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EGU General Assembly. EGU2010-10413. Emergency preparedness: community-based short-term eruption forecasting at Campi Flegrei J. Selva , W. Marzocchi , P. Papale , L. Civetta , E. del Pezzo. INGV-DPC Project UNREST. Vienna, 05/05/2010. INTRO. Emergency Preparedness
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EGU General Assembly EGU2010-10413 Emergency preparedness: community-based short-term eruption forecasting at CampiFlegrei J. Selva, W. Marzocchi, P. Papale, L. Civetta, E. del Pezzo INGV-DPC Project UNREST Vienna, 05/05/2010
INTRO Emergency Preparedness definition in advance of tools to assist decision makers • Short-term eruption forecasting keys: • to recognize anomalous signals and relate them to physical processes • ELICITATIONS • to assign probability values • STATISTICAL MODEL • 3. to quickly provide answers to unexpected phenomena • TRAINED COMMUNITY • ONLINE TOOLS
INTRO VOLCANOLOGICAL KNOWLEDGE STATISTICAL MODELS different interpretations different expertise big community expert on volcanic process ≠ expert in statistics INDERECT ELICITATIONS the community of experts set the parameters of the statistical model + STATISTICAL MODEL FORECASTING TOOL VOLC. COMMUNITY must be community based must be quickly reviewable = FORECASTING TOOL
BET_EF Statistical model: Bayesian Event Tree for Eruption Forecasting (BET_EF)
BET_EF MAGMATIC UNREST VENT LOCATION ERUPTION SIZE UNREST ERUPTION NODE 2 NODE 4 NODE 5 NODE 1 NODE 3 magma no magma loc #1 loc #2 … loc #700 lava dome small expl. medium expl. large expl. unrest no unrest eruption no eruption • NODE 1-2-3 • identification of anomalies indicating each “event” (node) • definition of the “state of anomaly” through thresholds • evaluation of the probability at node from the “state of anomaly” of all informative parameters
BET_EF PARAMETERS THRESHOLD 2 THRESHOLD 1 Anomaly: z Information: wz Probability: 1 - e-S{wz} MODEL BACKGROUND Gray Area ANOMALY measure
ELICITATIONS Volcanological interpretation: setting BET_EF through repeated elicitations
ELICITATIONS DELPHI METHOD • structured process for collecting and distilling knowledge from a group of experts, facilitating the formation of a group judgement: • structured information flows • feedback of participants • anonymity of participants GOAL: AGREED GROUP OPINION EXPERT GROUP • 30 researchers within 2 projects from 2005 • 5 elicitations sessions • scores of experts reflecting their consideration within the group • consensus is formed during general discussions • pre-eruptive node and tools • group of experts trained to ET and elicitation procedures
ELICITATIONS COMMUNITY-FORMING PROCESS Pre-elicitation meetings (seminars, meetings, internet forum): statistical model, tools for the elicitation, discussions on the monitoring network, studies/models (cross-feedback), interpretations (consensus-seeking) Elicitation sessions: physical meetings --> internet session score the other experts, selection of parameters and thresholds Post-elicitation meetings (moderated discussions sessions): consequence of choices and performance of the model, general discussions on single parameters, measures and definitions, etc.
ELICITATIONS ONLINE ELICITATION – http://bet.bo.ingv.it/elicitazione/elicitations.html • DURING ELICITATION • Predefined lists of experts and parameters • Online forms to • selected parameters • assign thresholds • vote the other experts • Online forum • ANALYSIS OF THE RESULTS • Automatic analysis • Stability check through differentiated statistical analyses • Automatic publication of results
RESULTS Results for CampiFlegrei (project INGV-DPC UNREST)
RESULTS LEGENDA: Boolean parameters are represented by “YES” “Gray areas” correspond to variable probability of being in the adjacent states, depending on the measured values
RESULTS Seismicity: Highest sensitivity Deformation: Macroscopic changes Gases: Macroscopic changes In Favour of Seismicity: Longest sesmic record and experience, exceptional sequence largely documented in 1982-84, more developed network, rapidity of information, effective higher sensitivity, … Against Deformation and Gases: Interpretations too model-dependent, many contrasting interpretations, large control of hydrothermal system, delayed gas-related signals, …
RESULTS • SUMMARY • Statistical model (BET_EF) and volcanological interpretation are kept separated: • separate validations are possible • experts asked for volcanological interpretationonly • an automatic and easily reviewable tool for eruption forecasting is set • The 5 yrs long elicitation process provided • a global picture of the confidence on the various volc. interpretations • clues to guide future implementations in the monitoring network and research investments • trained a community of experts to quickly answer to crises