺳﺎلﻫﺎي ﻣﺸﺎﻫﺪاﺗﯽ اﻓﺰاﯾﺶ ﺧﻮاﻫﺪ داﺷﺖ. ﻫﻤﭽﻨﯿﻦ، ﻣﺸﺎﻫﺪه ﺷﺪ ﮐﻪ ﺗﺒﺨﯿﺮ و ﺗﻌﺮق ﻣﺤﺎﺳﺒﺎﺗﯽ از روش ﻫﺎرﮔﺮﯾﻮز-ﺳﺎﻣﺎﻧﯽ در دﺷﺖ ﻣﻐﺎن، در ﻫﺮ ﯾﮏ از ﺳﻨﺎرﯾﻮﻫﺎ و در دوره ﻫﺎي 2011-2030 و 2030-2060 از 4/5 اﻟﯽ 7/7 درﺻﺪ ﻧﺴﺒﺖ ﺑﻪ ﺳﺎلﻫﺎي ﻣﺸﺎﻫﺪاﺗﯽ اﻓﺰاﯾﺶ ﺧﻮاﻫﺪ ﯾﺎﻓﺖ. اﯾﻦ اﻓﺰاﯾﺶﻫﺎ ﻣﻮﺟﺐ اﻓﺰاﯾﺶ ﻧﯿﺎز آﺑﯽ ﺷﺒﮑﻪﻫﺎي آﺑﯿﺎري و زﻫﮑﺸﯽ ﻣﻐﺎن و ﺧﺪآﻓﺮﯾﻦ در ﻣﺎهﻫﺎي ﭘﺮﻧﯿﺎز ﻣﯽﺷﻮد ﮐﻪ اﺗﺨﺎذ راﻫﮑﺎرﻫﺎي ﻣﻨﺎﺳﺐ ﺑﺮاي ﺳﺎزﮔﺎري ﺑﺎ ﺷﺮاﯾﻂ ﺗﻐﯿﯿﺮ اﻗﻠﯿﻢ را اﯾﺠﺎب ﻣﯽﮐﻨﺪ

Climate change is an effective phenomenon on many natural processes, including hydrologic cycle. The evapotranspiration as one of the parts of the hydrologic cycle will be at the forefront of these changes. Due to the importance of evapotranspiration in water resources management and agricultural planning, the present study was conducted to investigate the effect of climate change on this parameter in Moghan Plain. For this purpose, the HadGEM2 atmospheric and oceanic circulation model was used under RCPS and Lars-WG6 downscaling in 2011-2030 and 2030-2060 periods. Also, Penman-Monteith and Hargreaves-Samani methods were used to calculate evapotranspiration. This study showed an increase of 6 to 8.4% of calculated evapotranspiration with Penman-Monteith method in each of the scenarios in 2030-2011 and 2030-2060 periods compared to the observed years. Also, calculated evapotranspiration of the Hargreaves-Samani method will increase from 4.5 to 7.7% in each scenario in 2030-2011 and 2030-2030 periods compared to the observation years. These increases affects on water demands of Moghan and Khodafarin irrigation and drainage networks in the maximum months, which requires appropriate solutions to adapt to climate change conditions.