XN000022-1995-03-28 — Page 21

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Dr Choi said detailed hydraulic studies had been conducted by the government to ensure that the hydraulic conditions, both during and after the construction of major port developments, and large-scale reclamations would suit waterborne activities.

"The studies using a suite of advanced mathematical and physical models to find out the effects of harbour engineering works on tidal flow regime, wave climate and sediment deposition characteristics, have helped to select the optimum layouts of these proposed developments," he said.

He pointed out that the department had conducted over 30 hydraulic studies for major port developments since 1989. Of these, the most representative ones were the West Kowloon Reclamation, the Central Reclamation and the Green Island Reclamation in Victoria Harbour and the Lantau Port Development.

"It is found that upon the completion of the three reclamation projects in the Victoria Harbour, the peak current velocity between Central and Tsim Sha Tsui will be reduced by 12% while in other areas the current velocities will be basically unchanged.

"The result of an in-depth hydraulic study for the Lantau Port Development which involves about 1,000 hectares of reclaimed land and the construction of a five- kilometre long breakwater between Lamma Island and Cheung Chau, has indicated that upon the completion of the development, there will be little change to the tidal flow in the Victoria Harbour.

"On the other hand, the development will provide a more even distribution of the tidal flow in the western part of the harbour, resulting in better control of water quality.

"The increase of flow in East Lamma Channel is expected to be about six per cent. Therefore, it can be concluded that the Lantau Port Development does not have significant effect on navigation and other waterborne activities.

"The Lamma Breakwater will have a significant effect on the wave climate of the Western Harbour where an anchorage will be developed.

"The percentage of time during which wave height at the proposed anchorage exceeds 0.75 metre will be reduced from about 9.5% to about 1.8%, representing a substantial improvement to vessel safety," Dr Choi said.