The proposal for “unified terrain categories exposures and velocity profiles” by Choi in 2009 has been evaluated extensively. On the basis of 6 articles in open literature (3 papers during Typhoon Muifa in 2011, one during Hurricane Ike in 2008, one during Typhoon Sally in 1996, and one during an atmospheric dispersion experiment in New York City, USA) and nearly simultaneous upper-air measurements when available, it is found that the proposed criteria (except the displacement height) by Choi are evaluated to be useful operationally for engineering applications. An alternative approach using the mean building height (rather than the displacement height)as the input to estimate the power-law exponent and the gradient height is proposed for practical use.
The proposal for “unified terrain categories exposures and velocity profiles†by Choi in 2009 has been evaluated extensively. On the basis of 6 articles in open literature (3 papers during Typhoon Muifa in 2011, one during Hurricane Ike in 2008, one during Typhoon Sally in 1996, and one during an atmospheric dispersion experiment in New York City, USA) and nearly simultaneous upper-air measurements when available, it is found that the proposed criteria (except the displacement height) by Choi are evaluated to be useful operationally for engineering applications. An alternative approach using the mean building height (rather than the displacement height)as the input to estimate the power-law exponent and the gradient height is prosed for practical use.