Characteristics of Sedimentary Structure of Mekong and Saigon River Banks by Geophysical and Geological Data

Abstract

The complex of GPR,VLF, Electrical Imaging and engineering wells were used for sedimentary structure investigating on banks of Mekong and Saigon rivers. The geophysical data were collected by PulseEkko 100, VLF Wadi and Terrameter SAS 300C/4000 and interpreted by winekko pro., sector for 20 km profiles which carried out along and across Tien river banks and 12 km profiles which carried out along both sides of Saigon river banks. The weakness zones or fructures or holes which were located by geophysical anomalous are proved by engineering wells with different depths. The sedimentary structure of river banks is presented by geological sections with unhomogenous and anisotropic medium. The high resistivity on the geoelectrical section is corresponding to sand material and the low resistivity to silt and saturated clay. The morphology of river bottom is determined by GPR cross-section where the main Tien river flow is near right side with 17 m of depth and the main Saigon river flow is near left side with 13 m of depth. On the basis of geophysical investigation and engineering wells we can forecast of landslides for Tien river banks ( right side – Sadec town) and Saigon river banks for near future.