Derivation of Stability Equation and Early Warning Value of Landslides on Gentle Piedmont Slopes in the Ningzhen Area of China

Abstract

There are a series of gentle Piedmont slopes with a unique special stratigraphic structure in Ningzhen area of China, which manifest as clay on the surface and the underlying being primarily gravel, exhibiting a binary structure similar to fluvial facies. The number of landslides has increased significantly on gentle Piedmont slopes in this area in recent years due to an increase in extreme rainfall events. Medium to large creeping landslides are dominant, and the sliding surface is between the clay and gravel layers. The main reason is the formation of a water cushion effect due to the unique stratigraphic structure. In this paper, based on previous research, we conducted a model test to verify the influence of the water cushion effect on gentle Piedmont slopes. Meanwhile, we derived a stability equation based on the static equilibrium for gentle Piedmont slopes under three conditions and proposed two methods to derive an early warning value of the pressure head. The rationality of the early warning value was verified by comparing it with measurements. The research results provide important theoretical and technical guidance for early warning and prediction of landslides on gentle Piedmont slopes. The stability equation of landslides is crucial in adequately mitigating hazards, which can provide guidelines for landslide prone areas to avoid hazards in the future. Therefore, landslide warning and prediction is of the utmost significance to ensure the safety of human life, mitigate the negative impacts on the economy, and prevent landslide hazards in gentle Piedmont slopes. Government agencies, policymakers, local authorities, and urban planners can use stability equations and early warning values to plan effective landslide monitoring and prevention measures, and make wise decisions on land-use zoning and development. By identifying areas with high landslide susceptibility through early warning values, constructing buildings and engaging in human activities in hazardous zones can be avoided, reducing the risk of damage and loss during potential landslide events. In addition, landslide warning and prediction play a crucial role in disaster risk management of landslides in gentle Piedmont slopes. Authorities can use these warning values to prioritize areas for early measures. Residents can benefit from the results by being made aware of landslide-prone areas on their property. Consequently, this study is a scientific basis and technical support for the early warning and prediction of landslides on gentle Piedmont slopes in the Ningzhen area, China.