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Soil erosion is the major environmental risk that causes topsoil loss, which decreases fertility in agricultural land. Spatial estimation of soil erosion is essential for conserving land resources and for developing control plans. This study evaluated soil erosion in 17 sub-basins of the Wadi Hanifa catchment using the Gavrilović model. The soil erosion rate is categorized into three classes based on the annual volume of rainfall and runoff. About 21% of the drainage area of Wadi Hanifa is affected by erosion severity, and 33% of the area is affected by severe erosion. The correlation obtained between the annual soil erosion and annual volumes of rainfall and runoff is significant. It is concluded from the results that the drainage area of the north-western part suffers from a high soil erosion risk. The NRCS-CN and erosion predict that the Gavrilović model can be applied for estimating and analyzing the spatial distribution of soil erosion over more drainage watersheds in Saudi Arabia. Now, the GIS techniques are one of the best tools for developing the conservation and management planning processes of soil resources.

Estimating the density interface depth is an important task when interpreting gravity data. A range of techniques can be applied for this. Here we compare the effectiveness of the wavenumber and spatial domain techniques for inverting gravity data with respect to basement reliefs. These techniques were tested with two synthetic gravity models, and then applied to a real case: the gravity data of the Magura basin (East Slovakian Outer Carpathian). The findings show that the spatial domain technique can precisely estimate the structures, but the computation speed is slow, while the wavenumber domain technique can perform faster computations with less precision.

In this study, we investigated the stability and reactivation of preexisting Tonghua landslide deposits in China, including the adjacent stable slope. We used an integrated approach, combining a multichannel analysis of surface waves (MASW) and electrical resistivity tomography (ERT). We used ERT to determine groundwater seepage paths, weathering conditions, water content, and the depth to bedrock. High-resolution two-dimensional (2D) shear-wave velocity MASW images, on the other hand, played an essential role in detecting both horizontal and vertical compositions, disjointedness, and sliding surfaces related to lithological borders. Based on seismic models, we considered four geological layers encountered in the stable slope, including fractured (gravel) and weathered (phyllite) materials, as a sliding mass. We combined the 2D resistivity profiles obtained to create pseudo-three-dimensional ERT images to estimate water-saturated and unsaturated masses. From the tomography results, we identified different preexisting deposits, including buried arable clay deposits, old accumulated earthflow deposits, a water accumulation zone, and a fissure runoff. Based on the resistivity results, the bottom of the earthflow deposits is susceptible to water, and oversaturation can reactivate the earthflow.

The physical, geochemical, and clay mineralogical properties are location dependent and influence landslide, yet this relationship is understudied in the Cameron Highlands. Therefore, this study demonstrates the effect of the selected physical–geochemical properties and clay mineralogy on landslide susceptibility (LS) in the Cameron Highlands, Malaysia. Seven soil samples were taken from non-landslide-affected slopes (NAS) and 13 from landslide-affected slopes (LAS), making a total of 20 samples that were analyzed. The degree of the LAS and NAS ranges from 42–80° and 30–70°, respectively. The NAS soils were characterized by lower sand, higher clay, higher organic matter content (OMC), and higher cation exchange capacity (CEC). Soils with high sand tend to have larger free pores and weak bonds, making them more vulnerable to landslides. The electrostatic charges on the clay’s surface bind the solution ions, increasing cohesion between soil particles. Also, high CEC in soils improves their stability through the binding effect resulting from the attraction between solution ions via the electrostatic surface charges of the clay in the soil. The clay mineralogy revealed the abundance of kaolinite and illite, indicating the last stage of weathering associated with the weathering of primary minerals forming the bedrock. In this study, it was demonstrated that high sand, low clay, low OMC, low CEC, and clay mineralogy of the soil were associated with slope failure in the study area.