An increasing number of studies demonstrates links between the intensity of periglacial processes and bedrock erosion in steep mountain landscapes. Here, we quantify the dependence of periglacial processes on temperature and sediment thickness. This allows us to model frost processes across the full range of settings encountered in mountain landscapes. We find that sediment mantle thickness strongly modulates the relation between climate and periglacial weathering and sediment transport.

We incorporate relations between climate, sediment thickness and periglacial processes quantified in the accompanying paper into a landscape evolution model. This allows us to time-integrate the periglacial contribution to mountain topography on million-year time scales. It is a robust result of our simulations that periglacial processes lead to topographic smoothing. Owing to the climate dependency, this smoothing leads to formation of low-relief surfaces at altitudes controlled by temperature.

Rock is exposed at the Earth surface when erosion rates locally exceed rates of soil production. This transition is marked by a diagnostic increase in topographic roughness, which we demonstrate can be a powerful indicator of the location of rock outcrop in a landscape. Using this to explore how hillslopes in two landscapes respond to increasing erosion rates, we find that the transition from soil-mantled to bedrock hillslopes is patchy and spatially heterogeneous.

Large earthquakes commonly trigger widespread and destructive landsliding. This paper tests the hypothesis that spatial distributions of earthquake-induced landslides are determined by both the conditions at the time of the triggering earthquake and the legacy of past events. Our findings emphasise that a lack of understanding of the legacy of damage in hillslopes potentially represents an important source of uncertainty when assessing regional landslide susceptibility.

The paper assesses bedload transport in a formerly glaciated high-mountain basin by means of a virtual velocities approach. Virtual velocities were derived by surveying tracers movement over a 3-year study period. Tracers were deployed in two contrasting sites, a fluvially dominated hanging valley and a downstream relict glacial trough where periodic colluvial sediment inputs from tributaries are experienced. We also investigate contribution given to bedload transport by rainfall and snowmelt.

Block and boulder fields record catastrophic coastal flooding events and play a pivotal role in coastal hazard assessment. After Supertyphoon Haiyan on 8 Nov 2013 the transport of extremely large blocks of up to 180 t in E Samar (Philippines) was documented, indicating that hydrodynamic conditions induced by tropical cyclones, including infragravity waves, and resulting coarse-clast transport patterns may be comparable to tsunamis.

We compiled data on Alpine glacial lake morphometry to test empirical relationships that are used to estimate lake volume for the modelling of glacial lake outburst floods. We find wide scatter in the relationship between lake area and depth, and between area and volume, and identify contexts where existing empirical relationships are poor volume predictors. We generate a data-driven conceptual model of how lake volume should be expected to scale with area for a range of glacial lake contexts.

A physical scale model of a gravel-bed braided river was used to measure vertical grain size sorting in the morphological active layer defined as the bed material between the maximum and minimum bed elevation. By normalizing active layer thickness and dividing into 10 sublayers we show that all grain sizes occur with almost equal frequency in all sublayers. Occurrence of patches and strings of coarser material relates to preservation of particular morphotextural features within the active layer.

How good are measurements of shapes in the landscape? This is not well constrained. We suggest that "synthetic tests" using constructed digital landscapes called synthetic DEMs are a powerful and necessary tool to establish the reliability of these data (e.g. mapped sizes). Thus, the tests have a key, complementary role in determining if conceptual and physics-driven models of processes can be reconciled with morphological observations of reality. A typology of synthetic DEMs is proposed.