Applicationof electrical resistivity tomography (ERT) method in the evaluation of landslide atthe X urban area project, Da Lat City

Abstract

Landslides frequently occur during the rainy season in mountainous areas of our country with increasing intensity that results in significant loss of life and property. In this research, electrical resistivity tomography (ERT) is used to analyze the structural characteristics of shallow layers and evaluate theirrelationship with the landslide risk at the X urban area in western Da Lat city. Six geoelectrical profiles are carried out by using a four-electrode Wenner-Schlumberger configuration. The results found that the subsurface profile is divided into three layers: layer 1 is completely weathered reflecting a weak soil layer, layer 2 is a semi-weathered layer, and layer 3 characterizes the upper part of the solid rock layer. The fault and water-bearing zones possibly associated with landslide-prone areas are also detected by ERT. Notably, the connection with the current landslide conditions in this area demonstrates that landslides primarily occur in locations with a thick first layer, coinciding with fault zones that potentially contain water. The integrating resistivity results with topographic, geological -geomorphological data, as well as the physical properties of soil and rock collected from geotechnical boreholes,allows us to delineate and forecast landslide potentials of the studied area. The findings indicate that the high-risk zone is concentrated in the southeast of the study area, while the medium-risk zone is scattered in the western region, and the remaining areas are considered to have low potential