كليدواژه :
سيل , تحليل هيدرولوژيكي , مديريت بحران , حوضه آبريز كشكان
چكيده فارسي :
ﻫﻤﻮاره ﻃﻐﯿﺎن آب و ﺳﺮازﯾﺮ ﺷﺪن آن ﺑﻪ اﻣﺎﮐﻦ ﻣﺴﮑﻮﻧﯽ، از ﺟﻤﻠﻪ ﺣﻮادث ﻃﺒﯿﻌﯽ ﺷﺎﯾﻊ در اﯾﺮان ﭘﺲ از زﻟﺰﻟﻪ اﺳﺖ ﮐﻪ ﺣﯿﺎت ﺑﺸﺮ را ﺑﻪ ﻣﺨﺎﻃﺮه ﻣﯽاﻧﺪازد. ﺑﯿﻦ ﺳﺎلﻫﺎي 2000 ﺗﺎ 2008 ﺗﻘﺮﯾﺒﺎً 99 ﻣﯿﻠﯿﻮن اﻧﺴﺎن در ﺳﺎل ﺗﻮﺳﻂ ﺳﯿﻠﺎب در ﺟﻬﺎن ﺗﺤﺖ ﺗـﺄﺛﯿﺮ ﻗﺮار ﮔﺮﻓﺘﻪاﻧﺪ. ﺣﻮﺿﻪ آﺑﺮﯾﺰ رودﺧﺎﻧﻪ ﮐﺸﮑﺎن ﺑﺎ 8 زﯾﺮ ﺣﻮﺿﻪ ﺑﻪ وﺳﻌﺖ 9275/66 ﮐﯿﻠﻮﻣﺘﺮ ﻣﺮﺑﻊ، در ﻣﺠﻤـﻮع 22/4 درﺻـﺪ از ﮐﻞ ﺣﻮﺿﻪ ﮐﺮﺧﻪ را ﺷﺎﻣﻞ ﻣﯽﺷﻮد، اﯾﻦ رودﺧﺎﻧﻪ ﺑﺎ ﻃﻮل 290 ﮐﯿﻠﻮﻣﺘﺮ و ﺷﯿﺐ 26 درﺻﺪي ﭘﺮﺷﯿﺐﺗﺮﯾﻦ و ﺳﯿﻠﺨﯿﺰﺗـﺮﯾﻦ زﯾـﺮ ﺣﻮﺿﻪ ﮐﺮﺧﻪ اﺳﺖ. ﻧﺘﺎﯾﺞ ﺗﺤﻠﯿﻞﻫﺎي آﻣﺎري ﺑﺮ دادهﻫﺎي دﺑﯽ ﻟﺤﻈﻪاي ﺣﻮﺿﻪ ﮐﺸﮑﺎن ﻧﺸـﺎن داد ﮐـﻪ از ﺳـﺎل 1342 ﺗـﺎ 1398 ﺗﻌﺪاد 58 ﺳﯿﻠﺎب ﺑﺎ ﻣﯿﺎﻧﮕﯿﻦ دﺑﯽ ﻟﺤﻈﻪاي 1062/78 ﻣﺘﺮ ﻣﮑﻌﺐ ﺣﺎدث ﺷﺪه اﺳﺖ از ﻧﻈـﺮ ﭘـﺮاﮐﻨﺶ زﻣـﺎﻧﯽ ﺗﻌـﺪاد 65 درﺻـﺪ ﺳﯿﻠﺎبﻫﺎ در ﻣﺎهﻫﺎي اﺳﻔﻨﺪ، ﻓﺮوردﯾﻦ و اردﯾﺒﻬﺸﺖ و ازﻟﺤﺎظ ﻣﯿﺰان دﺑﯽ 36 درﺻﺪ ﺳﯿﻠﺎبﻫـﺎ دﺑـﯽ آنﻫـﺎ ﺑـﯿﺶ از 1000 ﻣﺘـﺮ ﻣﮑﻌﺐ ﻣﯽﺑﺎﺷﺪ. از ﻧﻈﺮ ﻓﺮاواﻧﯽ وﻗﻮع ﺳﯿﻠﺎب دﻫﻪ 1398- 1390 ﺑﺎ 19 درﺻﺪ ﺳﯿﻠﺎب ﺑﯿﺸﺘﺮﯾﻦ ﻓﺮاواﻧﯽ را دارا و از ﻧﻈـﺮ داﻣﻨـﻪ ﺑﺰرﮔﯽ ﺳﯿﻠﺎب ﺣﺪود 14 درﺻﺪ ﺳﯿﻠﺎبﻫﺎ ﺷﺪﯾﺪ، 22 درﺻﺪ ﻣﺘﻮﺳﻂ و 64 درﺻﺪ در رﻧـﺞ ﺳـﯿﻠﺎب ﮐﻮﭼـﮏ ﻗـﺮار داﺷـﺘﻪاﻧـﺪ. ﺑﺮاﺳﺎس ﺗﻮزﯾﻊ ﮔﻤﺒﻞ در 200 ﺳﺎل ﯾﮏﺑﺎر ﺑﺎ اﺣﺘﻤﺎل وﻗﻮع 0/995 درﺻﺪ ﺳﯿﻠﺎﺑﯽ ﺑﺎ دﺑـﯽ ﻟﺤﻈـﻪاي 4489/77 ﻣﺘـﺮ ﻣﮑﻌـﺐ ﺑـﺎ ﺗﻠﺮاﻧﺲ 535/06 ﻣﺘﺮ ﻣﮑﻌﺐ در ﺣﻮﺿﻪ ﮐﺸﮑﺎن ﺣﺎدث ﻣﯽﮔﺮدد. ﺑﺮ اﺛﺮ ﺳﯿﻞ 12 ﻓﺮوردﯾﻦ ﻣﺎه ﺗﻌـﺪاد 14 ﻧﻔـﺮ ﺟـﺎن ﺧـﻮد را از دﺳﺖ دادﻧﺪ و ﻣﯿﺰان ﺧﺴﺎرت در ﺣﺪود 10301/4 ﻣﯿﻠﯿﺎرد ﺗﻮﻣﺎن ﺑﺮآورد ﮔﺮدﯾﺪ. ﻋﻤﺪه دﻟﺎﯾﻞ وﻗـﻮع ﺳـﯿﻠﺎﺑﯽ ﺑـﺎ دﺑـﯽ ﻟﺤﻈـﻪاي 6000 ﻣﺘﺮ ﻣﮑﻌﺐ در ﺛﺎﻧﯿﻪ در ﺣﻮﺿﻪ ﮐﺸﮑﺎن را ﻣﯽﺗﻮان ﺑﻪ وﻗﻮع ﺑﺎرش ﺑـﺎ ﻣﯿـﺎﻧﮕﯿﻦ 112/3 ﻣﯿﻠـﯽﻣﺘـﺮ در روز 12 ﻓـﺮوردﯾﻦ و 321/5 ﻣﯿﻠﯽﻣﺘﺮي ﺑﻪ ﻣﺪت 9 روز از 4 ﺗﺎ 12 ﻓﺮوردﯾﻦ در ﺳﻄﺢ ﺣﻮﺿﻪ ﮐﺸﮑﺎن، ﺣﺎدث ﺷﺪن ﺳﯿﻠﯽ ﺑﺎ دﺑﯽ ﻟﺤﻈﻪاي 3350 ﻣﺘﺮ ﻣﮑﻌﺐ در ﻣﻮرﺧﻪ 5 ﻓﺮوردﯾﻦ 1398، ﻧﺒﻮد ﺳﺪ ﻣﺨﺰﻧﯽ ذﺧﯿﺮهاي ﻗﺎﺑﻞ ﻣﻠﺎﺣﻈﻪ ﺑﺮاي ﻣﻬﺎر ﺳﯿﻠﺎب، ﺗﺄﺛﯿﺮ ﭘﻞ ﺑﺎﺑﺎزﯾﺪ ﺑﻪ ﻋﻨﻮان ﺳـﺪ و ﺟﻤﻊ ﺷﺪن رواﻧﺎب در ﭘﺸﺖ ﭘﻞ ﺗﺎ ﺷﻌﺎع 5 ﮐﯿﻠﻮﻣﺘﺮي و رﺳﯿﺪن رﻣﭗ ﭘﻞ ﺑـﻪ ﻧﻘﻄـﻪ ﺷﮑﺴـﺖ و درﻧﺘﯿﺠـﻪ اﻓـﺰاﯾﺶ ﻣﻘـﺪار و ﺳﺮﻋﺖ ﺟﺮﯾﺎن دﺑﯽ ﺳﯿﻠﺎﺑﯽ ﺑﻪ ﺳﻤﺖ ﺷﻬﺮ ﭘﻠﺪﺧﺘﺮ، ﮐﺎﻫﺶ ﺑﺴﺘﺮ رودﺧﺎﻧﻪ ﺑﯿﻦ 1 ﺗﺎ 13 ﻣﺘﺮ در ﺑﺎزﺳﺎزي دﯾﻮاره ﺳـﺎﺣﻠﯽ ﺑﻌـﺪ از ﺳﯿﻞ 15 ﺑﻬﻤﻦ 1384 در ﻧﺘﯿﺠﻪ ﮐﺎﻫﺶ ﻇﺮﻓﯿﺖ آﺑﮕﺬري رودﺧﺎﻧﻪ ﮐﺸﮑﺎن در ﺷﻬﺮ ﭘﻠﺪﺧﺘﺮ ﻫﻨﮕﺎم ﺳﯿﻞ را ﻣﯽﺗﻮان اﺷﺎره ﮐﺮد.
چكيده لاتين :
Water floods and floods in residential areas have always been one of the most common natural disasters in Iran after the earthquake that endanger human life. Between 2000 and 2008, approximately 99 million people are affected by floods worldwide each year. Kashkan River Basin with 8 sub-basins with an area of 9275.66 square kilometers, constitutes 22.4 percent of total Karkheh basin, with 290km length and 26 percent slope of the steepest and most flooded Karkheh basin. The results of statistical analysis on the instantaneous discharge data of Kashkan basin showed that from 1963 to 2019, 58 floods with average discharge moment of 1062.78 cubic meters occurred. In terms of time distribution, 65 percent of the floods in March, April and May and in terms of discharge rate 36 percent of the floods are more than 1000 cubic meters. The highest frequency of floods was observed in 1990-90 with 19 percent of floods and 14 percent of floods were severe, 22 percent moderate and 64 percent small flood. According to the Gamble distribution, a 200-year flood with a probability of 0.995 percent flood occurring at an instantaneous discharge of 4489.77 cubic meters with a tolerance of 535.06 cubic meters in the Kashkan Basin. As a result of the floods on 1 April, 14 people were killed and the damage was estimated to be 103.014 billion USD. The main causes of floods with an instantaneous discharge of 6,000 cubic meters per second in the Kashkan Basin can be attributed to precipitation with an average rainfall of 112.3 mm on 1 April and 321.5 mm for 9 days from 24 Mars to 1 April, respectively. Kashkan Basin, The occurrence of a flood with an instantaneous discharge of 3350 cubic meters on 5 March 2019, the absence of a significant reservoir dam for flood control, Impact of Babazid Bridge as a dam and runoff behind the bridge up to a radius of 5 kilometers and reaching the bridge ramp to the breaking point, thereby increasing the amount and velocity of the flood discharge to Poldokhtar, Decrease in river bed between 1 and 13 m in coastal wall reconstruction after flood on 4 February 2005 as a result of reduced capacity of Kashkan River in Poldokhtar during floods.
