17:15 〜 19:15
[AHW29-P04] Flood Frequency Analysis and Risk Assessment on Ganga Basin Catchment using Geospatial Techniques
キーワード：Flood Modelling, Hydrological Modelling, Hydraulic Modelling, Flood Inundated Area, Return Period, Flood Frequency Analysis
Rivers serves as fundamental life support systems that have sustained civilizations for centuries. However, rapid urbanisation and population growth have significantly altered river patterns and its discharge carrying capacity by impacting their natural functions. Present study investigates the effects of climate variability and anthropogenic influences on the upper Ganga basin which is one of the most critical and influential river basins. Upper Ganga Basin is situated in the northern part of India covering around 20,000 Km2 in area. The primary focus of this study was to assess and mitigate flood risks in the study area. To achieve that a basin model was developed, followed by a return period analysis for 2, 10, 50 and 100 years to evaluate flood probabilities and potential impacts. Daily discharge data of 17 years (2006 to 2022) was collected from the Central Water Commission, and other data required for the study included high resolution satellite imagery, Digital Elevation Model (DEM), Daily Precipitation data and soil map. HEC-HMS and HEC-RAS were used for hydrological and hydraulic modelling. Flood inundation maps were developed using ArcMap and HEC Series. Hydrological model of the study area was calibrated and validated for the years 2006-2018 and 2019-2022 respectively in HEC-HMS. The model showed root mean square value of 1.1. Results of the present study demonstrates that a minimum of 241km2 area is inundated for a 2-year return period and a maximum of 270km2 area is inundated for a 100-year return period. Whereas the peak discharge ranges from 1766 m3/s to 7349 m3/s for a return period of 2 to 100 years. This study provides a methodological framework for similar research on flood risk assessment in other flood prone areas and emphasizes the need for low impact development strategies to mitigate flooding. The findings highlight the importance of integrating advanced flood modelling techniques with historical data to enhance disaster preparedness and resilience in vulnerable regions.