Effects of Coastal River Dynamics on Shoreline Sedimentological Characteristics and Movement (Case Study: Western Makoran Coastal Plain, Iran)

Document Type : Full length article


1 Assistant Professor of Physical Geography, Department of Geography, University of Hormozgan

2 Assistant Professor of Physical Geography, Department of Physical Geography, University of Tarbiat Modares, Tehran, Iran

3 Professor of Physical Geography, Department of Physical Geography, University of Tehran, Tehran, Iran


More than half the world’s population lives in coastal regions (Bird, 2008).  The shorelines are unstable zone that comprises marine and terrestrial domains very sensitive to a variety of geological process; Waves and tides play a most important role in the coastal dynamics, and their mutual interaction accounts for redistribution of the sediment budget causing accumulation or erosion (Dabrio, 2000). The coastal ocean, where land, air and sea meet, is a region of very high physical energy and biological diversity that is heavily exploited by man (Murthy et al., 2002). Tidal flats are low-lying areas where alternately covered by water and exposed to the air each day (Gore, 2010). Analysis of forms and coastal conditions provides a valuable key for coastal management. Many studies have been conducted on the impact of waves on beach (Bagnold, 1939; Ross, 1955; Hayashi and Hattori, 1958). In a related research on western Mokran coastal plain, Shayan et Al. (2014) found that in terms of forming processes and according to the coastline curves and rivers' hydrodynamics, coastal sand masses were located by coastal waves. The aim of this study is to identify the effects of fluvial flows on sedimentological characteristics of shoreline in the western part of Mokran coastal plain, Iran.
The study area is located at 25o 31’- 27o 09’N, 56o 54’-59o 19’E, in western part of coastal plain of Mokran, south Iran in the north coast of Oman Sea and west to Strait of Hormoz. In general, the study area could be assumed a dry land with very low rain of windy, sand storm, torrent shower, thunder-storm, higher humidity and hazy down (Akbarian et al., 2006). From geological aspect, this area is affected by general construction of the Mokran (Makoran) region and mainly composed of shale, marl and sandstone layers.  
Materials and Method
The data of this research are including spatial distributions of tidal zones, velocities and directions of wind, fetch length, the morphologic and sedimentological characteristics including granulometeric and morphoscopic indicators. Geologic and topographic maps, satellite images, GPS, binocular microscope and computer software including ArcGIS and Gradistat also were used as the research tools. For sediment measurement studies, 8 samples were taken from shoreline. The samples were analyzed using ASTM standard sieves and Gradistat software from granulometery aspect. Morphoscopic indicators were investigated by 40X binocular microscope. After that, by using wind data, WRPlot View software and Molitor equations, wave characteristics were studied and the wave roses were plotted also.
Results and Discussion
It can be concluded that the processes of marine sediment transportation are in force across the range of this coastal zone. Waves and tides deliver sediment to the intertidal zone, so that wind is able to transport it landwards from the intertidal to the supratidal area (French, 2001).
Particle size windows (PSWs) are interpreted as reflecting different modes of sediment transport and deposition (Clarke et al., 2014). A beach can be composed of a wide variety of materials of many sizes and shapes (Dean and dalrymple, 2004). Based on sedimentological characteristics, tidal deposits are comprised of fine-grain to very fine sandy materials. In general, these grains are angular to sub-round and their surface textures are bright. The samples don’t have clay hunks but have small fragments of marine shells.
Waves are crucial in stirring up sand in the nearshore; variations in direction of wave approach, combined with irregularities in sea floor topography results in refraction or bending of wave crests and this initiates variations in energy levels received along a shoreline (kidd, 2001). On south coast, west and southwest waves are predominant from October till the end of June; In July, the percentage of southeast waves is considerably increased except of West Jask Cape. This situation continues till the end of September. Thus, the sediments brought by rivers, are drifted in different directions by waves along with coastline sharp curvatures.
The results of this present study show that coastal area sands were transported by the sea processes as a final stage. But morphometric indicators represent high impact of fluvial processes on coastal deposits. It can be concluded that sources of the analyzed sediments is adjacent to mouth of the rivers in the region; the transportation ability of sea processes is less than performance need to eliminate fluvial effects on coastal deposits  and sediments.


Main Subjects

احمدی، ح. (1377). ژئومورفولوژی کاربردی، ج2: بیابان، تهران: انتشارات دانشگاه تهران.
اختصاصی، م.ر. (1385). طرح کنترل کانون بحرانی سدیچ- هیمن، ج4: مطالعات فرسایش و رسوب، بندرعباس: ادارة کل منابع طبیعی استان هرمزگان.
اکبریان، م. (1393). تحلیل مورفوژنژ توده‏های ماسه‏ای جلگة ساحلی و تغییرات زمانی آنها (نمونة موردی: ساحل غربی مکران)، رسالة دکتری جغرافیای طبیعی ژئومورفولوژی، دانشگاه تربیت مدرس، 168ص.
بِرد، ا. (1392). ژئومورفولوژی ساحلی، ترجمة مجتبی یمانی و وحید محمدنژاد، تهران: انتشارات دانشگاه تهران.
چورلی، ریچارد جی. (1379). ژئومورفولوژی، ترجمة احمد معتمد، ج3: فرایندهای دامنه‏ای، آبراهه‏ای، ساحلی، و بادی، تهران: سمت.
سولزبی، ر. (1381). دینامیک ماسه‏های دریایی، ترجمة سیدعلی آزرمسا، تهران: دانشگاه تربیت مدرس.
شایان، س.؛ اکبریان، م.؛ یمانی، م.؛ شریفی‏کیا، م. و مقصودی، م. (1393). هیدرودینامیک دریا و تأثیر آن در تشکیل توده‏های ماسه‏ای ساحلی، مطالعة موردی: سواحل غربی مکران، پژوهش‎‏های ژئومورفولوژی کمّی، 2(4): 86ـ104.
علائی طالقانی، م. (1382). ژئومورفولوژی ایران، تهران: نشر قومس.
کوک، آر.یو. و دورنکمپ، جِی. سی. (1378). ژئومورفولوژی و مدیریت محیط، ج2، ترجمة شاهپور گودرزی‏نژاد، تهران: سمت.
لئو، زو. (جیو) (1390). انتقال رسوب، ترجمة وحید چگینی، تهران: مؤسسة ملی اقیانوس‏شناسی.
محمودی، ش. (1384). بررسی تغییرات طبیعی تپه‏های ماسه‏ای شرق جاسک در بازة زمانی 1369ـ1383، پایان‏نامة کارشناسی ارشد، گروه جغرافیا، دانشگاه اصفهان.
موسوی حرمی، ر. (1374). رسوب‏شناسی، چ 4، مشهد: انتشارات آستان قدس رضوی.
مهندسین مشاور سازهپردازان ایران (1386). مطالعات طرح مدیریت یکپارچة مناطق ساحلی ایران، سازمان بنادر و دریانوردی.
نگارش، ح. (1371). بررسی تحول ژئومورفولوژیکی بخشی از ناحیة ساحلی (از رمین تا باهوکلات)، دانشگاه تربیت مدرس.
 نوحه‏گر، ا. و حسین‏زاده، م.م. (1390). دینامیک دریا و عوامل مؤثر بر نوسانات تراز دریا در تحول قاعدة دلتاهای شمال تنگة هرمز، مجلة جغرافیا و برنامه‏ریزی محیطی، 22(43): 125ـ142.
نوحه‏گر، ا. و یمانی، م. (1385). ژئومورفولوژی ساحل شرقی تنگة هرمز با تأکید بر فرسایش بادی، هرمزگان: انتشارات دانشگاه هرمزگان.
یمانی، م. (1378). اثر حرکات آب دریای عمان در تشکیل و تکامل تالاب‏های جزر و مدی، پژوهش‏های جغرافیایی، 37: 19ـ34
یمانی، م. و فخری، س. (1391). بررسی عوامل مؤثر در تغییرات الگوی رودخانة جگین در جلگة ساحلی مکران، فصلنامة جغرافیا،  10(34): 141ـ 159.
Ahmadi, H. (1998). Applied Geomorphology, Vol. 2, Tehran University Press.
Akbarian, M. (2014). Analysis of Coastal plain Sand Masses Morphogenesis and their temporal variations (Case study: Western coast of Makran), Ph.D thesis, Supervisor: Dr. Siavosh Shayan, Dr. Mojtaba Yamani, Tarbiat Modares University, Iran.
Alaei Taleghani, M. (2003). Geomorphology of Iran, Tehran: Ghomes publishing.
Bagnold, R.A. (1939). Interim report on wave pressure research, Journal Inst. Civil Engr., 12: 201-226.
Bird, E. (2008). Coastal Geomorphology An Introduction, translated by Yamani, M., Mohammadnejsd, V., Tehran University Press.
Boggs, S. (2012). Principles of Sedimentology and Stratigraphy (5th edition), Prentice Hall, New Jersey, p. 60.
Chorley, Richard J. (2000). Geomorphology Volume 3 (Processes of Range, Rivers, Coastal and Wind), Translated by Motamed, A., Side Publishing, 455 p.
Clarke, D.W.; Boyle, J.f.; Chiverrell, R.C.; Lario, J. and Plater, A.J. (2014). A sediment record of barrier estuary behavior at the mesoscale: Interpreting high-resolution particle size analysis, Geomorphology,  221: 51-68.
Cook, R.U. and Doornkamp, J.C. (1999). Geomorphology in Environmental Management, Volume II, Translated by Goodarzinabad, S., Samt Publishing, 356 p.
Dabrio, C.J. (2000). Coastal Sedimentary Environment and Sea level Change, 10 Congresso sobre de Portugal.
Daidu, F. (2013). Classifications, sedimentary features and facies associations of tidal flats, Journal of Palaeogeography, 2(1): 66-80.
Davis, R.A. (1985). Coastal Sedimentary Environments (2nd edition), Springer-Verlag, New York, p. 716
Dean, R.G. and Dalrymple, R.A. (2004). Coastal processes with engineering applications, Cambridge University Press, United Kingdom, 489p.
Eisma,  D. (1998). Intertidal Deposits: River Mouths, Tidal Flats, and Coastal Lagoons, CRC Press, New York, p. 525.
Ekhtesasi, M.R. (2006). Study of Wind Erosion control of Sdych-Heyman critical area, Vol. 4, Erosion and Sedimentation studies.
French, P.W. (2001). Coastal Defences, processes, problems and solutions, Routledge Press, 385p.
Gore, P.J. (2010). Depositional Sedimentary Environments, Georgia Perimeter College Clarkston, Ga 30021, P.131-144.
Hayashi, T. and Hattori, M. (1958). Pressure of the breaker against vertical wall, Coastal Engineering in Japan, Vol.1.
Jones, A. (2005). Perth Community Risk Report, Chapter 7: Potential Coastal Erosion of the Swam Coastal plain due to long term Sea Level Rise, Geoscience Australia, http://www.ga.gov.au/webtemp/image_cache/GA6535.pdf
Kidd, R. (2001). Coastal Done Management, A Manual of Coastal Dune Management and Rehabilitation Techniques, NSW Department of Land and Water Conservation, 96p.
Kidson, C. (1960). The shingle complexes of Bridgwater Bay, Transactions of the Institute of British Geographers, 28: 75-87.
Leo, Z. (2011). Sediment transport, Translated by Chegini, V., Tehran: National Oceanographic Institute.
Luo, J.; Li, M.; Sun, Z. and O'Connor, B.A. (2013). Numerical modeling of hydrodynamics and sand transport in the tide-dominated coastal-to-estuarine region, Marine Geology, 342: 14-27.
Mahmoodi, S. (2005). Evaluation of dunes’ natural changes in Eastern Jask County in the period 1383-1369, Master thesis under supervision of Dr Mohammad Ramesht, Department of Geography, University of Isfahan.
Moosavi Harami, R. (1995). Sedimentology, Vol. IV, Mashhad: Astan Quds Razavi Publishing House.
Murthy, C.R.; Sinha, P.C. and Rao, Y.R. (2002). Modeling and Monitoring of Coastal Marine Processes, Springer, 249p.
Nohagar, A. and Yamani, M. (2006). Geomorphology of the East Coast of Hormoz Strait with Emphasis on Wind Erosion, Hormozgan University Press.
Nohegar, A. and Hosainzade, M.M. (2011). Sea Dynamics and the Factors affecting Sea level Fluctuations the Evolutions of the Deltas base in northern Strait of Hormuz, Geography  and Evvironmental Planning (University of Isfahan), Fall1, 22(43): 125- 142.
Phillips, J.D. and  Slattery, M. (2006). Downstream trends in discharge, slope, and stream power in a lower coastal plain river, Journal of Hydrology, 334(1-2): 290-303.
Reading, H.G. (1996). Sedimentary Environments: Processes, Facies, and Stratigraphy, John Wiley & Sons, New York, p. 688.
Rijn, Leo C. van. (2013). Erosion Of Coastal Dunes Due To Storms, www.leovanrijn-sediment.com
Ross, C.W. (1955). Laboratory study of shock pressurs of breaking wave, Beach Erosion Board Tech. Memo. No.59.
Sazehpardazan Iran Consulting Engineers Co (2007). Study on Integrated Coastal Zone Management Plan, Ports and Maritime Organization.
Shayan, S.; Akbarian, M.; Yamani, M.; Sharifikia, M. and Maghsoudi, M. (2014). Affect of Sea Hydrodynamic on Coastal Sand Masses Formation C,ase study: Western Makran Coastal Palin, Journal of Quantative Geomorphological Researches, 2(4): 86-104.
Sulzeby, R. (2002). Dynamics of Sea Sands, Translation by Azarmsa, S.A., Tehran: Tarbiat Modares University.
Yamani, M. (1995). The effect of water movement in the Sea of Oman on the development of tidal wetlands, Geographical researches, 37: 19-34.
Yamani, M. and Fakhri, S. (2012). Investigating the Factors Affecting the Patterns of the Jegin River in the Makran Coastal Plain, Geography Quarterly, 10(34): 141-159.