The Impacts of Sediment Transport on the Width of Ajichai River Flood Zoning

Document Type : Research Article


1 MA Student, University of Tabriz, Tabriz, Iran

2 Professor, Faculty of Civil Engineering, University of Tabriz, Tabriz, Iran

3 Assistant Professor, Department of civil Engineering, Marand Faculty of Technical and Engineering, University of Tabriz, Tabriz, Iran


Flood zoning maps are among the basic and important sources of information for studying development projects in the world. In the conventional method of determining flood zoning maps, calculations are performed on the basis of a steady flow, assuming a fixed bed (without considering sediment transport). This study aimed to investigate the impact of river erosion and sediment transport on river flood zoning. So, the flood zoning calculations of Ajichai River were done using HEC-RAS model and the conventional method of steady flow with a fixed bed. In the next step, flood zoning calculations were performed using quasi-steady flow with moving bed and compared with the results of the previous step to determine the impacts of sediment transport on flood zoning. Comparison between the results obtained from steady flow (fixed bed) and quasi-steady flow with moving bed showed that in sedimentation sections, the width of the water surface increases in the flow mode with moving bed. The maximum rate of this increase in width is 19%. In other words, in the mentioned river, the width of flood zoning is less in the conventional method. This issue confirms the necessity of studying the river conditions in terms of erosion and sedimentation so that the amount of flood zone could be determined more accurately while the river is sedimentary. The increase of flood zone in sedimentation sections is due to the accumulation of sediments and consequently the increase of flow level and width of flood zonation. Therefore, it is suggested that in sedimentary rivers, a quasi-steady flow model (mobile bed) be used to prepare flood zoning maps for providing more safety.

Graphical Abstract

The Impacts of Sediment Transport on the Width of Ajichai River Flood Zoning


برخوردار، م؛ چاوشیان، س. ع. 1379. پهنه‌بندی سیلاب. مجموعه مقالات کارگاه فنی روش‌های غیر سازه‌ای مدیریت سیلاب، کمیته‌ ملی ‌آبیاری‌ و زهکشی‌ ایران، کمیته ملی کاهش اثرات بلایای طبیعی،  19 صفحه.
پورنبی درزی، س؛ وفاخواه، م؛ رجبی، م.ر. (1400) پهنه‌بندی خطر سیل با استفاده از مدل هیدرولیکی HEC- RAS و Arc GIS. مطالعه موردی: حوزه آبخیز چشمه کیله شهرستان تنکابن. نشریه مخاطرات طبیعی، 10(28)، 15-28.
تیموری یگانه، م؛ آرمان، ع. 1399. برآورد دبی انتقال رسوب رودخانه شاهرود با استفاده از مدل ریاضی HEC-RAS. نشریه علمی پژوهشی مهندسی آبیاری و آب ایران، 10(4): 18-32.
حسن‌زاده، ر؛ هنرمند، م؛ حسینجانی‌زاده، م؛ محمدی، ص. (1400). پهنه‌بندی سیلاب در نواحی شهری با استفاده از مدل هیدرولوژیکی و اطلاعات میدانی (مطالعۀ موردی: سیل بردسیر، استان کرمان). اکوهیدرولوژی، 8(2)، 331-344.
حسن‌زاده، ی. 1391. هیدرولیک رسوب مخازن. کمیته ملی سدهای بزرگ ایران.
غفاری، گ؛ امینی، ع. 1389. مدیریت دشت‌های سیلابی با استفاده از سیستم اطلاعات جغرافیایی (GIS) مطالعه موردی رودخانه قزل‌اوزن. فضای جغرافیایی, 10(32): 117-134.
قمی اویلی، ف؛ صادقیان، م.ص؛ جاوید، ا. م؛ میرباقری، س. ا. ۱۳۸۹. شبیه‌سازی پهنه‌بندی سیل با استفاده از مدلHEC-RAS  مطالعه موردی: رودخانه کارون حد فاصل بند قیر تا اهواز، نشریه علوم و فنون منابع طبیعی. ۵(۱): ۱۰۵.
Brunner, G. W., Gibson, S., 2005. Sediment Transport Modeling in HEC-RAS. World Water and Environmental Resources Congress.
Chow, V.T., 1959. Open Channel Hydraulics. McGraw-Hill Book Co. New York, 680 p.
Cook, A., and Mervade, V., 2009. Effect of topographic data, geometric configuration and modeling approach on flood inundation mapping. Journal of hydrology. Vol (377): pp 131- 142.
Dumitrescu, V., Barbieru, A., Carsmariu, A., 2012. Research on the simulation of the alluvial transport on the numerical model and the estimation of the morphological modifications with application on the DANUBE riverbed for a proposed sector, in the period of 2005-2010. Proc. Int. Conf., water resources and Wetlands, Tulcea-Romania.14-16 pp. http:// water2012/ Proceedings/014.pdf
Ghimire, G. R., DeVantier, B. A., Sharma S., 2020.  Site-Specific Sediment Deposition Model for Dredging Planning: Case Study of Olmsted Locks and Dam. Journal of Waterway, Port, Coastal, and Ocean Engineering, Vol. 146, Issue 5.
Joshi, N., Gaurav Raj Lamichhane, G. R., Rahaman, M., Kalra, A., and Ahmad, S., 2019. Application of HEC-RAS to Study the Sediment Transport Characteristics of Maumee River in Ohio. World Environmental and Water Resources Congress. Hydraulics, Waterways, and Water Distribution Systems Analysis.
Mohammad Razi, M. A., Marimin, N. A., Ahmad, M. A., Adnan, M. S., & Rahmat, S. N., 2018. HEC-RAS Hydraulic Model for Floodplain Area in Sembrong River. International Journal of Integrated Engineering. 10(2). Retrieved from ijie/ article/ view/ 2645.
Regmi, R.K., 2021. Sedimentation Modeling of Karnali Chisapani Multipurpose Project Reservoir, Nepal. J. Inst. Eng. India Ser. A 102, 815–827.
Salman, A., Hassan, S.S., Khan, al., 2021. HEC-RAS and GIS-based flood plain mapping: A case study of Narai Drain Peshawar. Acta Geophys. 69: 1383–1393. https://  10.1007/s11600-021-00615-4.