Himalayan Flood Hazards

This book presents the autogenic and allogenic consequences of Himalayan floods on a spatio-temporal scale. Himalayan flooding has become an environmental issue in recent years. The monsoon, non-monsoon and hybrid floods are reactivated year after year, causing heart-rending human tragedy and emerging as a disaster over the entire Himalayan terrain, from higher altitudes to the foothills. Along with climatic consequences, engineering constructions, land-use practices, unscientific boulder excavation, and a lack of river buffer zone maintenance impressively govern the devastating layout of floods in different modes. The most geo-tectonically and ecologically sensitive Himalayan regions face natural calamities such as intense earthquakes, massive landslides, glacier lake outburst floods (GLOF), cloudbursts and flash floods occurring in a devastating form. Recent Himalayan floods have been characterized by a "deadly cocktail" of rapid climate change, geological fragility, and aggressive infrastructure development, causing multiple types of disasters, particularly during the monsoon season, and river morphological dynamics, such as channel shift, accelerated bank erosion, channel widening, and substantial sediment deposition in Himalayan rivers, may intensify the loss of human resources, ecology and the area’s economy. However, the increase in flood frequency and coverage area has led to the rehabilitation of human beings. This book encompasses the geo-environmental and climatic consequences in flood genesis from the higher levels to the foothill areas of the Himalayan arc, and includes case studies as evidence of flood effects on channel morphology, ecology, human behaviour, rehabilitation and the economy.