گزارش فني: بررسي و شناخت ويژگي هاي فرسايش و ليتولوژي مسير حاشيه رودخانه ها و مسيل هاي منطقه سيستان

Studying and Recognition of lithology and Erosion Rivers in Sistan region

ﻫﺪف از اﺟﺮاي اﯾﻦ ﭘﮋوﻫﺶ، ﺷﻨﺎﺧﺖ وﯾﮋﮔﯽ ﻫﺎي ﻓﺮﺳﺎﯾﺶ و ﻟﯿﺘﻮﻟﻮژي ﻣﺴﯿﺮ ﺣﺎﺷﯿﻪ رودﺧﺎﻧﻪ ﻫﺎ و ﻣﺴﯿﻞ ﻫﺎي ﻣﻨﻄﻘﻪ ﺳﯿﺴﺘﺎن ﺑﻮد. ﺑﺪﯾﻦ ﻣﻨﻈﻮر، وﺿﻌﯿﺖ رودﺧﺎﻧﻪ ﻫﺎي ﻣﻨﻄﻘﻪ ﺑﺮ اﺳﺎس ﺣﻮزه ﻫﺎي آﺑﺨﯿﺰ ﻣﺸﺨﺺ و اﻗﺪام ﺑﻪ ﺟﻤﻊ آوري آﻣﺎر و اﻃﻼﻋﺎت، ﺗﻬﯿﻪ و رﻗﻮﻣﯽ ﺳﺎزي ﻧﻘﺸﻪ ﻫﺎي ﺗﻮﭘﻮﮔﺮاﻓﯽ 1:250000 ﺳﯿﺴﺘﺎن و اﺳﺘﺨﺮاج اﻃﻼﻋﺎت ﻣﮑﺎﻧﯽ و ﺗﻮﺻﯿﻔﯽ و ﻫﻤﭽﻨﯿﻦ، آﻣﺎر و اﻃﻼﻋﺎت ﻣﺮﺑﻮط ﺑﻪ اﻧﻮاع ﻓﺮﺳﺎﯾﺶ در رودﺧﺎﻧﻪ ﻫﺎ و ﻣﺴﯿﻞ ﻫﺎي اﺳﺘﺎن ﺑﺎ اﺳﺘﻔﺎده از داده ﻫﺎي ﻣﻮﺟﻮد در ﮔﺰارﺷﺎت ﻗﺎﺑﻞ دﺳﺘﺮس و ﺑﺎزدﯾﺪﻫﺎي ﻣﯿﺪاﻧﯽ ﺟﻤﻊ آوري ﺷﺪ. اﻃﻼﻋﺎت ﻣﺮﺑﻮط ﺑﻪ اﻧﻮاع ﺳﺎزﻧﺪﻫﺎي زﻣﯿﻦ ﺷﻨﺎﺳﯽ ﻧﯿﺰ ﺑﺎ اﺳﺘﻔﺎده از ﻧﻘﺸﻪ ﻫﺎي 1:250000 ﺳﺎزﻣﺎن زﻣﯿﻦ ﺷﻨﺎﺳﯽ ﺟﻤﻊ آوري ﺷﺪ. ﻣﻨﺎﻃﻖ ﺣﺴﺎس ﺑﻪ ﻓﺮﺳﺎﯾﺶ در ﻃﻮل ﻣﺴﯿﺮ رودﺧﺎﻧﻪ ﺑﺎ اﺳﺘﻔﺎده از ﻧﻘﺸﻪ ﻫﺎي ﺣﺴﺎس ﺑﻪ ﻓﺮﺳﺎﯾﺶ و ﻧﻘﺸﻪ ﻫﺎي 1:250000 زﻣﯿﻦ ﺷﻨﺎﺳﯽ ، ﺣﺴﺎﺳﯿﺖ ﺳﺎزﻧﺪﻫﺎ ﻧﺴﺒﺖ ﺑﻪ ﻓﺮﺳﺎﯾﺶ در ﮐﻨﺎره آﺑﺮاﻫﻪ ﻫﺎ ارزﯾﺎﺑﯽ ﺷﺪ. از ﻣﻬﻤﺘﺮﯾﻦ ﻋﻮاﻣﻞ ﻣﻮﺛﺮ اﯾﺠﺎد ﻓﺮﺳﺎﯾﺶ در اﯾﻦ ﺣﻮﺿﻪ ﺷﺮاﯾﻂ زﻣﯿﻦ ﺷﻨﺎﺳﯽ آن ﻣﯽ ﺑﺎﺷﺪ. ﺑﺨﺶ ﻋﻤﺪه اي از اﺑﺘﺪاي ﺣﻮزه ﻫﺎي آﺑﺨﯿﺰ ﻣﻮرد ﺑﺮرﺳﯽ ﺑﻪوﺳﯿﻠﻪ ﻧﻬﺸﺘﻪﻫﺎي رﺳﻮﺑﯽ )ﻧﺎﭘﯿﻮﺳﺘﻪ( ﮐﻮاﺗﺮﻧﺮ ﭘﻮﺷﯿﺪه ﺷﺪه اﺳﺖ ﮐﻪ ﺣﺴﺎﺳﯿﺖ زﯾﺎدي ﻧﺴﺒﺖ ﺑﻪ ﻓﺮﺳﺎﯾﺶ آﺑﯽ دارد. ﻫﻤﭽﻨﯿﻦ، دﺷﺖ ﺳﯿﺴﺘﺎن ﭘﻮﺷﯿﺪه از رﺳﻮﺑﺎت درﯾﺎﭼﻪ اي ﻧﺌﻮژن و آﺑﺮﻓﺖ ﻫﺎي ﮐﻮاﺗﺮﻧﺮ اﺳﺖ. ﻃﺒﻘﻪ ﺑﻨﺪي ﺑﺴﺘﺮ رودﺧﺎﻧﻪ ﻫﺎي ﻣﻨﻄﻘﻪ ﺳﯿﺴﺘﺎن ﻧﺸﺎن ﻣﯽ دﻫﺪ ﮐﻪ ﺳﻨﮓ، ﻣﺨﺮوط اﻓﮑﻨﻪ و ﺳﺎﯾﺮ واﺣﺪﻫﺎ ﺑﻪ ﺗﺮﺗﯿﺐ 38/1 ،20/7 و 41/2 درﺻﺪ ﻃﻮل ﻣﺴﯿﺮ آنﻫﺎ را ﺗﺸﮑﯿﻞ ﻣﯽ دﻫﺪ. 7/2 درﺻﺪ رودﺧﺎﻧﻪ ﻫﺎي ﻣﻮرد ﺑﺮرﺳﯽ ﺗﺤﺖ ﺗﺎﺛﯿﺮ ﻓﺮﺳﺎﯾﺶ ﻗﺮار ﮔﺮﻓﺘﻪ ﮐﻪ ﺳﻬﻢ ﻧﻮع ﮐﻨﺎري و ﮐﻒ ﺑﺴﺘﺮ 85/1 و 14/9 درﺻﺪ ﺑﻮده اﺳﺖ.

Aim of this research was Studying and Recognition of lithology and Erosion Rivers in Sistan region. To done this research distinct situation of rivers according of basin and collected inform about basin of Sistan and review different parts of them such as type of erosion in river banks by using available reports and filed works. We have used available scale of 1:50,000, 1:250,000, Geologic maps, field observation and global positioning system (GPS). We found erodible area of river banks according to scale of 1:250,000 erodible Geologic maps. The data show that’s the main factor of cause to erosion is effect geologic conditions. The main parts of the basin covered with sediment of quaternary which is very sensitive to water erosion. The sistan rivers classification shows that stone, alluvium and other are 20.7, 38.1 and 41.2 percentage of rivers length, respectively. 7.2 percentages of area rivers occur erosion that bed and banks erosion are 85.1 and 14.9%, respectively.