Evolution of Geomorphologic Hazards in Hindu Kush Himalaya

Abstract

Geomorphologic hazards in the Hindu Kush regions have been evolved due to the combined effect of tectonic settings, topographical variation, weak geological conditions, intense seasonal precipitation and the changes in climatic conditions. The underlying risk has been further intensified by human interference that arises either due to poverty, poor policy or weakness in implementing the policies. Tectonic setting of the Hindu Kush region has been originated due to the collision between southern Indian plate and northern Eurasian plate. The Himalayan Orogeny is thus developed and consequently earthquake hazard is evolved which is unavoidable. Weak geological conditions, diversified rock types, high degree of weathering in rocks and rock deformations all have contributed to most of the geomorphologic hazards. High gradient of rivers and extreme monsoon precipitation indicate that the upstream and downstream of major river basins are strongly interrelated and the risk of hazards like landslides, floods and debris flows in the upstream pose serious threat to the downstream flood as well. The impact of climate change, high rate of temperature rise and extreme rainfall events has exacerbated the landslide, flood, debris flow and Glacial Lake Outburst Flood (GLOF) hazards. At least one GLOF event was recorded in Himalayan region between every 3–10 years. All these hazards shape the landscape of the region and create severe problems on water resources as well as other development projects. These hazards have worst impact to people and livelihood by destroying their environment for living and production, thereby seriously affecting social and economic development. This chapter analyzes the major triggers of the geomorphologic hazards in HK regions with the scientific facts and figures.