Integrating and geolocating post earthquake building damage surveys: The 7.8 Mw Jama-Pedernales earthquake, Ecuador
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Currently, it is fairly widespread to use smartphones or tablets on field surveys to collect and geolocate damage data. However, geolocation is not a straight forward process and may give inaccurate results such as, for example when the size of the object to be surveyed is relatively small or the coverage of the satellite constellation (e.g. GPS) is inadequate due to obstacles and shadows present in urban areas. Moreover, the pressure that surveyors and technicians suffer during and after the impact of a natural hazard may make the whole geolocation process even more difficult. In this paper, we describe a methodology to overcome the issues of inaccurate records in five damage data surveys collected after the 7.8 magnitude earthquake that struck the coast of Ecuador in April 2016, together with the three administrative sources used to interpret the damage. We started off by homogenizing the various states of damage as charted in field and aerial surveys, including satellite imagery. We then resolved geolocation inaccuracies by using a set of algorithms that take into account the spatial context and the size of the building. These algorithms also flag the quality of the sources to ultimately compute a figure of the spatial distribution of the damage suffered by residential buildings, together with harm done to productive and social infrastructure. Without these preliminary proceedings, the geolocation inaccuracies of the damage data surveys would not have allowed for adequate and detailed risk assessment.
KeywordsGeolocation Seismic risk analysis Jama-Pedernales earthquake Portoviejo Ecuador
This work has been significantly supported by the Secretaría de Educación Superior de Ciencia, Tecnología e Innovación (SENESCYT) of the Government of Ecuador under the PROMETEO Programme (PROMETEOCEB- 004-2015 and PROMETEO-CEB-009-2016). Special thanks are extended to the members of the “Unidad Técnica de Riesgos” of the Municipality of Portoviejo, MSc. Jhonny García, Ing. Manuel Vera, MSc. Julio Celorio, and Ing. Gastón Loor, for their help and collaboration during the field work and data acquisition.
Compliance with ethical standards
Conflict of interest
On behalf of all the authors, the corresponding author states that there is no conflict of interest.
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