Chapter 4 - Global change, related impact on natural hazard processes, and potential consequences in social-ecological mountain systems

Abstract

Mountain social-ecological systems are currently undergoing significant alterations due to changing climate and other environmental conditions as well as social-economic parameters such as urbanization or demographic aging, directly or indirectly influencing the frequency and magnitude of multiple natural hazard processes. This applies to different altitudinal belts and to the processes of both, gradual alterations and sudden events. Changing hazardscapes in mountain areas are influenced by three main drivers and their changing characteristics: the relief, the hydroclimate, and human activities (land use). For example, melting glaciers may cause a change in meltwater discharge, increasing the frequency and/or magnitude of floods and high sediment transport along the rivers. The partly already observed increase in heavy precipitation in many mountain regions may influence the triggering of landslides and debris flows, particularly in areas with environmental pressures such as vegetation cover transition or overgrazing. At the same time, demographic change, economic development, and geopolitical developments alter both the exposure and vulnerabilities of mountain populations to natural hazard processes which may, in turn, lead to changes in potential damage patterns. Even though interconnectedness between different risk-influencing drivers (hazard, exposure, vulnerability) and patterns are undoubtable, evidence for associated system response and quantification of the linkages between different risk drivers is still in its infancy for many mountain regions.