اثر حساسیت به فرسایش و کاربری‌ اراضی بر خصوصّیات مورفومتری رسوب بستر (مطالعه موردی: رودخانه وازرود)

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشکده منابع طبیعی و علوم دریایی دانشگاه تربیت مدرّس، نور، مازندران

2 دانشکده منابع طبیعی و علوم دریایی، دانشگاه تربیت مدرّس، نور، مازندران

چکیده

        بررسی عوامل مؤثر بر خصوصّیات مورفومتری رسوبات بستر رودخانه­ها می­تواند منجر به درک بهتر فرآیندهای رسوب­گذاری و حمل رسوب و طبعاً مدیریت کارآتر و استفاده بهینه از آنها شود. تحقیق حاضر با هدف بررسی اثرات تغییر حساسیت به فرسایش سازندها، کاربری اراضی و برداشت شن و ماسه بر خصوصّیات مورفومتری رسوبات بستر در مسیری به طول 30 کیلومتر از رودخانه وازرود در استان مازندران انجام گرفت. به­همین منظور تعداد 9 مقطع برای نمونه­برداری در این رودخانه به­گونه­ای تعیین شدند که بتوان این اثرات را بررسی کرد. نمونه رسوبات بستر در این مقاطع با شیوه ترکیبی برداشت و خصوصّیات مورفومتری شامل میانگین، جورشدگی، چولگی، کشیدگی، قطرهای ده، پنجاه و نود درصد، بافت، کرویت و گردشدگی با استفاده از روش الک کردن و نرم افزار GRADISTAT محاسبه گردید. نتایج حاصل از تحقیق نشان داد که تغییر حساسیت به فرسایش سازندها، کاربری مسکونی و برداشت شن و ماسه در این رودخانه روند تغییرات طبیعی پارامترهای اندازه رسوبات (میانگین، 105090d و بافت) و نیز گردشدگی رسوبات بستر رودخانه را تحت تأثیر قرار داده و در برخی مقاطع روند را معکوس نموده­اند.

کلیدواژه‌ها


عنوان مقاله [English]

Effects of Erosion Sensitivity and Different Land Uses on Morphometric Characteristics of Bed Sediments (Case Study: Vazrood River)

نویسندگان [English]

  • A Khaledi Darvishan 1
  • SHR Sadeghi 2
  • L Gholami 2
چکیده [English]

Study of effective factors on morphometric characteristics of bed sediments may lead to better understanding of sediment transportation and deposition processes and finally, their efficient control or optimal utilization. The present study was aimed to evaluate the effects of erosion sensitivity of formations, land use and sand and gravel mining on morphometric characteristics of bed sediments at a 30 km reach of VazroodRiver in Mazandaran Province, Iran. To achieve the study purposes, 9 sampling sections were selected so that the desired effects could be assessed. The bed sediments were then sampled using combining technique and the morphometric characteristics viz. mean, sorting, skewness, kurtosis, d10, d50, , d90, texture, sphericity and roundness were determined using sieving and GRADISTAT software. The results of the study revealed that erosion sensitivity of the formations, residential use and sand and gravel mining in the river all affected the natural trends of the sediments size parameters (mean, d10, d50 and d90 and sediment texture) as well as roundness, and reversed the trend in some sections.
 

کلیدواژه‌ها [English]

  • Bed sediment
  • Granolumetry
  • Mazandaran
  • Roundness
  • Sediment morphometry
  • Vazrood
خالقی پ، 1377. نیمرخ جنگل­های خزر، جنگل تحقیقاتی وازرود. انتشارات موسسه تحقیقات جنگل­ها و مراتع، تهران.
شفاعی بجستان م، 1373. هیدرولیک رسوب. انتشارات دانشگاه شهید چمران، اهواز.
Ahmad Bakri AG, Aminuddin, ABG, Nor Azazi Z, Zorkeflee AH and Chang CK, 2004. Determination of Manning’s flow resistance coefficient for rivers in Malaysia, Pp. 104-110. 1st International Conference on Managing Rivers in the 21st Century: Issues and Challenges, September 2004, Penang, Malaysia.
Blott SJ and Pye K, 2001. Gradistat: A grain size distribution and statistics package for the analysis of unconsolidated sediment. EarthSurfProcLand 10(26): 1237-1248.
Brown AV, Lyttle MM and Brow KB, 1998. Impacts of gravel bed streams. T Am Fish Soc 127(6): 979-994.
Clifford NJ, 2001. Conservation and the river channel environment, Pp. 68-104. In: Warren A and French JR. (eds). Habitat Conservation, John Wiley and Sons Ltd,  London.
Demir T, 2003. Downstream changes in bed material size and shape characteristics in a small upland stream, Cwm Treweryn, in South Wales, Pp. 33-47. Bulletin of Earth Sciences Application and Research Centre of Hacettepe University, Turkey.
Fripp JB and Diplas P, 1993. Surface sampling in gravel stream. J Hydraul Eng. ASCE 119 (4): 473-490.
Gomez B, 2001. Downstream mining in a rapidly aggrading gravel bed river. Water Resour Res 37 (6): 1813-1823.
Gordon E and Meentemeyer RK, 2006. Effects of dam operation and land use on stream channel morphology and riparian vegetation. Geomorphology 82: 412–429.
Healy T and Wo K, 2002. Sediment characteristics and bed level changes in relation to sand extraction and damming of a sand-gravel river: The Lower Waikato River, New Zealand. J Hydrol (NZ) 41(2): 175-196.
Heitmuller F and Hudson PF, 2009. Downstream trends in sediment size and composition of channel-bed, bar, and bank deposits related to hydrologic and lithologic controls in the Llano river watershed, central Texas, USA. Geomorphology 112: 246–260.
Kang RS and Marston RA, 2006. Geomorphic effects of rural-to-urban land use conversion on three streams in the Central Redbed Plains of Oklahoma. Geomorphology 79: 488–506.
Koche RC and Baker V, 1988. Paleoflood analysis using slack water deposits, Pp. 357-376. Flood Geomorphology. John Wiley and Sons Publications.
Krumbein WC, 1940. Flood gravel of San Gabriel Canyon, California. Geol Soc Am Bull 51: 639-676.
Lagasse PF, Simons DB and Winkley BR, 1980. Impact of gravel mining on river system stability. J Waterway, Part C 106(3): 389-404.
Lee H, Fu DT and Song M, 1993. Migration of rectangular mining pit composed of uniform sediments. J Hydraul Eng, ASCE 119(1): 64-80.
Leeder MR, 1988. Sedimentology: Process and Product, Fletcher & Son Ltd.
Lundekvam HE, Romstad E and Oygarden L, 2003. Agricultural policies in Norway and effects on soil erosion. Environ Sci & Policy 6:57–67.
Marstona RnA, Bravard JP and Greenc T, 2003. Impacts of reforestation and gravel mining on the MalnantRiver, Haute-Savoie, French Alps. Geomorphology 55: 65-74.
Mass-Plaa J, Montanerb J and Solab J, 1999. Groundwater resources and quality variations caused by gravel mining in coastal streams. J Hydrol 216:197-213.
Mosley MP and Tindale DS, 1985. Sediment variability and bed material sampling in gravel-bed rivers. Earth Surf Proc Land 10(5): 465-482.
Mueller EN, Francke T, Batalla RJ and Bronstert A, 2009. Modelling the effects of land-use change on runoff and sediment yield for a meso-scale catchment in the Southern Pyrenees. Catena 79: 288–296.
Pizzuto J, Moglen G, Palmer M and Nelson K, 2007. Two model scenarios illustrating the effects of land use and climate change on gravel riverbeds of suburban Maryland, USA. Developments in Earth Surface Processes 11: 359-381.
Rinaldi M, Wyzga B and Surian N, 2005. Sediment mining in alluvial channels: Physical effects and management perspectives. River Research and Applications 21(7): 805-828.
Snelder TH, Lamouroux N and Pella H, 2011. Empirical modelling of large scale patterns in a bed surface grain size. Geomorphology 127: 189–197.
Vignat D, 2003. Characterization of bed sediment and suspension of the river Po (Italy) during normal and high flow conditions. Water Resour Res (37): 2847-2864.
Wan X, Shang S, Yang W, Clary CV and Yang D, 2010. Simulation of land use–soil interactive effects on water and sediment yields at watershed scale. Ecological Engineering 36: 328–344.
Williams GP, 1983. Paleohydrological methods and some examples from Swedish fluvial environment, cobble and boulder deposits. Geogr Ann 65A: 227-243.
Williams GP and Costa J, 1988. Geometric Measurement after a Flood, Flood Geomorphology. John Wiley and Sons Publications. London.