تعيين مدل مناسب برآورد بار كف رودخانه ها

Determining the appropriate model for estimating river bed loads

ﺑﺮآورد ﺻﺤﯿﺢ ﻣﯿﺰان رﺳﻮﺑﺪﻫﯽ ﯾﮏ ﺣﻮزه آﺑﺨﯿﺰ از ﻣﻬﻢ ﺗﺮﯾﻦ ﻣﺴﺎﺋﻞ ﻣﻄﺮح ﺷﺪه در ﻣﻬﻨﺪﺳﯽ آب، ﻣﻬﻨﺪﺳﯽ رودﺧﺎﻧﻪ، ﻣﻨﺎﺑﻊ آب، ﺗﺄﺳﯿﺴﺎت و ﺳﺎزه ﻫـ ﺎي آﺑﯽ و ﻣﺤﯿﻂ زﯾﺴﺖ ﺑﺮاي اﺟﺮاي ﻃﺮح ﻫﺎ و ﺑﺮﻧﺎﻣﻪ ﻫﺎي ﺗﻮﺳﻌﻪ اي اﺳﺖ. ﺗﻨﻮع رﯾﺎد در ﻣﻌﺎدﻻت ﻣﺤﺎﺳﺒﻪ ﻣﻘﺪار ﺑﺎر رﺳﻮب در رودﺧﺎﻧﻪ و ﻧﺒﻮد اﻃﻼﻋﺎت در ﻣﻮرد ﻧﺤﻮه اﺳﺘﺨﺮاج ﻣﻌﺎدﻻت، اﺳﺘﻔﺎده از آن را ﻣﺸﮑﻞ ﻧﻤﻮده اﺳﺖ. در اﯾﻦ ﺗﺤﻘﯿﻖ ﭘﺲ از ﮔﺮدآوري اﻃﻼﻋﺎت ﻻزم در اﯾﺴﺘﮕﺎه ﻫﯿﺪروﻣﺘﺮي ﺑﻨﮑﻮه و ﺗﻬﯿﻪ داﻧـﻪ ﺑﻨﺪي ﺑﺴﺘﺮ رودﺧﺎﻧﻪ، ﻣﻘﺪار ﺑﺎر ﺑﺴﺘﺮ رودﺧﺎﻧﻪ در اﯾﻦ اﯾﺴﺘﮕﺎه ﻫﯿﺪروﻣﺘﺮي، ﺑﺎ اﺳﺘﻔﺎده از رﮔﺮﺳﯿﻮنﻫﺎي ﻣﺨﺘﻠﻒ و ﻣﺤﺎﺳﺒﻪ از ﻃﺮﯾﻖ ﭼﻨـﺪﯾﻦ راﺑﻄـﻪ ﺗﺠﺮﺑـﯽ اﺳﺘﻔﺎده ﺷﺪه ﺑﺮاي ﻣﺤﺎﺳﺒﻪ ﻣﻘﺪار ﺑﺎر رﺳﻮب ﮐﻒ رودﺧﺎﻧﻪ، ﻣﺤﺎﺳﺒﻪ ﮔﺮدﯾﺪ. ﻧﺘﺎﯾﺞ ﺣﺎﺻﻞ از اﯾﻦ رواﺑﻂ ﺑﺎ ﻧﺘﺎﯾﺞ ﺛﺒﺖ ﺷـﺪه در اﯾﺴـﺘﮕﺎه ﻫﯿـﺪروﻣﺘﺮي و ﺳـﺎﯾﺮ رواﺑﻂ اﺳﺘﻔﺎده ﺷﺪه ﻣﻮرد ﻣﻘﺎﯾﺴﻪ ﻗﺮار ﮔﺮﻓﺖ ﮐﻪ ﻧﺸﺎندﻫﻨﺪه اﯾﻦ ﻣﻮﺿﻮع ﺑﻮد ﮐﻪ راﺑﻄﻪ ﺗﻮﻓﺎﻟﺘﯽ ﺑﺎ ﻣﯿﺰان ﺧﻄﺎي22/71 در ﺑﺮرﺳﯽ ﺿﺮﯾﺐ RMSE ﺗﻮاﻧﺎﯾﯽ ﻗﺎﺑﻞ ﻗﺒﻮﻟﯽ در ﻣﺤﺎﺳﺒﻪ ﻣﻘﺪار ﺑﺎر ﺑﺴﺘﺮ در ﻣﻨﻄﻘﻪ ﻣﻮرد ﻣﻄﺎﻟﻌﻪ دارد، ﺑﻨﺎﺑﺮاﯾﻦ ﺑﻪ ﻋﻨﻮان ﻣﺪل ﻣﻮردﻧﻈﺮ اﻧﺘﺨﺎب ﺷﺪ. ﭘﺎراﻣﺘﺮﻫﺎي ﻣﻮﺛﺮ در راﺑﻄﻪ ﺗﻮﻓﺎﻟﺘﯽ آﻧـﺎﻟﯿﺰ ﺣﺴﺎﺳﯿﺖ ﺷﺪﻧﺪ و ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﻣﻘﺪار ﺑﺎر ﮐﻒ ﻣﺤﺎﺳﺒﻪ ﺷﺪه در اﯾﻦ روش ﺑﯿﺶ از ﻫﻤﻪ ﺑﻪ ﻣﻘﺪار ﭘﺎراﻣﺘﺮ ﺳﺮﻋﺖ ﺟﺮﯾﺎن واﺑﺴﺘﻪ اﺳﺖ و ﺗﻐﯿﯿﺮات ﺳﺮﻋﺖ ﺟﺮﯾﺎن آب در رودﺧﺎﻧﻪ، ﺗﺄﺛﯿﺮ ﺑﻪ ﺳﺰاﯾﯽ در ﻣﻘﺪار ﺑﺎر رﺳﻮﺑﯽ ﮐﻒ دارد.

Accurate estimation of sedimentation of a watershed is one of the most important issues in water engineering, river engineering, water resources, water facilities and structures, and the environment for the implementation of development plans and programs. The great variability in the equations has made it difficult to calculate the amount of sediment load in the river and the not exsit of information on how to extract the equations. In this paper, after collecting the necessary information in Benkooh hydrometric station and preparing the riverbed granulation, the amount of river bed load in this hydrometric station, using different regressions and calculating through several experimental relationships used to calculate the amount of sediment load The river floor was calculated. The results of these relationships were compared with the results recorded in the hydrometric station and other relationships used, indicating that the relationship between the tuff and the error rate of 22.71 in the RMSE coefficient of acceptable ability to calculate the amount of bed load in the area Has been studied, so it was chosen as the best model. The effective parameters in the sensativity analysis were analyzed and the results showed that the amount of floor load calculated in this method depends on the value of the flow velocity parameter and changes in water flow velocity in the river have a significant effect on the amount of sediment load.