[01] Kuldeep Pareta, Water Resource Department, DHI (India) Water & Environment Pvt Ltd., New Delhi, India. [02] Upasana Pareta, Omaksh Consulting Pvt. Ltd., Greater Noida (West), Uttar Pradesh, India.

The Rapti river and its tributaries are meandering river, consisting of a variable number of meander bends, which change their locations and sizes each year. The most significant bankline modifications take place during the receding stages when excess sediment is deposited as point bars, side bars along the main channel, causing changes in local flow directions and migration of the thalweg. During floods river hydraulics change inducing variations in sediment transport characteristics and erosive forces, and the channel starts shifting at several vulnerable reaches. Understanding the flow of river and flow of hydraulic structures helps in their proper planning, design, and maintenance. Hydraulic analysis is made up of downstream and downstream hydraulic structures such as barrages and spurs such as sediment deposition upstream and skewed hydraulic jumps downstream as a result of insufficient energy dissipation. Therefore, the morphological studies have played an important role in sustainable river management, and restoration structures as well as flood risk mitigation. To solve this problem, we have done various study like effect of barrage, embankment, spurs on river morphology; and development of embayment between spurs. The study area needs corrective measure, appropriate planning, and governmental support to stabilize the riverbank lines and protect riverbank from erosion.

River Morphology, Rapti River, Bank Protection Structures, Remote Sensing, and GIS

[01] Leopold LB, Wolman MG. 1960. River MEANDERS. Bulletin of the Geological Society of America. Vol. 71 (6), pp. 769-794. [02] Edwards BF, and Smith DH. 2002. River meandering dynamics. Physical Review E. Vol. 65, pp. 1-12. [03] Hooke J. 2003. Coarse sediment connectivity in river channel systems: A conceptual framework and methodology. Geomorphology. Vol. 56, pp. 79-94. [04] Hooke JM, and Yorke L. 2011. Rates, distributions and mechanisms of change in meander morphology over decadal timescales, River Dane, UK. Earth Surface Processes and Landforms. Vol. 35, pp. 1601-1614. [05] Legleiter CJ, Harrison LR, and Dunne T. 2011. Effect of point bar development on the local force balance governing flow in a simple, meandering gravel bed river. Journal of Geophysical Research. Vol. 116, pp. 18-38. [06] Kasvi E, Alho P, and Vaaja M. 2013. Spatial and temporal distribution of fluvio-morphological processes on a meander point bar during a flood event. Hydrology Research. Vol. 44 (6), pp. 1022-1039. [07] Klingeman PC, Kehe SM, and Owusu YA. 1984. Streambank erosion protection and channel scour manipulation using rockfill dikes and gabions. Water Resources Research Institute Technical Report WRRI-98. Oregon State University, Corvallis, OR. [08] Shields JFD, Knight SS, Morin N, and Blank J. 2003. Response of fishes and aquatic habitats to sand-bed stream restoration using large woody debris. Hydrobiologia. Vol. 494 (1-3), pp. 251-257. [09] Wang H, Yang Z, Saito Y, Liu JP, Sun X, and Wang Y. 2007. Stepwise decreases of the Huanghe (Yellow River) sediment load (1950-2005), impacts of climate change and human activities. Global and Planetary Change. Vol. 57, pp. 331-354. [10] Bormann NE, and Julien PY. 1991. Scour downstream of grade-control structures. Journal of Hydraulic Engineering. Vol. 117, pp. 579-594. [11] Lu JY. Hong JH. Chang KP, and Lu TF. 2013. Evolution of scouring process downstream of grade-control structures under steady and unsteady flows. Hydrological Processes - Wiley Online Library. Vol. 27, pp. 2699-2709. [12] Guan D, Melville BW, and Friedrich H. 2015. Live bed scour at submerged weirs. Journal of Hydraulic Engineering. Vol. 141, pp. 0401-407. [13] Sattar AMA, Plesiński K, Radecki-Pawlik A, and Gharabaghi B. 2017. Scour depth model for grade-control structures. Journal of Hydro-informatics. Vol. 20, pp. 117-133. [14] Bhusal JK. 2004. Consequences of river training structures - a case of Laxmanpur barrage and afflux bunds near Indo-Nepal border. Journal of Hydrology and Meteorology, Soham-Nepal. Vol. 1 (1), pp. 1-5. [15] Adhikari BR. 2013. Flooding and inundation in Nepal terai: issues and concerns. Hydro Nepal. Vol. 12. pp. 59-65. [16] Gautam DK and Phaiju AG. 2013. Community based approach to flood early warning in west Rapti river basin of Nepal. Journal of Integrated Disaster Risk Management. Vol. 3 (1), pp. 155-169. [17] Shrestha HM. 2016. Naumore storage project should be the last resort of development on the main course of Rapti (West), Nepal. Hydro Nepal. Vol. 18. pp. 1-5. [18] Pareta K. 2020. Effect of Laxmanpur barrage on the river system - a case study through multi-temporal satellite remote sensing data. Indian Journal of Engineering. Vol. 17 (48), pp. 443-449. [19] Osti R. 2008. A feasibility study on integrated community-based flood disaster management Banke district Nepal, phase-1 baseline study. International Centre for Water Hazard and Risk Management (ICHARM), Public Works Research Institute (PWRI). No. 4122 (11), pp. 1-111. [20] NDRI. 2012. Assessment of flood inundation in lower west Rapti basin under the effect of climate change. Nepal Development Research Institute (NDRI), Kathmandu, Nepal. pp. 1-113. [21] Sanstha JV. 2014. Climate vulnerability and gap assessment report on flood and drought (lower Rapti river Basin case study). Global Water Partnership (GWP), Nepal and Jalsrot Vikas Sanstha (JVS). pp. 1-45. [22] Devkota RP 2014. Flood adaptation strategies under climate change in Nepal - A socio-hydrological analysis. Ph.D. Thesis, University of Southern Queensland. [23] UNDP. 2009. ISDR global assessment report on poverty and disaster risk. United Nations Development Programme (UNDP), Kathmandu, Nepal.