A QGIS framework for physically-based probabilistic modelling of landslide susceptibility: QGIS-FORM
Citation
Ji, J., Tong, B., Cui, H. Z., Tang, X. T., Hürlimann, M., Du, S. (2025). A QGIS framework for physically-based probabilistic modelling of landslide susceptibility: QGIS-FORM. Environmental Modelling & Software, 183: 106258. Link to paper
Abstract
Earthquake-induced regional landslides frequently result in substantial economic losses and casualties. Conducting landslide susceptibility assessments is essential for mitigating these risks and minimizing potential damage. To address the diverse needs of professionals in various disciplines, an open-source plugin for QGIS, named QGIS-FORM, has been developed. The plugin integrates both a physically-based model (PM) and a physically-based probabilistic model (PPM). The PM employs an infinite slope model incorporating the pseudo-static method, while the PPM utilizes an improved First Order Reliability Method (FORM) to perform landslide susceptibility mapping. The plugin was validated using the Maerkang landslide event in 2022, with susceptibility assessments evaluated using slope, aspect, stratum, and PGA, and the Receiver Operating Characteristic (ROC) curve and Balanced Accuracy employed to assess predictive performance. Study results indicate that landslides in Maerkang are mostly concentrated in slopes between 30° and 50°, and the geological conditions of the Xinduqiao Formation are more prone to landslides. The physically-based probabilistic model exhibits higher accuracy and better identifies potential landslides than the physically-based model, providing more reliable and detailed landslide susceptibility mapping. QGIS-FORM, validated with 2022 Maerkang data, produces reliable and detailed landslide susceptibility zonation.