# Study on Temporal and Spatial Distribution of Landslides in the Upper Reaches of the Yellow River
## 1 Introduction  
In recent years, due to the influence of global extreme climate events, the frequency of landslide disasters, especially large-scale and extra-large landslide disasters, has become higher and higher [1]. A landslide is a typical mode of surface slope failure and a manifestation of the geomorphological evolution process. It is formed, developed, and evolved under the combined action of geological internal dynamics such as active structure and external dynamic conditions such as climate change [2]. The formation, development, and evolution of landslides are directly or indirectly affected by internal dynamic effects such as crustal uplift [3], fault activity [4], and earthquake [5]. Climate change will have an important impact on topography, hydrological conditions, and river erosion and often trigger the occurrence of landslides [6, 7]. Different experts and scholars have studied the evolution process of landslides by means of landslide spatial form, mutual superposition relationships, and terrace chronology in river valley areas [8; 9; 10; 11; 12]. Among them, [PERSON] et al. [8] analyzed the geological history of the Thompson Valley, then monitored the deformation rate of the landslide using the InSAR measurements and found that most Thompson Valley land-slides exhibit seasonal changes in displacement rate. [PERSON] et al. [9] analyzed the formation mechanism of the reservoir bank landslide with stepped sliding surfaces in the Three Gorges Reservoir area, established a representative geological model with multiple stepped sliding surfaces, and believed that the formation of the stepped landslide surface was closely related to the Jurassic strata with interlayers and weak hard layers. [PERSON] [10] studied the development characteristics of landslides, such as landslide area and landslide volume, through aerial photography and field investigation and established a conceptual model of river cutting, shallow landslides and deep large land-slides driving downslope facing highlands and plateaus. [PERSON] et al. [11] analyzed the geological process of landslide development and river evolution in the Three Gorges Reservoir area of the Yangtze River. [PERSON] et al. [12] studied the response process of landslide development in the upper reaches of the Yellow River to plateau uplift and river incision. Regarding the response relationship between landslide development and geo-morphological evolution in the study area, [PERSON] et al. [13] believed that there may be a relationship between the formation of terraces and the glacial-interglacial climate cycle. The differences in the sequence and age of the Yellow River terraces in the western Henan fault uplift zone and the Huaibei fault depression zone indicate that surface uplift played an important role in the formation of these terraces. [PERSON] et al. [14] studied the geomorphological evolution of the upper reaches of the Yellow River and the uplift process of the Qinghai-Tibet Plateau in the late Cenozoic. This series of plateau uplifts and the Yellow River incised background provide broad space conditions and material sources for the development of landslides in the study area. Based on the measurement and dating of the river terraces, [PERSON] [15] drew the profile of the typical river terraces and analyzed the neotectonic movement of the river terraces in detail. Each tectonic movement developed large-scale geological disasters such as landslides and de-bris flows, and the geological disaster effect was very obvious. At present, research on the spatial and temporal distribution of landslides mainly focuses on the distribution law and inducing factors of landslides in space and time by field investigation, remote sensing interpretation, and dating [16]. [PERSON] et al. [17] collected OSL samples from the sediment covering the landslide and analyzed the absolute age of the landslide. The study suggests that the formation of the Dehenglong landslide is closely related to tectonic activity. [PERSON] et al.