River morphodynamics and flood risk assessment: a case study of Ghaghra River at Ayodhya reach

Student name: Mr Aadil Hamid Ganie
Guide: Dr Amit Singh
Year of completion: 2025
Host Organisation: 2M SHAN Engineering Solutions Pvt Ltd.
Supervisor (Host Organisation): Dr Subash Prasad Rai

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Abstract:

This study assesses river morphodynamics and flood risk along the Ayodhya Reach of the Ghaghra River (India) using geospatial and hydraulic modeling. Multi-temporal satellite imagery (2000–2024) was analyzed with the Digital Shoreline Analysis System (DSAS) to quantify bankline migration, revealing significant lateral movement dominated by east-bank erosion (mean rates: −35 to −38 m/year). Custom metrics classified channel behavior (e.g., narrowing, widening, migration direction) at 100-m intervals. Forecasts projected increased sinuosity by 2037. These morphodynamic outputs informed 2D HEC-RAS flood simulations for 10-, 50-, and 100-year events, dynamically updating channel geometry to reflect erosion/accretion. Results show a 17% expansion in flood inundation area by 2035 for 50-year events, with heightened depths. The integrated approach demonstrates that channel migration directly amplifies flood hazard extent and severity. Findings support urgent floodplain management and infrastructure planning in this dynamic reach.”

KEY WORDS: DSAS, BankLine, Migration, Change Type, 2D HEC RAS, Forecast.