Lars Grande

Methodology for geohazard assessment for hydropower projects

The paper presents a comprehensive methodology for a multihazard assessment, including an associated multihazard monitoring programme. An existing method in system theory is extended for multiple systems and used to demonstrate the importance of considering geohazard interrelations in the safety monitoring of reservoirs and dams. The method is applied to systems of geohazards and monitoring parameters. In both systems, there is a reservoir retained by one or more dams. Geohazards in hydropower project perspectives as well as monitoring opportunities are classified. The results are presented in a colour-coded matrix visually mapping ranked interrelations for the two systems. The methodology proposed provides a clear view on the prospective that individual geohazards may trigger other geohazards as well as on the geohazard-triggering potential of the reservoir itself. The warning potential of the possible monitoring parameters is also mapped and interrelated to the individual geohazards. The results demonstrate the importance of a comprehensive multidisciplinary monitoring programme for reliable operation and risk management of hydropower projects.

Interrelations in multi-source geohazard monitoring for safety management of infrastructure systems

In this paper a methodology is put forward for enhancing safety by linking multi-source monitoring to multi-hazards threatening infrastructure systems. An application is demonstrated with a conceptual model comprising two systems. One system includes the infrastructure, exemplified by a reservoir and its dams, along with settings for geohazards. The other system contains the associated monitoring possibilities. Interrelations are quantitatively explored by applying an existing method of systems theory, extended to include multiple systems. This is used to investigate geohazard-triggering potential, interaction intensity and dominance. It is further used to explore the reaction of monitoring components to geohazard action as well as safety values of the monitoring system and its components. The interrelations established have a general relevance for the consideration of geohazards threatening reservoirs and dams, and the associated monitoring. This is explained with a case study. Moreover, the interrelations can be used for defining hazard chains in multi-hazard assessment, planning of monitoring programmes and detecting precursory pathways within a monitoring system. The methodology constitutes the basis for comprehensive safety and risk management embracing, multi-hazard assessment as well as structural health monitoring.