The estimation of wind gusts during a hurricane's passage at a particular site is important when considering the design of structures in hurricane prone regions. Difficulty lies not only in obtaining unfragmented wind data from surviving anemometers but also in accounting for the terrain exposure of the anemometer. Recently, a study by Krayer and Marshall (1993) showed that gust factors (ratio of the peak wind gust to the mean wind speed measured over an interval of time) calculated from hurricanes records might be greater than for other, conventional wind records. In addition, the estimation of the surface roughness length is important in the adjustment of wind records to a standard exposure for comparisons. A formula developed by Wieringa (1973) can be employed to calculate the surface roughness length from the gust factors of a wind record if the specifications of the recording instrument are known.
This study will take wind records from two different hurricanes, Bob in 1991 and Iniki in 1992. In the case of Bob, a digital record was obtained from an anemometer operated by the Army Corps of Engineers at Duck Island, located on a barrier island in North Carolina - while for Iniki, a strip chart was obtained from a NWS recording station at Lihue Airport in Lihue, Kauai. In each case, 10-minute gust factor analysis was employed and surface roughness lengths were calculated as the hurricanes passed each site.