Evaluating the performance of GPS survey methods for landslide monitoring at hillside residential area: Static vs rapid static

Abstract

The landslide is considered as one of the worst natural disaster that continuously affecting many tropical countries, especially during the monsoon season. Landslides bring destructiveness and various losses to the human living. For the past 25 years, many rainfall induced landslides have occurred throughout our country that strikes the citizens, especially near the hillside areas whereby several properties damaged, human deaths and injured had been reported. Landslide monitoring scheme is therefore very crucial and should be done continuously. Various studies have been conducted to monitor the landslide activity using many approaches, such as classical geotechnical and geodetic surveying method. Each of these approaches posed their own advantages and limitations. This study discusses the effectiveness of satellite tracking data in landslide monitoring. This project area located at Section 5, Wangsa Maju, Kuala Lumpur. The monitoring network consists of four (2) control points namely M01 and G01, and eleven (11) monitoring. Five GPS surveys involving 11 GPS points have been conducted, namely 1st epoch - May 2005, 2nd - November 2005, 3rd epoch - May 2006, 4ft - November 2006 and 5ft - May 2007, respectively separate by using two GPS observation modes such as static (1st,2nd and 3rd epoch) and rapid static (4ft and 5ft epoch) mode. The results of GPS surveys show that the magnitudes of land movements in the study area vary from mm to cm level, depending on the location and the observatiuon period in relation with rainy and dry season. The paper will also discuss the constraints faced by GPS survey method in the landslide prone area environment, which is usually hilly and sloping sharply.