Models for river avulsions have identified the ratio between down-valley and cross-valley slopes of channels as the triggering factors for the sudden channel shift but have remained untested in the field. The August 2008 avulsion of the Kosi River at Kusaha, 12 km upstream of the Kosi barrage in Nepal, provided an opportunity to study a large-scale avulsion (~120 km) for its causal factors and driving mechanisms.
The Kosi river in north Bihar plains, eastern India presents a challenge in terms of long and recurring flood hazard. Despite a long history of flood control management in the basin for more than 5 decades, the river continues to bring a lot of misery through extensive flooding. This paper revisits the flooding problem in the Kosi river basin and presents an in-depth analysis of flood hydrology.
The Kosi river in north Bihar plains, eastern India presents a challenge in terms of long and recurring flood hazard. Despite a long history of flood control management in the basin for more than 5 decades, the river continues to bring a lot of misery through extensive flooding. This paper revisits the flooding problem in the Kosi river basin and presents an in-depth analysis of flood hydrology. The study integrates the hydrological analysis with a GIS-based flood risk mapping in parts of the basin. Typical hydrological characteristics of
Flood hazard in a basin depends upon the hydrological response of the upstream basin area. The upstream basin area may produce different amounts of run-off for a given rainfall based on its hydrologic response. The present communication shows the importance of drainage network characteristics in understanding the hydrologic response of a basin. The study is carried out through Geomorphic Instantaneous Unit Hydrograph analysis, wherein Horton's morphometric ratios were used to define the drainage network. A floodprone river basin in north Bihar plains has been selected as a study area.
Flood hazard is one of the most severe problems in the Himalayan river basins. Although floods are essentially hydrological phenomenon, the uneven distribution of floods in the river basin highlights the control of geomorphological and geological factors. A proper understanding of these factors is critical for a successful flood management programme. Remote sensing data is of immense value in evaluating the geomorphological and geological controls in flooding. The present paper highlights the control of geomorphology and neotectonics on flood hazard in north Bihar Plains, eastern India.
The Indo-Gangetic plains are drained by several fan and interfan rivers fringing the margin of the outer Himalaya. These fan and interfan river systems are distinctly different from each other in terms of hydrology and sediment transport and generate typical
