پديد آورندگان :
حسين زاده, محمد مهدي دانشگاه شهيد بهشتي - دانشكده علوم زمين - گروه جغرافياي طبيعي , رستمي, ميلاد دانشگاه شهيد بهشتي - دانشكده علوم زمين - گروه جغرافياي طبيعي , اسماعيلي, رضا داﻧﺸﮕﺎه ﻣﺎزﻧﺪران - داﻧﺸﮑﺪه ﻋﻠﻮم اﻧﺴﺎﻧﯽ و اﺟﺘﻤﺎﻋﯽ - ﮔﺮوه ﺟﻐﺮاﻓﯿﺎ
كليدواژه :
رودﺧﺎﻧﻪ واز , ﺳﻨﮕﭽﯿﻦ ﮐﻨﺎره , ﺿﺮﯾﺐ ﭘﺎﯾﺪاري , ﻣﺪل ﻟﯿﻦ , ﻓﺮﺳﺎﯾﺶ ﮐﻨﺎرهاي
چكيده فارسي :
ﺗﻐﯿﯿﺮات ﻣﺠﺮاي رودﺧﺎﻧﻪ، ﻓﺮﺳﺎﯾﺶ ﮐﻨﺎرهاي و رﺳﻮﺑﮕﺬاري ﮐﻨﺎرهاي، ﻓﺮآﯾﻨﺪﻫﺎي ﻃﺒﯿﻌﯽ رودﺧﺎﻧﻪﻫﺎي آﺑﺮﻓﺘﯽ ﻫﺴﺘﻨﺪ ﮐﻪ ﺑﺎﻋﺚ ﺗﺨﺮﯾﺐ زﻣﯿﻦﻫﺎي ﮐﺸﺎورزي اﻃﺮاف و ﺧﺴﺎرت ﺑﻪ ﺗﺎﺳﯿﺴﺎت اﻧﺴﺎﻧﯽ اﻃﺮاف رودﺧﺎﻧﻪ ﻣﯽﺷﻮد. در اﯾﻦ ﭘﮋوﻫﺶ ﺑﺎ اﺳﺘﻔﺎده از ﻣﺪل ﺗﻨﺶ ﺑﺮﺷﯽ ﻟﯿﻦ ﻣﯿﺰان ﺿﺮﯾﺐ ﻧﺎﭘﺎﯾﺪاري ﮐﻨﺎره رودﺧﺎﻧﻪ واز در اﺳﺘﺎن ﻣﺎزﻧﺪران ﺑﺮرﺳﯽ ﺷﺪه اﺳﺖ. ﺑﺪﯾﻦ ﻣﻨﻈﻮر ﮐﻠﯿﻪ ﭘﺎراﻣﺘﺮﻫﺎي ﻣﻮرد ﻧﯿﺎز ﺑﺎ اﺳﺘﻔﺎده از ﻣﻄﺎﻟﻌﺎت ﻣﯿﺪاﻧﯽ، ﺗﺼﺎوﯾﺮ ﮔﻮﮔﻞ ارث و آزﻣﺎﯾﺶ داﻧﻪﺑﻨﺪي اﻧﺪازهﮔﯿﺮي ﺷﺪ. ﺑﺮاﺳﺎس ﻣﺪل ﻓﻮق ﻣﻘﺎﻃﻊ ﻧﺎﭘﺎﯾﺪار ﺷﻨﺎﺳﺎﯾﯽ ﺳﭙﺲ ﺑﺮاي ﻫﺮ ﯾﮏ از اﯾﻦ ﻣﻘﺎﻃﻊ، اﻧﺪازه ﭘﺎره ﺳﻨﮓ ﺟﻬﺖ ﺳﻨﮕﭽﯿﻨﯽ ﮐﻨﺎره رودﺧﺎﻧﻪ ﺑﻪ ﻋﻨﻮان راﻫﮑﺎر ﻣﺪﯾﺮﯾﺘﯽ ﺗﻌﯿﯿﻦ ﺷﺪه اﺳﺖ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﮐﻪ ﻣﻘﺎﻃﻊ 4 ،1 ،7 ،5 ،3 ،8 ،2 ،6 ﺑﻪ ﺗﺮﺗﯿﺐ داراي ﺑﯿﺸﺘﺮﯾﻦ ﺗﺎ ﮐﻤﺘﺮﯾﻦ ﺿﺮﯾﺐ ﭘﺎﯾﺪاري ﻫﺴﺘﻨﺪ. ﺑﺮ اﯾﻦ اﺳﺎس اﻧﺪازه ﭘﺎره ﺳﻨﮓ در آﺳﺘﺎﻧﻪ ﺣﺮﮐﺖ و ﭘﺎره ﺳﻨﮓ ﻣﻨﺎﺳﺐ ﺟﻬﺖ ﺳﻨﮕﭽﯿﻨﯽ ﮐﻨﺎره و ﺣﻔﺎﻇﺖ از ﮐﻨﺎره رودﺧﺎﻧﻪ ﻣﺘﻔﺎوت ﺧﻮاﻫﺪ ﺑﻮد. ﻫﻤﭽﻨﯿﻦ ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﺷﺮاﯾﻂ ﻫﺮ ﻣﻘﻄﻊ، ﺷﯿﺐ ﻣﻨﺎﺳﺐ ﮐﻨﺎره ﺟﻬﺖ ﻋﻤﻠﯿﺎت ﺳﻨﮕﭽﯿﻦ ﮐﺮدن ﻣﺘﻔﺎوت ﻣﯽﺑﺎﺷﺪ. ﮐﻪ در اﯾﻦ ﺑﺎزه از رودﺧﺎﻧﻪ واز ﻣﻘﻄﻊ ﺷﻤﺎره 1 ﺑﺰرﮔﺘﺮﯾﻦ ﭘﺎره ﺳﻨﮓ ﺑﺎ اﻧﺪازه 1/21 ﻣﺘﺮ در ﺷﯿﺐ 20 درﺟﻪ و ﭘﺎره ﺳﻨﮓ ﺑﺎ اﻧﺪازه 0/69 ﻣﺘﺮ در ﺷﯿﺐ 30 درﺟﻪ ﻣﻮرد ﻧﯿﺎز اﺳﺖ. ﻣﻘﻄﻊ ﺷﻤﺎره 6 ﮐﻮﭼﮑﺘﺮﯾﻦ ﭘﺎره ﺳﻨﮓ ﺑﺎ اﻧﺪازه 0/248 در ﺷﯿﺐ 20 درﺟﻪ و ﭘﺎره ﺳﻨﮓ ﺑﺎ اﻧﺪازه 0/115 ﻣﺘﺮ در ﺷﯿﺐ 30 درﺟﻪ ﻣﻮرد ﻧﯿﺎز اﺳﺖ.
چكيده لاتين :
IntroductionChanges in river channel, bank erosion and sedimentation are the natural processes in alluvial rivers which might destruct and damage surrounding human facilities and farms. Regarding this, the study of bank-river instability is done for engineering activities in order to form the necessary proceedings to stabilize the banks against erosion.Material and methodsIn this study using the Lin shear stress, the rate of instability coefficient has been investigated in the Vaz River in Mazandaran province. All the required parameters are assessed in geomorphology library using field surveys, google earth images and granometry. At first, a two-kilometer reach is determined and eight cross sections were chosen in this reach. After that, to riprap the instable bank bed slope, shear stress, bank angle, stability coefficient and effective rock size of the Vaz River is defined as the management strategy. Discussion and resultsAfter measuring the parameters affecting the shear stress index of river-banks in the Vaz River, the rate of bank stability, the rock size in the incipient motion and the effective rock size to riprap the river is estimated in two scenarios including 20° and 30° angles of slope. To determine the effective rock size the highest angle of repose and shields parameters are considered as 42 and 0.054, respectively. In phase two with hypothetical bank slope of 20° and 30°, the rock size in the sixth to ninth steps for different rock sizes are repeated constantly, since SF=1 was obtained. In this situation, the effective riprap rock size and the rock size in the incipient motion is estimated for the two suggested scenarios. Conclusions The results reveal that the sections 6, 2, 8, 3, 5, 7, 1, 4 have the most and least stability coefficients, respectively. Therefore, the suitable rock size to riprap the bank and protect the bank-river would be different from the size of rock in the incipient motion. Furthermore, considering the situation of each section, the suitable angle or the bank slope are different to riprap the bank. In the reach of the Vaz River in section 1 the coarsest required rock sizes are 1.21 m in 20° angle of slope and 0.69 m in a slope with 30° angle. In the section 6 the smallest required rock size is 0.248 m in 20° of slope and 0.115 m in 30 degree of slope.
