An ecological indicator system for shallow landslide analysis

Ecological factors are important for shallow landslide risk assessment. Various ecological indicators have been previously proposed and studied. However, because the functional mechanisms of plants on shallow slope stability are very complex, a well-organized ecological indicator system that can reflect the effects of ecology on shallow slope stability is still absent, which in turn restrains the consideration of ecological factors in shallow landslide analysis. This paper proposes a new ecological indicator system for shallow landslide analysis based on a comprehensive survey of existing ecological indicators. Firstly, existing ecological indicators are summarized with regarded to the three major types of effects of vegetation on shallow slope stability (i.e., geotechnical mechanics effect, soil-hydrological effect, and interception and stemflow effect), so that the functional mechanisms of plants on slope stability are reflected. Then, all ecological indicators are grouped into the three fundamental ecological element categories (i.e., ecological attribute, ecological structure and ecological function) to constitute the new ecological indicator system. This re-organization, by eliminating redundancy, makes the new ecological indicator system more well-structured and more applicatory in practice. Finally, some issues regarding the application of the new indicator system are discussed. It is particularly recommended to consider the possible negative effects, the applicable spatial scale of specific ecological indicators, and the preferred application of ecological structure indicators. The new ecological indicator system is expected to facilitate the consideration of ecological factors in landslide risk assessment.