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Loesses are widely distributed all over the world, especially in China. Meanwhile, long-term agricultural irrigation and extreme climate changes have led to frequent geological disasters in the Heifangtai area of Lanzhou, Gansu, China. Of these, landslides are one of the most frequent types of disasters that are harmful to humans and the environment. A landslide is closely related to the lithology, structure, and groundwater of the site and consists of a combination of structure units divided by discontinuities, such as faults, joints, and fissures. Therefore, geological surveys, engineering drilling, and trenching are typically used to identify the stratum lithology, structure, and groundwater in order to visually display underground information within a limited depth range. However, these methods have disadvantages. In particular, geological surveys can only describe geological phenomena on the surface, while the cost of drilling and trenching may be high, along with the inefficiency of exploration. In this research, the integrated geophysical exploration method was used to analyze the hidden joints, cracks, and other discontinuities and geophysical features of the discontinuities. The results were verified by trench exploration, and large amounts of underground information were obtained, especially the spread and distribution of discontinuities in landslide areas. Such information can be effectively used for carrying out and providing meaningful experiences and lessons in future comprehensive geophysical processing and interpretations related to the prediction and evaluation of landslides. [ABSTRACT FROM AUTHOR]

To avoid spatial aliasing problems in broad band high resolution seismic sections, I present a high density migration processing solution. I first analyze the spatial aliasing definition for stack and migration seismic sections and point out the differences between the two. We recognize that migration sections more often show spatial aliasing than stacked sections. Second, from wave propagation theory, I know that migration output is a new spatial sampling process and seismic prestack time migration can provide the high density sampling to prevent spatial aliasing on high resolution migration sections. Using a 2D seismic forward modeling analysis, I have found that seismic spatial aliasing noise can be eliminated by high density spatial sampling in prestack migration. In a 3D seismic data study for Daqing Oilfield in the Songliao Basin, I have also found that seismic sections obtained by high-density spatial sampling (10 × 10 m) in prestack migration have less spatial aliasing noise than those obtained by conventional low density spatial sampling (20 × 40 m) in prestack migration. [ABSTRACT FROM AUTHOR]