Preprints
Filtering by Subject: Geomorphology
Suspended-sediment induced stratification inferred from concentration and velocity profile measurements in the lower Yellow River, China
Published: 2020-01-27
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Sedimentology
Despite a multitude of models predicting sediment transport dynamics in an open-channel flow, the interaction between fluid and sediment, so to produce self-organized vertical density stratification, has not been robustly investigated and as such is poorly understood. This two-phase phenomenon develops in channels that possess low channel-bed slope and high sediment concentration. As the Yellow [...]
Rainsplash Erosion for Natural Slopes and Rainfall Conditions
Published: 2020-01-24
Subjects: Earth Sciences, Environmental Sciences, Geomorphology, Physical Sciences and Mathematics
Rainsplash is significant for interrill erosion since it facilitates the movement of loosened soil frangments. Because it is a technically dicult process to measure, many studies focus on experimental simulation under controlled conditions both in field and laboratory. Raindrop erosion studies have produced models to predict the erosivity due to raindrop impact on varying ground surfaces, with a [...]
Hydro-morphodynamics 2D modelling using a discontinuous Galerkin discretisation
Published: 2020-01-09
Subjects: Applied Mathematics, Computer Sciences, Earth Sciences, Geomorphology, Numerical Analysis and Computation, Partial Differential Equations, Physical Sciences and Mathematics, Sedimentology
The development of morphodynamic models to simulate sediment transport accurately is a challenging process that is becoming ever more important because of our increasing exploitation of the coastal zone, as well as sea-level rise and the potential increase in strength and frequency of storms due to a changing climate. Morphodynamic models are highly complex given the non-linear and coupled nature [...]
Impact of nested moisture cycles on coastal chalk cliff failure revealed by multi seasonal seismic and topographic surveys
Published: 2020-01-09
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Cliff failure is a fundamental process shaping many coastlines worldwide. Improved insight into direct links between cliff failure and forcing mechanisms requires precise information on the timing of individual failures, which is difficult to obtain with conventional observation methods for longer stretches of coastline. Here we use seismic records and auxiliary data spanning 25 months to [...]
Landscape variables in the Indian (Peninsular) catchments: insights into hydro-geomorphic evolution
Published: 2020-01-02
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
The river systems in peninsular India are remained unexplored in terms of hydro-geomorphic evolution, though a few works are carried out in order to understand the tectonic and structural evolution with paleoclimate. Morphometric analysis at catchment scale delivers insights into the dynamics, erosion capacity, probability of flood occurrence, lithological and structural control, and genetic [...]
Active deformation and Plio-Pleistocene fluvial reorganization of the western Kura Fold-Thrust Belt, Georgia: implications for the evolution of the Greater Caucasus mountains and seismic hazard
Published: 2019-12-31
Subjects: Earth Sciences, Geology, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
Since the Plio-Pleistocene, southward migration of shortening in the eastern part of the Greater Caucasus (GC) into the Kura foreland basin has progressively formed the Kura-Fold Thrust belt (KFTB) and Alazani piggyback basin, which separates the KFTB from the GC. Previous work argued for an eastward propagation of the KFTB, implying that the western portion in Georgia is the oldest, but this [...]
Four-dimensional surface motions of the Slumgullion landslide and quantification of hydrometeorological forcing
Published: 2019-12-09
Subjects: Earth Sciences, Geomorphology, Geophysics and Seismology, Other Earth Sciences, Physical Sciences and Mathematics
Landslides modify the natural landscape and cause fatalities and property damage worldwide. Quantifying landslide dynamics is challenging due to the stochastic nature of the environment. With its large area of ~1 km2 and perennial motions at ~10-20 mm per day, the Slumgullion landslide in Colorado, USA, represents an ideal natural laboratory to better understand landslide behavior. Here, we use [...]
Climate driven Holocene erosion in central Ukraine
Published: 2019-12-04
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
The younger Quaternary erosion history was reconstructed in a catchment close to the Chalcolithic giant settlement Maidanetske, central Ukraine based on dated sediment sequences. Four trenches and a long percussion drill-core were analyzed in a valley grading from a Loess covered plateau towards the Talianky River. The sediments were dated via a combination of radiocarbon dating, optical [...]
Dreibrodt et al.- Holocene erosion history in central Ukraine
Published: 2019-12-04
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
The younger Quaternary erosion history was reconstructed in a catchment close to the Chalcolithic giant settlement Maidanetske, central Ukraine based on dated sediment sequences. Four trenches and a long percussion drill-core were analyzed in a valley grading from a Loess covered plateau towards the Talianky River. The sediments were dated via a combination of radiocarbon dating, optical [...]
Optical wave gauging using deep neural networks
Published: 2019-12-04
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Geomorphology, Physical Sciences and Mathematics
We develop a remote wave gauging technique to estimate wave height and period from imagery of waves in the surf zone. In this proof-of-concept study, we apply the same framework to three datasets: the first, a set of close-range monochrome infrared (IR) images of individual nearshore waves at Duck, NC, USA; the second, a set of visible (i.e. RGB) band orthomosaics of a larger nearshore area near [...]
Logjams are not jammed: measurements of log motions in Big Creek, Idaho
Published: 2019-11-08
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
Colloquially, a "logjam" indicates a kinematic arrest of movement. Taken literally, it refers to a type of dense accumulation of wood in rivers widely recognized as bestowing numerous biological and physical benefits to the system but also present serious hazards to infrastructure. Despite this, no in-situ field measurements have assessed the degree of arrest in a naturally-formed logjam. Using [...]
Chemical versus mechanical denudation in meta-clastic and carbonate bedrock catchments on Crete, Greece, and mechanisms for steep and high carbonate topography
Published: 2019-11-05
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics
On Crete — as is common elsewhere in the Mediterranean — carbonate massifs form high mountain ranges whereas topography is lower in areas with meta-clastic rocks. This observation suggests that differences in denudational processes between carbonate-rich rocks and quartzofeldspathic units impart a fundamental control on landscape evolution. Here we present new cosmogenic basin-average denudation [...]
PYRENAIC ROCK GLACIERS: AN AIRBORNE AND MULTITEMPORAL LiDAR MONITORING CASE STUDY IN THE BESIBERRI AREA
Published: 2019-10-24
Subjects: Earth Sciences, Environmental Sciences, Geology, Geomorphology, Glaciology, Physical Sciences and Mathematics
The monitoring of rock glaciers is a current subject of interest because of its application as permafrost indicator and its sensitivity to climatic changes (especially temperature and precipitation). Alpine rock glaciers in the Pyrenees have been described by various authors, but to study them regionally has been a challenge since most of these studies are based on ground-based techniques. Two [...]
Rock strength and structural controls on fluvial erodibility: implications for drainage divide mobility in a collisional mountain belt
Published: 2019-10-13
Subjects: Earth Sciences, Geomorphology, Physical Sciences and Mathematics, Tectonics and Structure
Numerical model simulations and experiments have suggested that when migration of the main drainage divide occurs in a mountain belt, it can lead to the rearrangement of river catchments, rejuvenation of topography, and changes in erosion rates and sediment flux. We assess the progressive mobility of the drainage divide in three lithologically and structurally distinct groups of bedrock in the [...]
Lower threshold for marsh drowning suggests loss of microtidal marshes regardless of sediment supply
Published: 2019-10-10
Subjects: Earth Sciences, Environmental Sciences, Geomorphology, Natural Resources and Conservation, Physical Sciences and Mathematics
Salt marshes are simultaneously among the most valuable and vulnerable ecosystems in the world. We use a simplified formulation for sediment transport across marshes to explain why marshes are most vulnerable to sea level rise (SLR) in microtidal environments. We find inorganic sediment decay length scales with tidal range so that inorganic deposition is very low in the interior of microtidal [...]