برآورد و محاسبه تبخيرو تعرق واقعي با استفاده از مدل توازن انرژي SEBS و تصاوير ماهواره اي لندست 8 (مطالعه موردي: حوضه آبريز بختگان-مهارلو)

Estimation and Calculation of Actual Evatranspiration Using SEBS Energy Balance Model and Landsat 8 Satellite Imagery (Case study: Bakhtegan-Maharlo Basin)

اﺳﺘﻔﺎده از ﻣﻨﺎﺑﻊ آﺑﯽ ﻧﯿﺎز ﺑﻪ ﺗﻌﯿﯿﻦ اﺟﺰاي ﭼﺮﺧﻪ ﻫﯿﺪروﻟﻮژﯾﮑﯽ دارد. ﺑﻪ ﻃﻮري ﮐﻪ درك ﺳﯿﺴﺘﻢﻫﺎي ﻃﺒﯿﻌﯽ و ﻗﻮاﻧﯿﻦ ﻓﯿﺰﯾﮑﯽ ﮐﻪ ﻫﺮ ﺟﺰء ﭼﺮﺧﻪ ﻫﯿﺪروﻟﻮژﯾﮑﯽ را ﻣﺪﯾﺮﯾﺖ ﻣﯽﮐﻨﻨﺪ، ﺑﻪ ﻣﻨﻈﻮر ﻣﺪﯾﺮﯾﺖ ﻣﻨﺎﺑﻊ آب ﺑﺴﯿﺎر ﻣﻬﻢ و ﺿﺮوري اﺳﺖ. ﯾﮑﯽ از اﺟﺰاي ﻣﻬﻢ ﭼﺮﺧﻪ ﻫﯿﺪروﻟﻮژﯾﮑﯽ، ﺗﺒﺨﯿﺮو ﺗﻌﺮق ﻣﯽﺑﺎﺷﺪ. اﻏﻠﺐ روشﻫﺎﯾﯽ ﮐﻪ ﺗﺎﮐﻨﻮن اراﺋﻪ ﺷﺪه اﺳﺖ از اﻧﺪازهﮔﯿﺮيﻫﺎي ﻧﻘﻄﻪاي ﺑﺮاي ﺗﺨﻤﯿﻦ ﺗﺒﺨﯿﺮ و ﺗﻌﺮق اﺳﺘﻔﺎده ﻣﯽﮐﻨﻨﺪ، ﻟﺬا ﻓﻘﻂ ﻣﻨﺎﺳﺐ ﻣﻨﺎﻃﻖ در ﻣﻘﯿﺎسﻫﺎي ﺑﺴﯿﺎر ﮐﻮﭼﮏ ﺑﻮده و ﺑﻪ ﺧﺎﻃﺮ ﺷﺮاﯾﻂ ﻣﺘﻐﯿﺮ آب و ﻫﻮاﯾﯽ، ﻃﺒﯿﻌﺖ ﭘﻮﯾﺎ اﻧﺘﻘﺎل آب-ﮔﺮﻣﺎ و ﺗﻐﯿﯿﺮات ﻣﮑﺎﻧﯽ ﺗﺒﺨﯿﺮ و ﺗﻌﺮق ﻗﺎﺑﻞ ﺗﻌﻤﯿﻢ ﺑﻪ ﺣﻮﺿﻪﻫﺎي آﺑﺮﯾﺰ ﺑﺰرگ ﻧﻤﯽﺑﺎﺷﻨﺪ. ﻓﻨّﺎوري ﺳﻨﺠﺶازدور ﻣﺎﻫﻮارهاي و اﺳﺘﻔﺎده از روشﻫﺎي ﻣﺒﺘﻨﯽ ﺑﺮ ﺳﻨﺠﺶازدور از ﺟﻤﻠﻪ روشﻫﺎي ﺑﺮآورد زﻣﺎﻧﯽ و ﻣﮑﺎﻧﯽ ﺗﺒﺨﯿﺮ و ﺗﻌﺮق واﻗﻌﯽ در ﺳﻄﺢ ﺣﻮﺿﻪﻫﺎي ﮐﻮﭼﮏ و وﺳﯿﻊ ﻣﯽﺑﺎﺷﺪ. در اﯾﻦ ﺗﺤﻘﯿﻖ ﻣﻘﺪار ﺗﺒﺨﯿﺮوﺗﻌﺮق واﻗﻌﯽ ﺑﺎ اﺳﺘﻔﺎده از ﺗﺼﺎوﯾﺮ ﻣﺎﻫﻮارهاي ﻟﻨﺪﺳﺖ 8 ﺳﻨﺠﻨﺪه OLI/TIRS و ﻣﺪل ﺗﻮازن اﻧﺮژي ﺳﻄﺢ )SEBS( در ﺣﻮﺿﻪ آﺑﺮﯾﺰ ﺑﺨﺘﮕﺎن ﻣﻬﺎرﻟﻮ در اﺳﺘﺎن ﻓﺎرس ﻣﻮرد ﺑﺮآورد و ارزﯾﺎﺑﯽ ﻗﺮار ﮔﺮﻓﺘﻪ و ﺑﺎ روش ﺗﺠﺮﺑﯽ ﻓﺎﺋﻮ ﭘﻨﻤﻦ ﻣﺎﻧﺘﯿﺚ درﺳﻄﺢ ﺣﻮﺿﻪ ﻣﻮرد ﻣﻘﺎﯾﺴﻪ ﻗﺮارﮔﺮﻓﺖ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﻣﻘﺎدﯾﺮ ﺗﺒﺨﯿﺮ وﺗﻌﺮق ﺑﻪ دﺳﺖ آﻣﺪه از روش ﺗﻮازن اﻧﺮژي در ﻣﻘﺎﯾﺴﻪ ﺑﺎ روش ﻓﺎﺋﻮ ﭘﻨﻤﻦ ﻣﺎﻧﺘﯿﺚ داراي ﻣﻘﺪار ﻣﯿﺎﻧﮕﯿﻦ ﺗﻔﺎﺿﻞ ﻣﻄﻠﻖ )MAD( ﺑﺮاﺑﺮ ﺑﺎ 0/49و ﻣﻘﺪار رﯾﺸﻪ ﻣﯿﺎﻧﮕﯿﻦ ﻣﺮﺑﻌﺎت ﺧﻄﺎ )RMSE( ﺑﺮاﺑﺮ ﺑﺎ 0/62 ﻣﯿﻠﯽ ﻣﺘﺮ در روز ﺑﻮده و ﺣﺎﮐﯽ از ﻋﻤﻠﮑﺮد ﻗﺎﺑﻞ ﻗﺒﻮل و ﻣﻨﻄﻘﯽ ﻣﺪل در ﺑﺮآورد ﺗﺒﺨﯿﺮو ﺗﻌﺮق دارد.

Using water resources require the determination of components of the hydrological cycle. Understanding of natural systems and physical laws that manage each component of the hydrological cycle is important for the water resources management. One of the crucial components of the hydrological cycle is evapotranspiration. Most methods that have been presented in this study use point measurements to estimate evapotranspiration. Due to dynamic and changing nature of regional evapotranspiration is not generalizable to the basin, the applied methods are only suitable for the local areas. Technology of satellite remote sensing and remote sensing-based methods can be used for the temporal and spatial estimation of actual evapotranspiration in the small and large basins. Remote sensing data derived from satellite imagery calculates the amount of actual evapotranspiration using surface energy balances model. In this study, actual evapotranspiration at the Bakhtegan-Maharloo basin were estimated and evaluated using Landsat 8 satellite images sensor OLI/TIRS and SEBS energy balance models. The values of evapotranspiration derived from energy balance model and FAO-Penman-Monteith method were compared.The results showed that the evapotranspiration values obtained from the energy balance model has a root mean square error (RMSE) and mean absolute difference (MAD) equal to 0.62 and 0.49 mm/d, respectively, indicating its acceptable performance to estimate the evapotranspiration