Geodetic monitoring of a landslide using conventional surveys and GPS techniques

Many landslides occurred along Amman-Jerash-Irbid Highway in Jordan during its construction in 1991 and 1992. Geological and geotechnical studies were curried out at that time to analyse the problem. This work presents geodetic monitoring of a major landslide on the highway, 6 km to the north of Amman. The importance of this study comes from the need to protect and guarantee the continuity of a major, active highway, which connects the north of the Kingdom to its capital Amman and passes through an unstable and landslide-prone area. For monitoring the landslides in this area we designed a geodetic network, which consists of fifty-six points. Measurements were carried out over a two years period (2002-2004), and GPS receivers and total stations of high precision were used. The measurements were performed annually at two different times, before and after the rainy season. The observations adjustment and the deformation analysis were executed using locally developed computer programs. The study enabled us to determine a value of 0.5 m/year as an average movement of the landslide-prone area.