تحليل ويژگي هاي بافتي رسوبات رودخانه سرباز و برآورد بار رسوبي رودخانه در حوضه آبخير سد پيشين، شرق استان سيستان و بلوچستان

Analysis of Histological features of Sarbaz River sediments and Estimation of river sediment load in Pishin dam Drainage basin, east of Sistan and Baluchestan province

رﺳﻮﺑﺎت رودﺧﺎﻧﻪاي از اﺻﻠﯽﺗﺮﯾﻦ اﺟﺰاي اﮐﻮﺳﯿﺴﺘﻢﻫﺎي آﺑﯽ ﻫﺴﺘﻨﺪ ﮐﻪ ﻧﻘﺶ اﺳﺎﺳﯽ در ﭼﺮﺧﻪ ﻋﻨﺎﺻﺮ ﻏﺬاﯾﯽ و ﻫﻤﭽﻨﯿﻦ اﻧﺘﻘﺎل آﻻﯾﻨﺪه ﻫﺎ در ﺳﯿﺴﺘﻢﻫﺎي آﺑﯽ ﯾﺮ ﻋﻬﺪه دارﻧﺪ. ﻟﺬا در اﯾﻦ ﭘﮋوﻫﺶ، وﯾﮋﮔﯽﻫﺎي ﺑﺎﻓﺘﯽ رﺳﻮﺑﺎت رودﺧﺎﻧﻪ ﺳﺮﺑﺎز و ﺑﺮآورد ﺑﺎر رﺳﻮﺑﯽ رودﺧﺎﻧﻪ در ﺣﻮﺿﻪ آﺑﺨﯿﺮ ﺳﺪ ﭘﯿﺸﯿﻦ، ﺷﺮق اﺳﺘﺎن ﺳﯿﺴﺘﺎن و ﺑﻠﻮﭼﺴﺘﺎن، ﻣﻮرد ﻣﻄﺎﻟﻌﻪ ﻗﺮار ﮔﺮﻓﺘﻪ اﺳﺖ. ﺟﻬﺖ رﺳﻮب ﺳﻨﺠﯽ، در اﯾﻦ ﺗﺤﻘﯿﻖ از روش ﺑﺮونﯾﺎﺑﯽ ﯾﺎ ﻣﻨﺤﻨﯽ ﺳﻨﺠﻪ رﺳﻮب اﺳﺘﻔﺎده ﮔﺮدﯾﺪه اﺳﺖ. ﺑﺮ اﺳﺎس داده ﻫﺎي ﻣﺮﺑﻮط ﺑﻪ دﺑﯽ ﺟﺮﯾﺎن و دﺑﯽ رﺳﻮب راﺑﻄﻪ ﺑﯿﻦ آﻧﻬﺎ ﺑﺮاي رودﺧﺎﻧﻪ ﺳﺮﺑﺎز ﺑﻪ ﺻﻮرت )1/939 Qs=22/89 * QW( ﻣﺤﺎﺳﺒﻪ ﮔﺮدﯾﺪه اﺳﺖ. ﻣﯿﺎﻧﮕﯿﻦ ﺳﺎﻻﻧﻪ ﺑﺎر رﺳﻮﺑﯽ در ﻣﺤﻞ ﺑﺎﻟﻎ ﺑﺮ 425021 ﺗﻦ ﺑﺎر ﻣﻌﻠﻖ و ﺑﯿﻦ 42500 ﺗﺎ 85000 ﺗﻦ ﺑﺎر ﺑﺴﺘﺮ در ﺳﺎل ﺑﻪ دﺳﺖ آﻣﺪه اﺳﺖ. ﻫﻤﭽﻨﯿﻦ ﺳﺎﯾﺮ ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﺗﻐﯿﯿﺮ ﻣﯿﺎﻧﮕﯿﻦ اﻧﺪازه ذرات و ﺟﻮرﺷﺪﮔﯽ رﺳﻮﺑﺎت ﺑﻪ ﺻﻮرت اﻓﺰاﯾﺶ ﻧﻤﺎﺋﯽ ﻏﯿﺮ ﭘﯿﻮﺳﺘﻪ از ﻣﺤﻞ ورود ﺷﺎﺧﻪ ﻫﺎي ﻓﺮﻋﯽ ﺗﺎ ﻣﺼﺐ رودﺧﺎﻧﻪ، ﺑﻪ ﺧﻮﺑﯽ ﻧﻘﺶ ﺷﺎﺧﻪ ﻫﺎي ﻓﺮﻋﯽ ﺗﻐﺬﯾﻪ ﮐﻨﻨﺪه را در وﺿﻌﯿﺖ رﺳﻮبﺷﻨﺎﺳﯽ ﺷﺎﺧﻪ اﺻﻠﯽ ﻧﺸﺎن ﻣﯽدﻫﺪ.

River sediments are the major component of the aquatic ecosystems and play an important role in the nutrients cycle and contaminants transformation in river systems. Therefore, in this study, Analysis of Histological features of Sarbaz River sediments and Estimation of river sediment load in Pishin dam Drainage basin, east of Sistan and Baluchestan province, has been studied. For sedimentation, in this study, extrapolation method or sediment measurement curve has been used. According to the relevant data to stream discharge and sediment discharge, their relationship is evaluated as (Qs=22/89 * QW 1/939). Annual average of sediment load in the river is obtained as 425021 ton of suspended load and 42500 to 85000 ton of bed load. Other results also showed that the change in mean particle size and sediment sorting in the form of a discontinuous exponential increase from the point of entry of tributaries to the estuary of the river, well shows the role of feeding tributaries in the sediment logical status of the main tributary.