LCQ12: Rainstorm warning system
Following is a written reply by the Secretary for Commerce and Economic Development, Mr Gregory So, to a question by the Hon Cheung Hok-ming in the Legislative Council today (June 6):
Since the onset of the rainy season in April this year, the Hong Kong Observatory (HKO) has issued the amber rainstorm signal (amber signal) many times, indicating that heavy rain exceeding 30 millimetres (mm) in an hour has fallen or is expected to fall generally over Hong Kong; and when the amber signal was in force, severe flooding occurred in many places in Hong Kong. Some members of the public have also reflected that the actual rainfall in their districts was heavier than the aforesaid level, and they are worried that the alert given by the amber signal is not accurate enough. In this connection, will the Government inform this Council:
(a) of the total number of amber signals issued by HKO in the past three years; and when the amber signals were in force, the number of districts among the 18 District Council districts where the actual rainfall exceeded 50 mm in an hour and the respective numbers of flooding reports in various districts;
(b) whether the authorities have considered making reference to the practice of issuing Special Announcement on Flooding in northern New Territories and issuing district-based rainstorm and/or flooding warning to members of the public in selected districts, so as to more accurately alert members of the public that heavy rainstorm is expected soon; and
(c) given that the three-tier rainstorm warning system has been implemented for many years, whether the authorities have considered reviewing the system, including the code of practice at work as well as the arrangements for schools to follow in times of rainstorms?
Our response to the enquiries raised by the Hon Cheung Hok-ming is as follows:
(a) When 30 to 50 mm of rainfall per hour has fallen or is expected to fall generally over Hong Kong, and where the downpour is likely to persist, the Hong Kong Observatory (HKO) will consider issuing the amber rainstorm signal. Since June 2009, the HKO has issued amber rainstorm signals on 36 occasions, excluding those situations that subsequently developed into red or black rainstorm signals. On each of these 36 occasions, about two of the 18 districts on average recorded a rainfall of more than 50 mm per hour (there were seven times where no district recorded a rainfall amount that exceeded that threshold). During these 36 occasions, the Drainage Services Department received a total of 32 flooding reports, 26 of which were from the New Territories. A breakdown is at the Annex.
(b) The northern New Territories has a relatively large water catchment area as well as a flat terrain. Such being the case, it takes a longer time for the rainwater to drain away. The Special Announcement on Flooding in Northern New Territories aims to alert the public that heavy rain may cause flooding in the low-lying areas. In addition to this Special Announcement, the Administration has enhanced the rainstorm warning messages since the rainy season this year, to alert residents in the proximity of watercourses to take timely precautions against any flash floods that heavy rain may cause. The Administration will also continue to examine the feasibility of issuing special announcements on flooding in specific areas.
(c) Apart from raising public awareness in a timely manner, the three-tier rainstorm warning system also ensures a state of readiness among the government departments and service organisations concerned to deal with emergencies. The HKO reviews the arrangements with relevant departments before every rainy season. As regards work and school arrangements, the relevant policy bureau and department have provided the following information:
(i) The Labour Department (LD) has published a "Code of Practice in times of Typhoons and Rainstorms" to provide advice and guidelines to employers and employees on matters such as reporting for duty as well as release from and resumption of work.
The LD will keep reviewing the Code in the light of practical experience so that it meets the needs of both employers and employees.
(ii) The Education Bureau (EDB) has issued circulars to provide schools, parents and students with guidelines on continuation or suspension of classes, students going to school or returning home as well as arrangements on picking-up of students when rainstorm warnings are in force. Every year, leaflets and bookmarks on school arrangements in response to rainstorm warnings are provided by the EDB to schools for distribution to new students for their parents' reference. Before the rainy season, the EDB will also join hands with the HKO in arranging talks for primary school students and their parents in all the districts with a view to explaining the weather warning system and class suspension arrangements under inclement weather. The EDB also reminds schools to issue circular letters to parents and school staff, making sure that they fully understand the above arrangements and the contingency plans of individual schools.
The EDB has revised its guidelines in the light of feedback received. It will continue to draw on experience gained and keep the guidelines under review.
Wednesday, June 6, 2012