پتانسيل توليد سيلاب و تعيين مناطق مولد سيل با استفاده از نرم افزار ArcGIS و مدل ModClark در حوضه تالار

Flood Generation Potential and Flood Producing Area Determination Using ArcGIS Software and ModClark Model in Talar Watershed

اوﻟﻮﯾﺖ ﺑﻨﺪي ﻣﻨﺎﻃﻖ ﻣﺨﺘﻠﻒ و زﯾﺮﺣﻮﺿـــﻪ ﻫﺎ از ﻧﻈﺮ ﭘﺘﺎﻧﺴـــﯿﻞ ﺳـــﯿﻞ ﺧﯿﺰي ﺗﺄﺛﯿﺮ ﻣﻬﻤﯽ در ﻣﺪﯾﺮﯾﺖ ﺣﻮزه آﺑﺨﯿﺰ دارد. ﻫﺪف از اوﻟﻮﯾﺖﺑﻨﺪي ﺳﯿﻞ ﺧﯿﺰي در زﯾﺮﺣﻮ ﺿﻪ ﻫﺎ، اراﺋﻪ اﻟﮕﻮﯾﯽ ﺑﺮاي ﮐﻨﺘﺮل و ﮐﺎﻫﺶ ﺧﻄﺮات ﺳﯿﻞ و ارزﯾﺎﺑﯽ ﻧﻘﺶ ﻫﺮﯾﮏ از زﯾﺮﺣﻮ ﺿﻪ ﻫﺎ در دﺑﯽاوج ﻫﯿﺪروﮔﺮاف ﺳﯿﻼب ﺧﺮوﺟﯽ ﺣﻮﺿﻪ ﻣﯽ ﺑﺎﺷﺪ. در اﯾﻦ ﺗﺤﻘﯿﻖ ﺣﻮﺿﻪ ﺗﺎﻻر ﺑﺪﻟﯿﻞ وﻗﻮع ﺳﯿﻞﻫﺎي ﻣﺘﻌﺪد، ﺑﻌﻨﻮان ﻣﻨﻄﻘﻪ ﻣﻮرد ﻣﻄﺎﻟﻌﻪ اﻧﺘﺨﺎب و در اداﻣﻪ ﻋﻮاﻣﻞ ﻣﺆﺛﺮ ﺑﺮ ﺳﯿﻞ ﺧﯿﺰي ﻧﻈﯿﺮ ﺑﺎرش ﺑﺎران در دوره ﺑﺎزﮔﺸﺖ ﻫﺎي ﻣﺨﺘﻠﻒ، ﻃﻮل ﺟﺮﯾﺎن، درﺻﺪ ﺷــﯿﺐ، ﮐﺎرﺑﺮي اراﺿــﯽ، ﮔﺮوه ﻫﯿﺪروﻟﻮژي ﺧﺎك، ﻣﻘﺎدﯾﺮ CN و زﻣﺎنﺗﻤﺮﮐﺰ ﺷــﻨﺎﺳــﺎﯾﯽ و ﺳــﭙﺲ ﺑﺎ اﺳــﺘﻔﺎده از ﺗﻠﻔﯿﻖ ﻧﺮم اﻓﺰار ArcGIS و ﻣﺪل ModClark، ﭘﺘﺎﻧﺴﯿﻞ ﺗﻮﻟﯿﺪ رواﻧﺎب در ﺣﻮﺿﻪ ﺗﺎﻻر در ﭘﻨﺞ ﻃﺒﻘﻪ ﺧﯿﻠﯽ ﮐﻢ، ﮐﻢ، ﻣﺘﻮﺳﻂ، زﯾﺎد و ﺧﯿﻠﯽ زﯾﺎد در ﺳﻪ دوره ﺑﺎزﮔ ﺸﺖ 50 ،25 و 100 ﺳﺎل ﺗﻬﯿﻪ ﺷﺪ. ﻫﻤﭽﻨﯿﻦ ﺑﺮا ﺳﺎس ﻧﺘﺎﯾﺞ ﺑﺪ ﺳﺖ آﻣﺪه ﺳﻬﻢ زﯾﺮﺣﻮ ﺿﻪ ﻫﺎ در ﭘﺘﺎﻧ ﺴﯿﻞ ﺳﯿﻞ ﺧﯿﺰي ﮐﻞﺣﻮ ﺿﻪ ﺗﻨﻬﺎ ﺗﺤﺖ ﺗﺄﺛﯿﺮ ﻣ ﺴﺎﺣﺖ آﻧﻬﺎ ﻧﯿ ﺴﺖ و ﻋﻮاﻣﻠﯽ ﭼﻮن ﻣﻮﻗﻌﯿﺖ ﻣﮑﺎﻧﯽ زﯾﺮ ﺣﻮ ﺿﻪ ﻫﺎ و روﻧﺪﯾﺎﺑﯽ ﺳﯿﻞ در رودﺧﺎﻧﻪ اﺻﻠﯽ ﻧﯿﺰ در رژﯾﻢ ﺳﯿﻼﺑﯽ ﺣﻮﺿﻪ ﺗﺄﺛﯿﺮ ﻗﺎﺑﻞ ﺗﻮﺟﻬﯽ دارﻧﺪ. ﺑﻪ ﻫﻤﯿﻦ دﻟﯿﻞ ﺑﺮاﺳﺎس ﻧﻘﺸﻪ ﻫﺎي ﭘﺘﺎﻧﺴﯿﻞ ﺗﻮﻟﯿﺪ رواﻧﺎب در دوره ﺑﺎزﮔ ﺸﺖ ﻫﺎي 50 ،25 و 100 ﺳﺎﻟﻪ، ﭘﺘﺎﻧ ﺴﯿﻞ ﺗﻮﻟﯿﺪ رواﻧﺎب، از ﭘﺎﯾﯿﻦ د ﺳﺖ ﺑﻪ ﺳﻤﺖ ﺑﺎﻻد ﺳﺖ ﺣﻮ ﺿﻪ؛ اﻓﺰاﯾﺶ و زﯾﺮﺣﻮزه ﭼﺎ ﺷﻢ واﻗﻊ در ﺟﻨﻮب ﺷﺮﻗﯽ ﺣﻮ ﺿﻪ ﺑﺪﻟﯿﻞ ﺑﺎرش ﻫﺎي ﺳﯿﻼﺑﯽ، ﺷﯿﺐ ﺗﻨﺪ و ﺑﺎﻻﯾﻮدن ﻣﻘﺎدﯾﺮ CN ﺑﻪ ﻋﻨﻮان ﻣﺆﺛﺮﺗﺮﯾﻦ واﺣﺪ در ﭘﺘﺎﻧﺴﯿﻞ ﺳﯿﻞﺧﯿﺰي ﮐﻞ ﺣﻮﺿﻪ ﺗﺎﻻر- ﺷﯿﺮﮔﺎه ﻣﺤﺴﻮب ﻣﯽ ﺷﻮد

Prioritization of sub-watersheds and different areas has an important effect in watershed management. The purpose of prioritization of sub-watersheds is to provide a pattern for control and decrease flood hazards and evaluating the role of each sub-watershed in peak discharge of outlet flood hydrograph. In this study, Talar watershed was selected as study area, because of several floods was occurred in it and then factors affecting floods like rainfall hyetograph for different return periods, flow length, slope percentage, land use, soil hydrological group, amounts of CN and time of concentration were recognized. By combining ArcGIS software and ModClark hydrological model, the potential of flooding in Talar watershed classified into five classes: Very Low, Low, Medium, High and Very High within three return periods of 25, 50 and 100 years. The results showed that the contribution of sub-watersheds in flooding potential will be not only affected by its area but also the location of each sub-watershed and flood routing in main reach have remarkable effect on flooding regime of the watershed. Runoff production potential maps indicate that runoff production potential from downstream to upstream of the watershed is increasing and Chashm sub-watershed in Southeast of the watershed is considered as the most effective area and unit in flooding of the whole watershed because of heavy rainfall, high slope and large curve number (CN).