Summary and Outlook

Torrential activity on alluvial fans and debris cones represents a major hazard in many regions where human settlements and infrastructure expand into potentially endangered areas. For the assessment of hazard and risk, detailed knowledge about past torrential activity and reliable predictions of possible future evolutions are of crucial importance. Data can be obtained from various data sources as has been shown in the previous chapters of this book. It is obvious that all methods have their advantages and their limitations and that their application always depends on site specific conditions and on the type of information sought. To obtain the best possible data with highest accuracy for a better estimate of hazards and risk on a fan or cone, a multi-method approach often represents the best solution. It is also important to notice that current frequencies and magnitudes will not necessarily remain the same in the future. We should be aware that there is a long chain of dependencies and uncertainties from a changing climate to the impact on natural hazards.