A survey on protection works databases used at the Alpine Space level: analysis of contents and state of the art related to protection works effectiveness assessment

[Departement_IRSTEA]Eaux [TR1_IRSTEA]RIVAGE

anglais. Natural phenomena in mountainous areas put people and assets at risk. Risk is classically assessed as a combination of hazard and vulnerability. Hazard relates to the intensity and frequency of phenomena, whereas vulnerability concerns damage and values assessment. Risk reduction measures and strategies are based on non-structural measures such as land-use control through risk zoning maps, preventive information and structural measures such as civil engineering protection works (check-dams, snow nets, etc.). To ensure prevention and limit risks, protection works have an essential role to reduce both causes and effects of phenomena. Decision-aid tools are needed for long term monitoring and management of protection works. Assessing their effectiveness considering both their structural state and functional abilities is challenging. This survey gives a picture in 2014 of the existing processes for protection works monitoring (databases) in France (ONF RTM1), Austria (TAC2) and Italy (Autonomous Region of Valle d’Aosta and Autonomous Province of Bolzano). We analyze options taken in existing databases to monitor effectiveness indicators. We compare the use of collected data during the monitoring of protection works. Finally, we identify best practices used in the monitoring of protection systems that should be included in future upgrading of databases. The survey was divided in 3 steps: i) development of a questionaire related to protection work databases and the assessment of effectiveness and efficiency concepts, ii) analysis of existing databases, iii) formulation of recommendations. The comparison of databases gives the following global picture. Having an overview of existing protection systems and assessing their condition are common initial objectives of databases. Decision support objective to plan interventions is not clearly expressed. Indicator definitions to describe works are different. Protection works assessment is based on expert field analysis. Structural condition is always assessed unlike functional ability. Comparing protection works with exposed elements they protect and natural hazards they reduce is not registered in databases. For a better design, interoperability and management of databases on protection works and their effectiveness, it is recommended to i) enlarge the survey to all Europe, ii) establish a common expert English glossary, iii) improve database management capacities (definition of objectives, organization, etc.), iv) upgrade existing databases from a registration tool to a decision-aid tool for a relevant protection works management.