Assessment of the Environmental Impacts of Landslides on Groundwater Resources Using Geoelectrical Surveys and Dipole-Dipole Arrays

The present study aimed to assess the geological impacts of landslides on groundwater resources along the Shemshak-Dizin road, Iran, using the geoelectric geophysical method based on a dipole-dipole array. Thus, five geoelectric acquisition profiles were designed and implemented to identify the landslide geometry and assess its impacts on the regional groundwater system. The results of reverse modeling showed the clear boundary of the landslide layers and the areas with high humidity, as well as the lithological facies and the local water infiltration through fractures downstream of the landslide. The comparative results of the quantity of groundwater at present with those of the previous year show that the groundwater level in this area has decreased by an average of 14 meters compared to 2010. In addition, due to the destruction of vegetation, the penetration of surface water caused by rainfall into the soil has decreased, which has had a negative impact on the occurrence of landslides. The results showed that the penetration of water caused by rainfall in the study area in 2010 was about 64 percent, which decreased in 2023 owing to the destruction of vegetation and reached about 55 percent. Factors such as slope, altitude, rainfall, distance to fault, and land use were effective in the occurrence of landslides in the study area. On the other hand, the regional groundwater had no direct or positive impact on landslides. However, landslides in the area had caused the groundwater level to drop. Destruction of vegetation was one of the factors affecting this phenomenon.