Search results for "Sediment"

Long-term erosional responses after fire in the Central Spanish Pyrenees

2005

Abstract This paper reports the results of a study on how fire effects water and sediment losses in the Central Spanish Pyrenees where land abandonment results in an increase of the scrubland and fire-affected surfaces. In 1991, two plots (control and burnt) were installed to collect runoff, suspended sediments and solutes. One of the plots was burnt (burnt-1) and the other was covered by shrubs and herbs (control). During 1993, another burnt plot was installed (burnt-2). Data was collected from the three plots until 1999 and is used as the basis for assessing the soil erosion changes after the fire. Runoff, solute and suspended sediment concentration and erosion rates were slightly greater…

Characterizing rainfall erosivity by kinetic power-Median volume diameter relationship

2018

Abstract Kinetic power, i.e. kinetic energy per unit time and area, is the variable widely used to represent the rainfall erosivity which affects soil loss and sediment yield. This paper shows the results of an experimental investigation using the raindrop size distributions (DSDs) measured by an optical disdrometer installed at the Department of Agricultural, Food and Forestry Sciences of University of Palermo in Italy (June 2006–March 2014) and at the El Teularet experimental station in Spain (July 2015–May 2016). At first an analysis of the DSDs aggregated into intensity classes is carried out, then the measured kinetic power values are determined. The aggregated DSDs allowed to establis…

Assessment of drainage network analysis methods to rank sediment yield hotspots

2021

This paper aims to test different methods used for assessing sediment yield indices to identify hotspots and rank sediment yield hotspots. This process includes the assessment of the entropy weight...

Eolian sedimentation in central European Auel dry maar from 60 to 13 ka

2021

AbstractThe climate in central Europe during the last 60 ka is characterized by rapid temperature and moisture changes and strong cold periods (Heinrich events). All these variations are preserved in sediments of marine and also some terrestrial archives. Here we present a continuous, terrestrial sediment record with almost all Greenland stadials and Heinrich events between 60 and 13 ka visible from carbonate roundness of the Eifel Laminated Sediment Archive Dust Stack-20 and CaCO3 data for central Europe. The carbonate roundness data show almost all stadials between 60 and 13 ka. CaCO3 data show a general transport system change with the beginning of Heinrich event 3. Since there are no ca…

Estudio de la tasa de retroceso de una vertiente mediterránea en los últimos 5000 años (Serra del Benicadell, sur del País Valenciano)

1981

Las ramblas valencianas: algunos aspectos de hidrología, geomorfología y sedimentología

1987

Tracing 2000 Years at the Source of the Douix, Côte-d’Or, France: Water, Offerings, and Recurrence

2019

The Source of the Douix in Châtillon-sur-Seine, France, has been visited by local inhabitants for over 2000 years and served as a watery focal point for the ritual deposition of various types of offerings. While water deposits are by no means uncommon across Europe, the continued use of a single space over multiple millennia is. An examination of the preserved offerings at the Douix indicate there are three phases of depositional activity: late Hallstatt to early La Tène periods, late La Tène to Gallo-Roman periods, and the early modern period. Despite being separated by hundreds of years there are similarities across depositional phases including the importance of modified metallic objects…

Taphonomic sequences—A new tool for sequence stratigraphy

2002

The Middle-Upper Jurassic boundary in western Europe is characterized by extensive condensed sections containing authigenic minerals together with abundant and varied fossils, both reworked and not reworked. We have analyzed ammonite shells and chronologically ordered taphonomic events in a taphonomic sequence extending from the time the dead organism settled on the seafloor to the time it became permanently incorporated in the sediment. Three types of taphonomic sequence are recognized; they are characteristic of (1) sedimentation in depositional environments having little and only occasional hydrodynamic activity (coinciding with periods of increasing accommodation), (2) sedimentation dur…

Anthropogenic units fingerprinted by REE in archaeological stratigraphy: Mas d'Is (Spain) case

2013

Abstract On occasions, archaeologists have to deal with serious difficulties to differentiate between processes that ultimately are responsible for the formation of stratigraphic units. Sometimes we face problems related with depositional units in multilayered deposits and other times, we ask for the character of some dark surface soils, very similar to natural paleosols and usually associated with archaeological findings. In both cases, the problems we must address concern the relative impact of human activities. The imbalance between anthropic and natural processes in the formation of archaeological deposits is crucial for a correct interpretation of the processes involved in the formatio…

Growth pattern of underlithified strata during thrust-related folding

2004

Abstract Asymmetric anticlines with overturned or steeply dipping forelimbs and gently dipping backlimbs are generally interpreted as thrust-related folds. Fold asymmetry occurs as a consequence of forelimb rotation. If deformation takes place in environments dominated by submarine sedimentation, the limbs coincide with the slope (depositional surface) and rotation reflects slope steepening. If folds are nucleated in poorly or unlithified deposits, growth geometry also depends on the properties of the media, such as cohesion and the angle of internal friction. For cohesionless deposits, the tilting of the slope influences the equilibrium of the soft sediments, resulting in gravity-driven fl…