CPD Field Excursion – Landslide Visit, Yu Tung Road, Tung Chung (Sat, Feb 6, 2010)
CPD Field Excursion – Landslide Visit, Yu Tung Road, Tung Chung
Lantau Island, Saturday 6 February 2010
Details
Meeting point: Tung Chung, MTR, Exit C.
Time: 9:30 a.m., Saturday 6 February 2010
Duration: The trip will take about 3 hours
Cost: Free of charge (Cost of transportation and lunch not included)
Bring: Plenty of water, sunscreen, mosquito repellant, field-clothing
including strong boots/shoes, wet weather gear as appropriate
Leader: Martin Devonald (Principal Geologist, AECOM Asia Company
Limited)
Overview
The intense rainfall on 7 June 2008 resulted in many landslides on the hillside above the
North Lantau Expressway and Yu Tung Road, Tung Chung. Some of the landslides
developed into channelised debris flows (CDF) while debris from others stopped on the
hillside or simply travelled into a drainage line and washed out as a flood or simply onto
the hillside below.
The consequences of the June landslides were rather severe with a 200 m section of the
North Lantau expressway flooded and completely closed for over 8 hours and both
westbound lanes of Yu Tung Road were blocked and subsequently closed for over two
months from the largest CDF (amazingly caught on video and uploaded to You Tube),
outwash debris also caused flooding of Cheung Tung Road the sole access from Tung
Chung to Discovery Bay.
The purpose of the field visit is to give an overview of two different types of landslide a
channelized debris flow and a debris flood. The site setting, geology and geomorphology
of the hillside and factors affecting landslide magnitude and mobility will be covered.
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The trip will be limited to 15 only with priority given to GSL and IOM members.
The trip will only run in dry weather and note that the trip will pass over some steep
sections of ground.