Forest fire damage assessment and landslide risk, Madeira Island, Portugal (2016-11-11)

Activation date: 2016-11-11
Event type: Other

Activation reason:
This activation focuses on damage assessment and landslide risk assessment relating to major forest fires in the municipalities of Funchal and Calheta, Madeira in August 2016. Key assets (infrastructure, environment, human life, economic sustainability, etc.) are also identified and related with the severity of impact. The service involves:Post‐disaster assessment referring to loss of forest resources: Damage extent and gradingPre‐disaster mapping through an evaluation and assessment of landslide riskTo optimize the efficiency of the preventative measures to be implemented, risk maps (landslides) and damages maps (burnt areas, grading) at large scale (1:5,000) were generated.The core users are the Autoridade Nacional Prote[HTML_REMOVED][HTML_REMOVED]o Civil (ANPC) and the Institute of Nature Conservation and Forests (ICNF) of Portugal.The method used for burnt area delineation and burnt severity grading is based on thresholding of spectral indices, namely the NDVI and its differentiation in time (dNDVI) derived from pre-fire Pl[HTML_REMOVED]ades image and post fire (two dates) SPOT 6 and 7 acquisitions. Another index which was also calculated and used in combination with the NDVI/dNDVI is the Enhanced Vegetation Index (EVI) and its time differentiation dEVI.For the assessment of landslide risk, the Norwegian Geotechnical Institute (NGI) methodology was employed, which is a function of slope gradient, lithology, vegetation cover and soil moisture and based on a triggering factor of 100 year extreme monthly precipitation. [HTML_REMOVED]Landslide risk was computed by overlaying the vulnerability assessment with the hazard map and it is categorized at different levels, based on the likelihood of landslide occurrence where assets are exposed, following the risk matrix of the European Commission [HTML_REMOVED]Overview of natural and man‐made disaster risks in the EU[HTML_REMOVED] (COM 2014).Tables on each map indicate the number of residents, built up surface area, the number of Points of Interest (POIs) and road segments (km) of the exposed elements at various risk levels (Very Low, Low, Medium, High, Very High).[HTML_REMOVED]