Ghaghara River: A Case Study of Flood in Uttar Pradesh by GIS-Based Technique

Flooding is generally the overflow of water onto the lands that is normally dry. It is a major issue in worldwide and has affected many lives and land for several decades. It may not stop but can be preventive. Ghaghara River, the major tributary of Ganga River in Gangetic plain, has witnessed the floods of every year in monsoon season. Ghaghara River originated from Mapchachungo glacier in Tibet Mountain at a height of 4800 km near Mansarovar Lake. It travel to 507 km length in Nepal afterward reaches to India and cover 1080 km length up to it confluence to Ganga River at Doriganj, Chhapra town in Bihar. The present study has been initiated to flood risk zonation using multiple criteria analysis (MCA) for analyzing the major issue in Ghaghara basin. The thematic layers, i.e., interpolated rainfall; slope, micro watersheds, drainage density, land use/land cover, soil surface texture and soil moisture were used to delineate the flood hazard risk zonation map. Thematic map has been prepared by georeferenced imageries of Survey of India (SOI) toposheet and remote sensing satellite data (RS) of SRTM (Shuttle Radar Topography Mission) data and LISS –III (Linear Imaging Self Scanning). The study identified promising results for the establishment and categorization of flood risk zones into very low hazard risk zone (4%), low hazard risk zone (8.5%), moderate hazard risk zone (23.6%), high hazard risk zone (42%), and very high risk zones (21.9%). It is estimated on the basis of the study that ~27,490 localities were influenced by floods along the major channels, i.e., Ghaghara, Sarda, and Rapti. The results of this study could allow better relief operations and reduce the risk of flooding.