In this study the processes leading to bank failures in the hypertidal Severn Estuary are studied employing numerical models and field observations. Results highlight that the periodic fluctuations in water levels drive an imbalance in the resisting (hydrostatic pressure) versus driving (pore water pressure) forces causing a frequent oscillation of bank stability between stable (at high tide) and unstable states (at low tide) both on semidiurnal bases and in the spring–neap transition.

Sediment transport in rivers is an important matter in Earth surface dynamics. We offer a new framework of understanding of the suspended sediment transport through observatory chronicles and a simple model that is able to catch the behavior during a flood event as well as time series in a steep river catchment. We validate our approach in both tropical and alpine environments, which also offers additional estimates of the size of the suspended sediment.

Alpine rivers have experienced strong changes over the last century. In the present study, we explore the potential of historical multi-temporal elevation models, combined with recent topographic data, to quantify 66 years (from 1953 to 2019) of river changes in the glacier forefield of an Alpine catchment. Thereby, we quantify the changes in the river form as well as the related sediment erosion and deposition.

We simulate the transport of material through numerically simulated river deltas under natural and human-modified (embankment construction and channel dredging) scenarios to understand their impacts on material transport. Human modifications reduce the total area visited by passive particles and alter the amount of time spent within the delta relative to natural conditions. This work can help us understand how future construction may impact land building or ecosystem restoration projects.

This study uses a coastal evolution model to interpret cosmogenic beryllium-10 concentrations and topographic data and, in turn, quantify long-term cliff retreat rates for four chalk sites on the south coast of England. By using a process-based model, clear distinctions between intertidal weathering rates have been recognised between chalk and sandstone rock coast sites, advocating the use of process-based models to interpret the long-term behaviour of rock coasts.

Landslide processes are causes of major concern to population and infrastructures on Réunion. In this study, we used data from the Copernicus Sentinel-1 satellite to map ground motion in Cirque de Salazie. We concentrate on the cyclonic season 2017–2018. Our results show ground motion in the Hell-Bourg, Ilet à Vidot, Grand-Ilet, Camp Pierrot, and Le Bélier landslides. Moreover, we show an unknown pattern of ground motion situated in a non-instrumented, uninhabited area on the ground.

We explore the relation between the spatial patterns of rainfall return levels for various timespans (1–72 h) and landslide density during a rainfall event that triggered widespread landslides. We found that landslide density increases with increased rainfall return levels for the various examined timespans. Accordingly, we conclude that whether rainfall intensities reached exceptional return levels for a wide time range is a key determinant of the spatial distribution of landslides.

Observations of the interaction between extreme physical erosion and chemical weathering dynamics are limited. We presented major elements of stream water in the badland catchment at 3 h intervals during a 3 d typhoon. The excess sodium in the evaporite deposits causes material dispersion through deflocculation, which enhances the suspended sediment flux. Moreover, we observed a shift from predominantly evaporite weathering at peak precipitation to silicate weathering at peak discharge.

Various models have been used in science and practice to estimate how much large wood (LW) can be supplied to rivers. This contribution reviews the existing models proposed in the last 35 years and compares two of the most recent spatially explicit models by applying them to 40 catchments in Switzerland. Differences in modelling results are discussed, and results are compared to available observations coming from a unique database.

We investigated the mineral content and geochemical composition of the upper 6 m of regolith, formed by weathering of granitic rocks in Mediterranean and humid climate zones. We found that the development of the upper regolith in the Mediterranean climate is controlled by secondary minerals which cause fracturing and thus facilitate fluid infiltration to depth. The upper regolith in the humid climate is controlled by secondary minerals that cause a reduction of fluid infiltration to depth.

This study presents a method to calculate the volume of rock eroded by the sea on volcanic islands, by reconstructing their pre-erosion shape and size. The method has been applied on Corvo Island (Azores). We show that before the island was eroded, it was roughly 8 km wide and 1 km high. The island has lost more than 6 km³ of rock and 80 % of its surface. We also show that the erosion of sea cliffs is mainly due to the moderate and most frequent waves.