ﺑﺮرﺳﯽ ﺳﯿﻞ ﮔﯿﺮي اراﺿﯽ ﭘﺎﯾﯿﻦ دﺳﺖ ﺗﺤﺖ ﺳﻨﺎرﯾﻮ ﻫﺎي ﻣﺨﺘﻠﻒ ﻧﺎﺷﯽ از ﺷﮑﺴﺖ ﺳﺪ ﺧﺎﮐﯽ ﻗﺮه آﻗﺎچ

Investigation of Flooding of Downstream Lands under different Scenarios due to Failure of Ghare Aghach Earth Dam

ﺷﺒﯿﻪ ﺳﺎزي ﺷﮑﺴﺖ ﺳﺪ و ﻫﻤﭽﻨﯿﻦ ﺑﺮرﺳﯽ ﺳﯿﻼب ﻧﺎﺷﯽ از آن ﻣﯽ ﺗﻮاﻧﺪ ﻣﻮرد اﺳﺘﻔﺎده ﺑﻬﺮهﺑﺮداران ﺳﺪ ﻗﺮار ﺑﮕﯿﺮد. در ﺗﺤﻘﯿﻖ ﺣﺎﺿﺮ ﺑﻪ ﺑﺮرﺳﯽ ﭘﻬﻨﻪ ﺑﻨﺪي ﺳﯿﻼب ﻧﺎﺷﯽ از ﺷﮑﺴﺖ ﺳﺪ ﺧﺎﮐﯽ ﻗﺮه آﻗﺎچ از ﻧﻮع ﻧﺸﺖ ﺷﺮﯾﺎﻧﯽ در 3 ﺳﻨﺎرﯾﻮ ﻣﺘﻔﺎوت ﮐﻪ ﻣﻨﺠﺮ ﺑﻪ ﺷﮑﺴﺖ ﺳﺪ ﮔﺮدد، در ﻧﺮم اﻓﺰار HEC-RAS ﭘﺮداﺧﺘﻪ ﺷﺪه اﺳﺖ. ﻫﻤﻪ ﭘﺎراﻣﺘﺮ ﻫﺎي ﻧﺎﺷﯽ از ﺷﮑﺴﺖ ﺳﺪ ﺑﺎ اﺳﺘﻔﺎده از رواﺑﻂ Froehlich ﻣﺤﺎﺳﺒﻪ ﺷﺪ. در ﻧﻬﺎﯾﺖ دﺑﯽ ﻣﺤﺎﺳﺒﻪ ﺷﺪه از راﺑﻄﻪ Froehlich ﺑﺎ دﺑﯽ ﻣﺸﺎﻫﺪه ﺷﺪه از ﻧﺮماﻓﺰار HEC-RAS ﻣﻮرد ﺗﺤﻠﯿﻞ آﻣﺎري ﻗﺮار ﮔﺮﻓﺖ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﺑﯿﺸﺘﺮﯾﻦ دﺑﯽ اوج ﻣﺸﺎﻫﺪه ﺷﺪه ﻧﺎﺷﯽ از ﺷﮑﺴﺖ ﺳﺪ در ﻧﺮماﻓﺰار HEC-RAS ﻣﺮﺑﻮط ﺑﻪ ﺳﻨﺎرﯾﻮ ﺳﻮم ﺑﻮده و ﻣﻌﺎدل 8935/64 ﻣﺘﺮ ﻣﮑﻌﺐ ﺑﺮ ﺛﺎﻧﯿﻪ ﻣﯽ ﺑﺎﺷﺪ. اﯾﻦ در ﺣﺎﻟﯿﺴﺖ ﮐﻪ ﮐﻤﺘﺮﯾﻦ دﺑﯽ اوج ﻣﺸﺎﻫﺪه ﺷﺪه ﻧﺎﺷﯽ از ﺷﮑﺴﺖ ﺳﺪ در ﻧﺮم اﻓﺰار HEC-RAS ﻣﺮﺑﻮط ﺑﻪ ﺳﻨﺎرﯾﻮ اول ﺑﻮده و ﻣﻌﺎدل 8231/78 ﻣﺘﺮ ﻣﮑﻌﺐ ﺑﺮ ﺛﺎﻧﯿﻪ ﻣﯽ ﺑﺎﺷﺪ. ﺑﺮ اﺳﺎس ﺗﻠﻔﯿﻖ ﻧﺘﺎﯾﺞ ﺷﮑﺴﺖ ﺳﺪ ﺑﺎ ﻣﺪل ﻫﯿﺪروﻟﯿﮑﯽ HEC-RAS در Google Earth، ﺑﯿﺸﺘﺮﯾﻦ ﻣﺴﺎﺣﺖ آﺑﮕﺮﻓﺘﮕﯽ در ﺳﻨﺎرﯾﻮ ﺳﻮم اﺗﻔﺎق اﻓﺘﺎده و ﺣﺪوداً ﻣﻌﺎدل 22/8 ﮐﯿﻠﻮﻣﺘﺮ ﻣﺮﺑﻊ و ﮐﻤﺘﺮﯾﻦ ﻣﺴﺎﺣﺖ آﺑﮕﺮﻓﺘﮕﯽ ﻣﺮﺑﻮط ﺑﻪ ﺳﻨﺎرﯾﻮ اول و ﺣﺪوداً ﻣﻌﺎدل 21/8 ﮐﯿﻠﻮﻣﺘﺮ ﻣﺮﺑﻊ اﺳﺖ. ﻫﺮ ﭼﻨﺪ ﻣﺪل HEC-RAS دﻗﯿﻖ ﺗﺮ اﺳﺖ، اﻣﺎ ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﻣﻘﺪار ﻫﻤﺒﺴﺘﮕﯽ دﺑﯽ اوج ﻣﺤﺎﺳﺒﻪ ﺷﺪه ﻧﺎﺷﯽ از ﺷﮑﺴﺖ ﺳﺪ ﺑﺎ اﺳﺘﻔﺎده از راﺑﻄﻪ Froehlich و دﺑﯽ اوج ﻣﺸﺎﻫﺪه ﺷﺪه ﻧﺎﺷﯽ از ﺷﮑﺴﺖ ﺳﺪ ﺑﺎ اﺳﺘﻔﺎده از ﻧﺮماﻓﺰار HEC-RAS ﺑﻪ ﻣﯿﺰان 0/9968 ﻧﺸﺎن از دﻗﺖ ﺑﺎﻻي ﻣﺪلﺳﺎزي ﻣﯽ ﺑﺎﺷﺪ. ﮐﺎﻟﯿﺒﺮاﺳﯿﻮن و ﺗﻠﻔﯿﻖ ﻧﺘﺎﯾﺞ ﻣﺪل ﻫﯿﺪروﻟﯿﮑﯽ ﺷﮑﺴﺖ ﺳﺪ ﻫﻤﺎﻧﻨﺪ HEC-RAS ﺑﺎ ﻧﺮم اﻓﺰارﻫﺎي GIS ﻣﻨﺠﺮ ﺑﻪ اراﺋﻪ دﯾﺪﮔﺎهﻫﺎي ﻣﻨﺎﺳﺐ از وﺿﻌﯿﺖ ﺳﯿﻞ ﺧﯿﺰي ﻣﻨﺎﻃﻖ ﭘﺎﯾﯿﻦدﺳﺖ ﻣﯽﮔﺮدد ﮐﻪ در ﻣﺪﯾﺮﯾﺖ ﺑﺤﺮان ﻣﻨﺎﺑﻊ آب ﺑﺴﯿﺎر ﮐﺎرﮔﺸﺎ اﺳﺖ.

Simulation of dam failure as well as flood investigation can be used by dam operators. In the present study, the flood zoning due to the piping of Ghare Aghach earth dam in 3 different scenarios that lead to the failure of the dam has been investigated in HEC-RAS software. All parameters due to dam failure were calculated using Froehlich equations. Finally, the flow rate calculated from Froehlich method with the observed flow rate from HEC-RAS software was statistically analyzed. The results showed that the highest peak flow observed due to dam failure in HEC-RAS software is related to the third scenario and is equal to 8935.64 cubic meters per second. However, the lowest peak flow observed due to dam failure in HEC-RAS software is related to the first scenario and is equal to 8231.78 cubic meters per second. Linked results of HEC-RAS software with the Google Earth model show that the highest flooding area occurred in the third scenario and was approximately equal to 22.8 square kilometers and the lowest flooding area is related to the first scenario and approximately equal to 21.8 square kilometers. Correlation due to dam failure using the Froehlich method and the observed peak flow using HEC-RAS software equal to 0.9968 which indicates high accuracy of modeling. Calibration and applying the linked results of the hydraulic models of failure dam as well as HEC-RAS with GIS software can be useful in downstream flood zoning for water crisis management.