Damage Assessment of the 2020 Monroe, Louisiana, Tornado Using Different Remote-Sensing Methods and Enhanced Fujita Scales

In 2014, the American Society of Civil Engineers (ASCE), the Structural Engineering Institute (SEI) and the American Meteorological Society (AMS) undertook the effort of developing a standard for tornado wind speed estimation, which will officially standardize the EF-Scale, and introduce additional wind speed estimation methodologies. The “Easter Sunday” tornado that occurred on April 12, 2020, in Monroe, Louisiana, provided an opportunity to use a draft version of the EF-Scale method that is being prepared for this ASCE/SEI/AMS standard to assess damage because multiple reconnaissance teams were deployed to document the damage using different remote-sensing data sets. The data collected from street-level imagery and uncrewed aerial systems were used in this study to compare the 2006 EF-Scale and draft standard, as well compare the damage evaluations of buildings and trees across different evaluators. Statistical analysis was conducted for the differences between assessments of buildings inspected, the majority of which were one- and two-family residences. Correlation values in the damage evaluation were found to be low between evaluators when buildings had nonstructural damage (broken windows or loss of roof covering or siding), and the analysis highlighted the limitations of each of the remote-sensing data sets. A major recommendation of this study is to omit resistance indicators from the description of the degrees of damage in the new ASCE/SEI/AMS EF-Scale method, to further limit subjectivity.