A GPR Case Study in The Lodan Dam Area, Rembang of Central Java

A GPR case study has been conducted in the Lodan Dam Area, Rembang, Indonesia. This area is located in a vulnerable area of land movement. The aim of this research is to reconstruct subsurface models which will be related to the distribution of fracture zones and landslides. The data acquisition is performed using a 3D GPR approach. The Lodan Dam area is divided into three segments, the upstream segment, the top of the dam segment, and the downstream segment. The profile results of the three segments use the amplitude response of the rocks. The response to amplitude values indicates the presence of a water-saturated zone. In addition, the GPR data profile of the subsurface model parameters is represented by a pseudo-3D representation. So that can be seen zone saturated water in each profile identify the existence of fracture zones or landslides in the subsurface. The water saturation zone affects the soil load from the crags on the hill. Thus, this existence triggers a crack in the drainage concrete.