Report No. : GEO Report No. 22
Report Title : Report on the Rainstorm of 8 May 1992 (1993), 109 p. plus 2 drgs. (Reprinted, 1995)
Author : N.C. Evans
This report presents a general review of the rainfall of the severe rainstorm on 8 May 1992 in Hong Kong and the landslides which occurred as a result. In summary, the rainfall on 8 May 1992 was very heavy and intense. The Royal Observatory recorded a maximum hourly rainfall of 109.9 mm between 0600 and 0700, the highest ever recorded at this location. The estimated return period for rainfall of this magnitude is about 70years. The rainfall was concentrated on the Kowloon Peninsula and the northern and western parts of Hong Kong Island. There is a good correlation between the distribution of rainfall and the distribution of landslides. In total 350 landslides reported to the GEO could be attributed to the 8 May rainstorm. Seventeen of these landslides were majormajor (> 50 m3), whereas 194 were very small (< 5 m3). The Landslip Warning was issued at 0620 on the morning of 8 May. Of the 72 landslides for which the time of occurrence is known to within one hour, three occurred before the Landslip Warning was issued and 69 occurred afterwards. The landslides caused three deaths and five injuries. Ninety-two squatter huts were permanently evacuated and seventeen were temporarily evacuated. Twenty-two buildings were partly or completely evacuated. Sixty-four sections of road and 29 sections of miscellaneous access were partly or completely blocked or closed.