# Development Pattern of Toppling Deformation Slopes in Western China
## 3 Regional Geological Susceptibility
### Selection of Factors  
To study the features of toppling deformation development and reveal the connection between distribution and regional geological background, taking the relative basic data we had into consideration, four typical regional geological factors were identified:  
1. Landform type can provide information on the size and scale of landform features and how this size and scale might affect the amounts of energy available for geomorphic, pedogenic and hydrological processes. Landform types provide context that can be used to inform and improve the further sub-division of the landscape into landform elements [78], and thus can be used for further research on the development of toppling deformation. 2. Stratigraphic age can reflect the geological history and has important guiding significance for the study of slope stability and deformation mechanisms. The rock properties, structural characteristics and depositional environment of different stratigraphic ages may affect the stability and deformation characteristics of the slope. At the same time, the physical properties of rocks in different ages are different, including density, compressive strength, shear strength, etc. These factors will affect the stability of the slope. In the division of stratigraphic age, there are certain contact surfaces and contact zones between different rock layers. The geomechanical characteristics of these areas are among the main sources of slope instability and deformation. 3. Seismic intensity is considered a typical regional geological factor when analyzing the regional geological distribution law of toppling deformation development, because strong geological tectonic activity can cause significant ground shaking, which can trigger landslides and other types of ground instability. Seismic activity can also affect the strength and stability of rock formations, leading to toppling deformation. Therefore, understanding the seismic history and potential for future seismic activity is critical when assessing the risk of toppling deformation in a particular region. Seismic intensity is a quantitative measure of the level of ground shaking that occurred during past earthquakes and can be used to estimate the potential for future seismic events in the area. By analyzing seismic intensity data along with other geological factors, such as slope angle and dip angle, the regional geological distribution of the toppling deformation development can be better understood. 4. Tectonic stress distribution is a typical regional geological factor when analyzing the regional geological distribution law of toppling deformation development because tectonic forces play a significant role in shaping the Earth's surface. Tectonic stresses can lead to the development of geological structures such as faults, folds and joints, which can affect the stability of rock formations and increase the risk of toppling deformation. In regions affected by high tectonic stress, such as those located near active fault zones, the likelihood of rock mass instability induced by tectonic stress increases, and the depth of slope toppling deformation significantly increases [55]. By studying the distribution of tectonic stress in a region, areas with higher risk of toppling deformation can be identified, which can further our understanding of the features of toppling deformation development. The above four factors were chosen to analyze the regional geological distribution regularity of the toppling deformation slopes. The line from the Altun Mountains to the Yinshan Mountains and the area from latitudes 25\({}^{\circ}\) to 38\({}^{\circ}\) N in China were chosen as the study zones.