Southern Thailand was subjected to an intense rainfall in November, 1988. This rainfall triggered thousands of slope failures in the Khao Luang Mountain Range and caused widespread flooding in southern Thailand. The landslides, debris flows and flooding caused the deaths of 370 people and damage to properties estimated at about US$ 300 million. Landslides and debris flows are expected in the Khao Luang Mountain Range because of the disturbed slope materials, land-use pattern, intense seasonal rainfall and the geomorphic development in the area. This paper investigates the mechanism of debris flow initiation in the Lham Nah Creek Basin (Study Area) in the Khao Luang Mountain Range by analysing the properties of materials involved in debris flows.
Southern Thailand, particularly the Khao Luang Mountain Range, was subjected to an intense rainfall during the period 19th to 23rd November, 1988. This rainfall triggered thousands of slope failures in the Khao Luang Mountain Range and caused widespread flooding in southern Thailand. The landslides, debris flows and flooding caused the deaths of 370 people and damage to properties estimated to be in the order of US$ 300 million (HANSON, 1989). The location of the Khao Luang Mountain Range, rivers emanating from the mountain range and places severely effected by landslides and debris flows during November 1988 storm are shown in Figure 1. Landslides and debris flows are expected in the Khao Luang Mountain Range because of the disturbed slope materials, land-use pattern, intense seasonal rainfall and the geomorphic development in the area (HANSON, 1989). If adequate mitigative measures are not implemented, the casualties and cost of possible future landslides and debris flows are likely to be very high. The risk is increased because of population growth and economic developments in the area.
