Recent  

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 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.

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

Water in fractures drive many processes that destabilize steep permafrost-affected rock walls. However, quantitative knowledge on water availability for infiltration is limited. Here we use a numerical model and field measurements to estimate the water balance in a steep rock walls site. We show that snowmelt is the main source of water at elevations >3600 m and that snowpack hydrology and sublimation are key factors. Below 3600 m, surface water availability is increased rapidly due to rainfall.

A novel, artificial intelligence-based riverbed sediment analysis methodology is introduced, which uses underwater images to identify the characteristic sediment classes. The main novelties of the procedure are the followings: underwater images are used; the method enables continuous mapping of the riverbed along the measurement vessel’s route contrary to conventional techniques; cost-efficient; works without scaling.

Planetary surfaces are shaped by both wind and water were their resulting surface features are commonly observed by aerial images. Deep Springs playa, CA provides an comparable wet-to-dry transitioning landscape as experienced in Mars' past. Our results, made through collected weather data and drone footage, showed that some features, when observed solely by aerial imagery might be interpreted as being formed by wind when in fact other processes were more influential in their formation.

The results support that strong scaling relationships exist in both laboratory-scale and field scale submarine canyon-fan systems. We propose that fault slip rate controls the convergence and merging speed of submarine canyon-fan systems, which in turn affects their number and spacing. We further propose a general rule to predict fan volumes by using canyon lengths.

Observations of interaction between extreme physical erosion and chemical weathering dynamics are limited. Here, we presented a major elements of stream water in the badland catchment at 3-hour intervals during a 3-day 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.

We compare models of erosion against a global compilation of long-term erosion rates in order to find and interpret best-fit parameters using an iterative search. We find global signals among exponents which control the relationship between erosion rate and slope, as well as other parameters which are common in long-term erosion modelling. Finally, we analyse the global variability of parameters and find a correlation between precipitation and coefficients for optimised models.

Tectonics and surface processes work together in shaping orogens through their evolution. Laboratory models are used to overcome some limitations of direct observations, since they allow for continuous and detailed analysis of analogue orogens. We use a rectangular box filled with an analog material made of granular materials to study how erosional laws apply and how erosion affects the analogue landscape as a function of the applied boundary conditions (regional slope and rainfall rate).

Extracting paleoenvironmets from sedimentologic/geomorphic records is a main goal in Earth sciences. Thus, we study a chain of processes connecting causative Mediterranean cyclones, coeval floods, storm waves generated by meso-scale funneled wind, and coastal gravel transport. This, in turn, causes northward dispersion of gravel along modern Dead Sea coast, conditions that also have persisted since Late Pleistocene, resulting in beach berms and fan-deltas always deposited north of channel mouths.

High resolution topographic maps have revolutionized our ability to map small-scale features on Earth's surface. Using accuracy metrics from the data sciences, I show that caution is warranted in interpreting pixel-level accuracy scores without also considering scene-level properties. Choosing the right metric and understanding its larger-scale context is needed to properly interpret how good our maps actually are.

Sand dune migration velocity is inversely proportional to dune size. Consequently, smaller, faster dunes can collide with larger, slower, downstream dunes. Such collisions can result in either coalescence or ejection, whereby the dunes exchange mass but remain separate. Our numerical simulations show that the outcome depends probabilistically on the dune size ratio, which we describe through an empirical function. Our numerical predictions compare favourably against experimental observations.

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 pressures) 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-neaps transition.

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

This paper proposes a method for describing large wood behavior in terms of the convection equation and the storage equation, which is associated with active sediment erosion and deposition. Compared to the existing Lagrangian method, the proposed method can easily simulate the behavior of Large wood in the flow field with active sediment transport. The method is applied to the flood disaster in the Akatani river 2017, and the 2-D flood flow computations are succesfully performed.

Straw checkerboard barriers (SCBs) have been widely used in the anti-desertification projects. However, research on mechanism and its laying length are still lacking. The significance of our work is to analyze some results which seemingly simple but lack of theoretical basis from the perspective of turbulence through this model, which may provide the theoretical support for the minimum laying length of SCBs in anti-desertification projects.

The rock glacier in Äußeres Hochebenkar (Austria) moved faster in 2021 than it has in about 70 years of monitoring. It is currently destabilizing. Using a combination of different data types and methods, we show that there have been two cycles of destabilization at Hochebenkar and provide a detailed analysis of related velocity and surface changes. Because our time series are very long and show repeated destabilzation, they help us understand the processes of rock glacier destablization.

In cold regions of the Earth, thawing permafrost can change the landscape, impact ecosystems and lead to the release of greenhouse gases. In this study we used many observational tools to better understand how sediment moves on permafrost hillslopes. Some topographic change conforms to our understanding of slope stability and sediment transport as developed in temperate landscapes, but much of what we observed needs further explanation by permafrost-specific geomorphic models.

We analysed more than 440.000 measurements from the suspended sediment monitoring to show that suspended sediment concentration (SSC) in large rivers in Germany strongly decline by 50 % between 1990 and 2010. We argue that SSC achieves the natural back ground concentrations, due to reduced sediment supply. There is simple explanation for this decline, but effects of reduced supply from headwater streams are most likely the cause for declining SSC in large rivers.