پیوندهای مفید
اخبار و اعلانات
آمار
| تعداد نشریات | 158 |
| تعداد شماره‌ها | 6,228 |
| تعداد مقالات | 67,750 |
| تعداد مشاهده مقاله | 115,085,323 |
| تعداد دریافت فایل اصل مقاله | 89,823,845 |
تأثیر جریان شکافنده بر دانه‌بندی رسوبات بستر دریا | ||
| فیزیک زمین و فضا | ||
| مقاله 7، دوره 49، شماره 1، خرداد 1402، صفحه 119-135 اصل مقاله (1.55 M) | ||
| نوع مقاله: مقاله پژوهشی | ||
| شناسه دیجیتال (DOI): 10.22059/jesphys.2023.336922.1007396 | ||
| نویسندگان | ||
| فاطمه دهباشی1؛ سید علی آزرم سا* 2 | ||
| 1گروه فیزیک دریا، دانشکده علوم دریایی، دانشگاه تربیت مدرس، نور، ایران. رایانامه: fatemeh.dehbashi@modares.ac.ir | ||
| 2نویسنده مسئول، گروه فیزیک دریا، دانشکده علوم دریایی، دانشگاه تربیت مدرس، نور، ایران. رایانامه: azarmsaa@modares.ac.ir | ||
| چکیده | ||
| جریان شکافنده از جمله مهم‌ترین پدیده‌های مطرح در مناطق ساحلی است که علاوه بر تأثیرات فیزیکی قابل‌توجه در منطقه ساحلی، عامل بخش قابل‌توجهی از مرگ‌ومیرها و حوادث دریایی است. به همین دلیل این جریان توسط گروهی از محققان بین‌المللی از جنبه‌های مختلف موردتوجه قرار گرفته است. در این تحقیق سعی شده است با نمونه‌برداری از رسوبات کف کانال جریان شکافنده و محیط اطراف آن در سواحل دریای خزر، تأثیر جریان شکافنده بر دانه‌بندی این رسوبات مشخص شود. نمونه‌برداری به‌صورت ماهانه در دو فصل زمستان و بهار انجام شد. برای مقایسه ویژگی‌های رسوب در کانال ریپ و پشته‌های اطراف آن از آزمون تی تست غیر زوجی استفاده شد و اختلاف معنی داری در سطح 95% مشاهده شد. نتایج گرانولومتری نشان داد که تفکیک داده ها به دو فصل زمستان و بهار نشان‌دهنده‌ی تفاوت معنی‌دار قطر میانه، میانگین اندازه ذرات و چولگی توزیع ذرات رسوب در کانال جریان شکافنده نسبت به محیط اطراف آن در فصل بهار شد. در فصل زمستان احتمالاً به دلیل آشفتگی آب‌وهوا و تلاطم در جریانات دریایی و امواج مرتفع حاصل از وزش بادهای شدید تفاوت مقدار این پارامترها در داخل کانال شکافنده و محیط اطراف آن معنی‌دار نبوده است. | ||
| کلیدواژه‌ها | ||
| جریان شکافنده؛ کانال ریپ؛ گرانولومتری؛ منطقه ساحلی؛ دریای خزر | ||
| عنوان مقاله [English] | ||
| Effect of Rip Currents on granulometry of sea bed sediments | ||
| نویسندگان [English] | ||
| Fatemeh Dehbashi1؛ Seyed Ali Azarmsa2 | ||
| 1Department of Marine Physics, Faculty of Marine Sciences, Tarbiat Modares University, Noor, Iran. E-mail: fatemeh.dehbashi@modares.ac.ir | ||
| 2Corresponding Author, Department of Marine Physics, Faculty of Marine Sciences, Tarbiat Modares University, Noor, Iran. E-mail: azarmsaa@modares.ac.ir | ||
| چکیده [English] | ||
| Rip current is one of the most important phenomena in coastal areas. Due to the importance of rip currents, which are directly related to human lives, they have been studied and evaluated from different approaches. This research aimed to determine rip currents' effect on the sediments' granulometry through sampling of the sediments in the rip channel and its surrounding area on the Caspian Sea coast. In this study, one station was selected in Noor city, Mazandaran province. Various factors such as lack of private property, easy access, lack of human manipulation, and knowledge of drowning rescuers about the location of the drowned were considered in the selection of the station. Then, in two seasons, winter (December and March) and spring (May and June), with the help of lifeguards and existing signs, the location of the rip canal was identified in the station and at least three sediment samples were taken from the channel and three samples from the environment around the channel using Grab. In addition, the water depths were estimated in the sediment sampling points using Echo sounder. The sediment samples were transferred to the laboratory and sediment particles were separated based on grain size using a shaker and multiple sieves (with a network mesh of 30, 50, 60, 80, 100, 140, 200, and 230). The data obtained from the shaker were entered into the excel page of GRADISTAT software and the characteristics of sediment samples including mean diameter (D50), mean degree of sorting, skewness, and kurtosis were calculated by Folk and Ward method. All sediment particle characteristics were compared between the rip channels and surrounding areas using an unpaired t-test. The results showed that among the sedimentation characteristics, no significant difference was observed between the channel and surrounding areas in the degree of sorting and kurtosis neither in the winter nor in the spring. In addition, the results of granulometry showed that D50, mean particle size, and skewness of grain distribution of sediment particles were significantly different between the rip channel and the surrounding areas in the spring. The highest amount of D50 (with an average of 185.8 mm), mean (with an average of 202.7 mm) and skewness (0.48) of sediment particles were observed in the rip channel. These significant differences in particle characteristics were not observed in the winter samples probably due to the turbulent weather and sea currents. In addition, the average water depth of the rip channel was obtained at ca. 120 cm, while the average water depth of surrounding areas was estimated at ca. 85 cm. Therefore, we can state that some of the channel sediments have been removed by water flow in the channel. The higher energy and velocity of the flow in the channel than the surrounding environment has caused the transfer of sediments. On the other hand, sediment transport is directly related to other parameters such as sediment grain size. The present study showed that rip channels have sediments with significantly different characteristics than the surrounding sediments. The higher flow rate in the rip channel probably causes the removal of some fine-grained sediments and is not able to remove coarse-grained sediments. Removal of fine-grained sediments causes a change in the texture of the remaining sediments towards larger grains and these changes have caused a significant granulometric change between the rip channel and the surrounding environment, especially in the spring. | ||
| کلیدواژه‌ها [English] | ||
| Rip Current, Rip Channel, Granulometry, Coastal area, Caspian Sea | ||
| مراجع | ||
|
Aagaard, T., Greenwood, B., & Nielsen, J. (1997). Mean currents and sediment transport in a rip channel.Marine Geology, 140(1-2), 25-45. Azarmsa, S. A. (2002). Dynamics of marine sands, Tarbiat Modares University Publications, 266 p. Azarmsa, S. A. (2019). An Introduction to Wind Induced Water Waves, Tarbiat Modares University Press, 348 p. Bong, T., Son, Y., & Kim, K.-S. (2019). Experimental modeling of suspended sediment transport considering the flow rate and grain size. Journal of Coastal Research, 35(3), 637–647. Brannstrom, C., Trimble, S., Santos, A., Brown, H. L., & Houser, C. (2014). Perception of the rip current hazard on Galveston Island and North Padre Island, Texas, USA. Nat. Hazards, 72, 1123-1138. Brander, R.W. (1999a). Sediment transport in low-energy rip current systems. Journal of coastal research, 839-849. Brander, R.W. (1999b). Field observations on the morphodynamic evolution of a low-energy rip current system. Marine geology, 157(3-4), 199-217. Brighton, B., Sherker, S., Brander, R., Thompson, M., & Bradstreet, A. (2013). Rip current related drowning deaths and rescues in Australia 2004–2011. Nat. Hazards Earth Syst. Sci., 13, 1069-1075. Castelle, B., Scott, T., Brander, R. W., & McCarroll, R. J. (2016). Rip current types, circulation and hazard. Earth-Sci. Rev., 163, 1-21. Dong, P., Chen, Y., & Chen, S. (2015). Sediment Size Effects on Rip Channel Dynamics. Coastal Engineering, 99, 124-135. Folk, R.L., & Ward, W.C. (1957). Brazos River bar: a study in the Significance of Grain Size Parameters. Journal of Sedimentary Petrology, 27, 3-26. Gallop, S.L., Woodward, E., Brander, R.W. & Pitman, S.J. (2016). Perceptions of rip current myths from the central south coast of England. Ocean & Coastal Management, 119, 14-20. Haidari Nasheli, Z., & Azarmsa, S.A. (2006). Potential occurrence and effects of rip current on the coasts of Mazandaran province, Master’s thesis, Tarbiat modares university. Kabiri-Samani, A.R., Aghaee-Tarazjani, J., Borghei, S.M., & Jeng, D.S. (2011). Application of Neural Networks and Fuzzy Logic Models to Longshore Sediment Transport, Applied Soft Computing, 11(2), 2880-2887. Kumar, S.V.V., & Prassad, K.V.S.R. (2014). Rip current-related fatalities in India: a new predictive risk scale for forecasting rip currents. Natural Hazards, 70(1), 313-335. Kunte, P.D. (2008). Sediment Concentration and Bed Form Structures of Gulf of Cambay from Remote Sensing. International Journal of Remote Sensing, 29(8), 2169-2182. Linares, A., Wu, C.H., Bechle, A.J., Anderson, E.J., & Kristovich, D.A.R. (2019). Unexpected rip currents induced by a meteotsunami. Scientific Reports, 9(1), 2105. Doi:org/10.1038/s41598-019-38716-2. MacMahan, J.H., Thornton, E.B., Stanton, T.P., & Reniers, A.J. (2005). RIPEX: Observations of a rip current system. Marine Geology, 218(1-4), 113-134. McLaren, P., 1981, An Introduction of Trends in Grain Size Measures. Journal of Sedimentary Petrology. 51(2), 611-624. Muralidharan, J., Ganesh Kumar, B., & Kunte, P.D. (2015). Sediment Transport Study along Gulf of Kachchh – A Numerical and Geospatial approach. International Journal of Applied Engineering Research, 10(55), 4291-6. Poppe, L. J., Eliason, A. H., Fredericks, J. J., Rendigs, R. R., Blackwood, D., & Polloni, C. F., 2000, Grain-size Analysis of Marine Sediments: Methodology and Data Processing, US Geological survey open-file report, P. 358. Rudeh, H., Lorestani, Gh., Etemadi, F., Valikhani, S., 2014, Dynamic Simulation of Waves and Sand Transport on the Coast of the Caspian Sea. Quantitative geomorphological Researches, 2(2), 1-18. Sharaki, M., & Azarmsa, S. A. (2019). A Field Study of Breaking Zone Width, Breaker Height, and Number of Breakings in the East Coast of Noor. Marine Eng., 15(13), 113-120. Shushtarizadeh Naseri, A., & Tavakoli, M. (2013). Rip Current, Recognition, Issues and Approaches, Bandar, 203, 32-40. Short, A.D. (1985). Rip-current type, spacing and persistence, Narrabeen Beach, Australia. Marine geology, 65(1-2), 47-71. Siuf Jahromi M., & Ghaderi D. (2014). Rip current in the beach and its hazards. First National Conference in Marine Sciences, Bandarabbas, 1-13. Srivastava, A.K., Ingle, P.S., Lunge, H.S., & Khare, N. (2012). Grain-size characteristics of deposits derived from different glacigenic environments of the Schirmacher Oasis, East Antarctica. Geologos, 18(4), 251-266. Thornton, E.B., MacMahan, J., & Sallenger Jr, A.H. (2007). Rip currents, mega-cusps, and eroding dunes. Marine geology, 240(1-4), 151-167. Thorpe, A., Miles, J., Masselink, G., Russell, P., Scott, T., & Austin, M. (2013). Suspended Sediment Transport in Rip Currents on a Macrotidal Beach. Journal of Coastal Research, 65, 1880-1885. Valipour, A., Karimi Khaniki, A., & Bidokhti, A.A. (2014). Investigating the reactions of rip current pattern and sediment transport in rip channel against changes of bed parameters using numerical simulations. Indian Journal of Geo-Marine Sciences, 43(5), 831-840. Woodward, E.M. (2015), Rip currents in the UK: incident analysis, public awareness and education. School of Marine Sciences and Engineering, Faculty of Science and Environment, UK, PhD Thesis. Zhang, X., Ji, Y., Yang, Z., Wang, Z., Liu, D., & Jia, P. (2016). End member inversion of surface sediment grain size in the South Yellow Sea and its implications for dynamic sedimentary environments. Science China Earth Sciences, 59(2), 258-267. Zare Chahuki, M.A. (2010), Data Analysis in Natural Resources Research using SPSS Software, Jehad-Daneshgahi, Tehran University Press, 310 p. | ||
|
آمار تعداد مشاهده مقاله: 289 تعداد دریافت فایل اصل مقاله: 206 |
||