TNAG-1174-FCO40-1476-Proposed-replacement-airport-for-Hong-Kong-at-Deep-Bay-or-Ch-1982 — Page 106

CONFIDENTIAL

5 -

The

At Tsim Bei Tsui, the prevailing wind comes from the sector 020°-

100° (46%).

The proportion of winds from 110°-130° is significantly less than

those at Chek Lap Kok and the existing airport and is probably the result of

the blocking effect of hills over the western part of the New Territories. relatively large percentage of winds from 170°-190° is thought to be the

consequence of the hills in the immediate vicinity of Tsim Bei Tsui (see Fig. 3).

The general direction of airstream in the Deep Bay area is probably southwesterly

during most of the time when southerly wind is reported at Tsim Bei Tsui. The

slightly larger frequency of winds from 290°-310° is similar to the situation at

Chek Lap Kok and could be caused by the land breeze effect during light wind

It may also be to some extent related to the diversion of airflow

conditions.

by hills nearby.

Allowing for the anomalies caused by the exposure of the anemometer at

Tsim Bei Tsui, it would seem that, roughly speaking, about 45-50% of the winds

in Deep Bay are from the sector 020°-100° while about 15-20% come from the

southwest quadrant.

Wind observation in the Zhu Jiang (Pearl River) estuary have been made

by the crews operating the Yau Ma Tei jetfoil service between Guangzhou and Hong

Kong since December 1979. Visual estimates of winds are made twice daily at

around 10 a.m. and 3 p.m. at the following two points: Chuan Bi (Chuen Pi) at

22.7N 113.6E and Da Chan (Tai Shan) at 22.4N 113.8E (Fig. 7).

show the statistics of the wind data which are available. The wind roses are

given in Fig. 8 and 9. At both locations, winds are from east or northeast on

about 40% of the occasions and from south or southwest on about 20% of the

Tables 4 and 5

occasions. This appears to support the estimated figures for Deep Bay in a

broad sense.

CONFIDENTIAL