The Ebbabreen ice−cored moraine area is covered with a sediment layer of up to 2.5 m thick, which mostly consists of massive diamicton. Due to undercutting by lateral streams, debris flow processes have been induced in marginal parts of this moraine. It was recognized that the sedimentology of deposits within the deposition area of debris flows is the effect of: (1) the origin of the sediments, (2) the nature of the debris flow, and (3) post−debris flow reworking. Analysis of debris flow deposits in microscale (thin sections) suggests a common mixing during flow, even though a small amount of parent material kept its original structure. The mixing of sediments during flow leads to them having similar sedimentary characteristics across the deposition area regardless of local conditions ( i.e. slope angle, water content, parent material lithology). After the deposition of sediments that were transported by the debris flow, they were then reworked by a further redeposition process, primarily related to meltwater stream action.

The basic characteristics of debris flows in the Shiwei river basin are summarized through the field investigation on debris flows in the Shiwei river basin and analysis on formation conditions of debris flows from three aspects, i.e. geological environment, geological structure and neotectonic movement, as well as seismic action. Based on this, the stability of landslide in the Shiwei river basin is analyzed and calculated, and the stability coefficient of landslide is obtained. The debris flows in the Shiwei river basin will directly damage and threaten the county town, while other geological disasters such as landslide, collapse, slope sliding & collapse and potentially unstable slopes will indirectly damage and threaten the county town. The landslide form is clear, and the landslide stability calculation shows that the landslide body is generally stable – basically stable, but partially unstable – less stable. The “blocking + discharging” comprehensive control scheme is proposed according to the formation conditions and development characteristics of debris flows in the Shiwei river basin, and the study findings can be used as a reference for similar projects.

Evidence of recent geomorphic processes within debris cones, their spatial distribution and diversification on cones surface are interpreted in the context of contemporary slope morphogenesis. The detailed inventory of relief features on debris cones in the SW Spitsbergen revealed their great spatial diversity. It is linked with a dominance of different morphological processes in adjacent areas. Spatial and temporal diversity of process-relief assemblages on cones is strongly related with local factors, like bedrock lithology, slope aspect and inclination, local circulation and climatic conditions. However, the potential role of debris cones and their topographic features as geoindicators archiving information about the environmental impact of global changes, cannot be explicitly estimated. Local constraints obscure the regional expression of any global trends, which could be detected on the basis of process-relief assemblages on debris cones in polar regions.

The Matmata region, located in the south of Gabès (Tunisia), experienced significant damage during the floods of the Beni zelten wadi on November 11, 2017. These floods, exacerbated by the steep slopes and underlying soil conditions, led to the occurrence of debris flows, posing a threat to road infrastructure. The generation of debris flows is closely linked to intense rainfall events that surpass the soil capacity to retain water. To gain insights into the behaviour of the soil samples, various characteristics were analysed, including texture, clay mineralogy, grain size distribution, and Atterberg limits. The results showed that the mean liquid limit values ranged from 38% to 62%, while the mean plasticity index of the materials in the landslide-prone areas varied from 18% to 27.9%. These findings indicate presence of clay formations and highlight a significance of the increased soil clay content as contributing factors to landslide development. The X-ray Diffraction analysis revealed that gypsum, quartz, phyllosilicate and calcite minerals were the most abundant minerals identified in the soil samples. This work shows the importance of clay mineral and geotechnical parameters of the soils in the occurrence of landslides and predicting debris flows occurrences in the Matmata region.

The Slyngfjellet Conglomerate which occurs at the base of the Upper Proterozoic Sofiebogen Group in South Spitsbergen had formed predominantly as a debris-flow deposit, with subordinate contribution by fluvial and probably lacustrine sediments. There is no evidence for glacial conditions at the time of formation of the conglomerate, the latter being much older than the latest Proterozoic Varangian glaciation tillites elsewhere in Svalbard. The Slyngfjellet Conglomerate originally filled buried valleys eroded by rivers in block-faulted and uplifted western margin of the Mid-Proterozoic Torellian Basin.