IPATEC   26054
INSTITUTO ANDINO PATAGONICO DE TECNOLOGIAS BIOLOGICAS Y GEOAMBIENTALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Improving the forecasting of agricultural impacts from tephra fall
Autor/es:
HEATHER CRAIG; CHRISTINA MAGILL; OUTES, VALERIA; ALEC WILD; THOMAS WILSON; GUSTAVO VILLAROSA; CAROL STEWART
Lugar:
Puert Montt
Reunión:
Congreso; Cities on volcanoes COV 9: Understanding volcanoes and society: the key for risk mitigation; 2016
Institución organizadora:
SERNAGEOMIN
Resumen:
Agricultural land is often highly exposed to volcanichazards (such as tephra fall) due to its concentration in areas where weatheredvolcanic material has formed highly fertile soil. In order to better providebetter management strategies, an ability to forecast this risk is needed. Thedevelopment of predictive tools and models requires an understanding of therelationship between hazard intensity metrics, vulnerability characteristics,and the resultant impacts. This has been progressed by creating fragilityfunctions for different farm types that show the relationship between a givenhazard intensity metric (in this case tephra thickness) and the probability ofcertain impacts occurring. Impacts are represented through the use ofdamage/disruption states, which categorise impacts into a numeric scale. Thesecan then be modified through the use of a set of coefficients to include theinfluence of seasonal vulnerability and the fluoride levels within the tephradeposit.  Three notable events used toinform the functions were the 1991 Hudson, 2008 Chaitén, and 2011 Cordón Caulleeruptions. These were ideal case studies as they were large silicic eruptionsthat deposited varying thicknesses of tephra on thousands of farms in Patagoniadistributed across a variety of climates and production styles. In-field impactassessment studies in these areas were used along with a review of previousglobal impact assessments and expert input to form the basis of fragilityfunction development.  The fragilityfunctions thus developed were then used to create a probabilistic risk model forNew Zealand eruptive centres. This allows for the calculation of estimatedagricultural loss per sector with the annual probability of an event, leadingto the creation of probabilistic loss curves. These curves have importantapplications in the insurance industry and emergency management sectors.