Impact assessment after the typhoon Haiyan

Screenshot(s) of the interactive content as of 31 12 2013

Screenshot 1
Screenshot 1
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This interactive mapping tool shows the severe impact of the Typhoon Haiyan on population, housing units and some major crops in the Philippines. It provides a number of geo-referenced datasets collected from various sources and updated reports. The maps on impact assessment were prepared by the Geospatial Unitof the Land and Water Division of FAO, in response to the call for needs assessment and coordinating humanitarian assistance in agriculture and fisheries sectors.

The assessment

The assessment was done by first georefencing, harmonizing and creating a central database in the UTM WGS 84 reference system. Areas of crop growth stages were analyzed according to their stage at the time of the event. Major season and secondary season for rice were considered for analysis at the time of the event. The areas of standing rice at the moment of the event were mapped using the district level crop calendars for the major season. Also the planted rice areas for the second season were mapped.
The affected area was then calculated considering both these areas which were considered as area loss, calibrated by the severity intensity rate class. The extent (ha) and fraction (%) of the potential affected crop areas was calculated by intersecting the tropical cyclone severity areas with the administrative layers, arable land and permanent crops, annual harvested area, yield and production for year 2012 (which was used as a proxy to assess the planted area).

Severity zones

Severity zones were mapped using data from the EC-JRC updates based on the Public Storm Warning Signals (PSWC) in four main levels: S1-very high for PSWC #1, S2-high for PSWC #2, S3-medium for PSWC #3 and S4-medium-low for PSWC#4.
The severity area mask was calibrated using remote sensing data combined with the data reported on November 13, 2013 by the National Disaster Risk Reduction and Management Council of Philippines.
The severity intensity rate was classified proportionally with the affected population figures.

The crops

Major crops which were affected include rice paddy, coconut and sugar cane. The maps show the impacts of the tropical cyclone on these crops. The outputs were classified in 5 classes of affected areas: less the 10%, 10-25%, 25-50%, 50-75%, and >75%. The tabular information provides information on the estimated affected area for Rice Paddy (extent in ha and share in percentage) by Typhoon Haiyan severity Level and by District (updated on 15 November 2013). The affected planted areas for each severity zone were calculated as a fraction of the planted area versus by severity zone by administrative unit area. In addition, the analysis was done for major livestock, pig, poultry and cattle, affected population.