Methodology has been developed to use the spectral width data of Terminal Doppler Weather Radar (TDWR), which is a C-band radar, to generate eddy dissipation rate (EDR) map in the vicinity of the Hong Kong International Airport. In this paper, the method is applied to the spectral width data of the long-range S-band radar in Hong Kong to generate EDR map for en-route aircraft flying around the Pearl River Delta region. The performance of such EDR maps is studied by considering two incidents of severe turbulence near Hong Kong at an altitude of 6 to 7 km. It turns out that the S-band radar based EDR maps could capture the occurrence of these severe turbulence events in association with isolated convective rain cells. The EDR values so calculated are compared with those obtained from the flight data, and the comparison results are generally satisfactory. This study shows the potential of using the spectral width data from the long-range radar in Hong Kong to generate EDR maps for the assurance of aviation safety.