Understanding Constraints and Triggering Factors of Landslides: Regional and Local Perspectives on a Drainage Basin

Abstract

Abstract:The Grande da Pipa River (GPR) basin (Portugal) has natural conditions that favor the occurrence of landslides. The hydrological year 2009/10 was characterized by high amounts of rainfall, which led to the occurrence of an also high number of landslides in this basin. The hydrodynamic character of the GPR basin was analyzed through a lumped parameter model of daily sequential water balances, in order to understand its influence in the stability of natural slopes. Results from the model were confronted to the inventory of landslides that occurred in the basin during the hydrological year 2009/10. Morphological, geotechnical, and hydrological local conditions affecting slope stability were also analyzed through back-analyses of two selected deep-seated landslides. Data here presented shows that the rise of water table is an important triggering factor for landslides. The most important constraint for landslides in the area is the degree of weathering and thickness of the upper layer of degraded marls. In most of the basin, the degraded layer is less than 5 m deep, causing the occurrence of shallow and intermediate landslides. However, deep-seated landslides were also found in areas, even with degraded marls that were less than 5 m-thick, where landslides have also occurred in the past.

Analysis of landslide explicative factors and susceptibility mapping in an andean context: The case of Azuay province (Ecuador)

“…Therefore, Orejuela and Toulkeridis [ 31 ] give greater weight to precipitation in their study of susceptibility in central Ecuador. However, according to Jesus et al [ 131 ], groundwater rather than precipitation is more critical to triggering a landslide. Groundwater destabilizes the slope, reduces strength, changes density, and generates pore pressures.…”

Assessment of stability of a Himalayan road cut slope with varying degrees of weathering: A finite-element-model-based approach

“…The influence of the alteration of a rock mass on rock engineering parameters has been reported by Everall and Sanislav (2018) . Similarly, Jesus et al. (2018) reported that the strength of a rock formation decreases as the degree of weathering and thickness of the residual-formed soil increases.…”

“…The influence of the alteration of a rock mass on rock engineering parameters has been reported by Everall and Sanislav (2018). Similarly, Jesus et al (2018) reported that the strength of a rock formation decreases as the degree of weathering and thickness of the residual-formed soil increases. Arvanitidis et al (2019) investigated the relationship between the peak friction angle of the soil and the grain size distribution and observed that the effective peak friction angle increases as the coarse-to-fines ratio increases.…”

Analysis of the spatial association of geographical detector-based landslides and environmental factors in the southeastern Tibetan Plateau, China

“…Environmental factors. A total of 12 environmental variables (factors) are used for spatial association analysis in our study, and their basic data are all available in the public domain and may be correlated with geological disasters according to previous studies [11,[43][44][45]. The Shuttle Radar Topography Mission (SRTM) and earthquake data are collected from the Land Processes Distributed Active Archive Center (https://lpdaac.usgs.gov/) and the Earthquake Disasters Program of the USGS.…”