Results 61 to 70 of about 424 (174)

Testing the Dry Refuge Model: Paleoecological Insights From Late Pleistocene Gomphotheres in Ecuador

Ecology and Evolution, Volume 16, Issue 8, August 2026.
We present paleontological evidence that may prove the Dry Refuge Model in Ecuador during the Late Pleistocene. ABSTRACT Paleoenvironmental records indicate that Neotropical regions near the Equator experienced reduced rainfall during the Last Glacial Maximum (LGM). However, some records show conflicting environmental signals.
Erwin González‐Guarda, Iván Ramírez‐Pedraza, Carlos Tornero, Lidiane Asevedo, Natalia Villavicencio, Sebastián Escobar, José Luis Román, Melissa Hidalgo, Esteban Benalcázar, Florent Rivals   +9 more
wiley   +1 more source

Flow resistance parameterization for large wood in two‐dimensional depth‐averaged models: Effects of flow condition, blockage, and sediment

Earth Surface Processes and Landforms, Volume 51, Issue 8, August 2026.
Using 16 flume experiments and 2D modeling, we show that large‐wood flow resistance is not a fixed property of wood porosity but varies systematically with flow condition, blockage and most strongly sediment‐shaped bed topography. The drag coefficient and Manning's n are interchangeable, but calibration is essential where scour occurs.
Fikri M. Radiyan, Xiaofeng Liu
wiley   +1 more source

Modelling Flood‐Induced Riparian Vegetation Disturbance and Hydro‐Morphodynamic Feedbacks

Earth Surface Processes and Landforms, Volume 51, Issue 8, August 2026.
A process‐based framework links flood‐induced vegetation disturbance to hydro‐morphodynamic feedback by separating mechanical failure from postfailure outcomes, explaining spatial distribution patterns of washout, burial and localized embankment erosion during the 2019 Chikuma River flood.
Yuexia Zhou, Yuji Toda
wiley   +1 more source

Knickpoint Morphology in Homogenous Substrates Controlled by Sediment Cover and Base‐Level Fall Rate

Earth Surface Processes and Landforms, Volume 51, Issue 8, August 2026.
Knickpoints can form spontaneously under constant forcing, without external perturbations. Flume experiments reveal three distinct morphologies, controlled by the balance between base‐level fall rate and sediment cover. A new conceptual model shows how erosion, sediment armouring and plunge pool dynamics govern knickpoint morphology, challenging ...
William J. Norriss, Edwin R. C. Baynes, John Hillier, Dimitri Lague, Philippe Steer   +4 more
wiley   +1 more source

Flood‐Scale Bedload Transport Dynamics From Acoustic Monitoring Compared With 2D Hydro‐Sedimentary Modeling

Journal of Geophysical Research: Earth Surface, Volume 131, Issue 8, August 2026.
Abstract Accurate estimation of bedload fluxes is critical to understanding sediment transport processes and associated channel evolution in gravel‐bed rivers, however, traditional direct measurements using samplers are time‐consuming and complex. To overcome these limitations, new indirect methods have been developed to estimate fluxes from bedload ...
G. Piasny, P.‐A. Garambois, T. Geay, S. Zanker, L. Schmitt   +4 more
wiley   +1 more source

Experimental Investigation of the Effects of Flow Discharge on the Scour Rate around the Groups of Bridge Piers with a Rough Surface in the Presence of Aggregate Extraction Pits

علوم آب و خاک, 2021
The scour around the bridge piers is one of the main causes of bridge failure and the extraction of aggregates may aggravate this phenomenon. The present study comprehensively investigated the scour around the groups of bridge piers in the presence of ...
R. Daneshfaraz, M. Sattariyan Karajabad, B. Alinejad, M. Majedi Asl   +3 more
doaj  

Experimental study of river morphology downstream of the inclined and vertical grade control structures [PDF]

Journal of Hydraulic Structures
Grade control structure (GCS) can be used to reduce erosion in river beds. They decrease the river bed scour by changing the flow regime and reducing its velocity.
Seyed Mohamad Mahdi Shariati, Mehdi Hamidi   +1 more
doaj   +1 more source

Establishment of a Purge and Trap Continuous‐Flow Isotope Ratio Mass Spectrometer System for Analysis of Stable Nitrate Isotopes (δ15N and δ18O) in Water Samples by Ti(III) Reduction

Rapid Communications in Mass Spectrometry, Volume 40, Issue 14, 30 July 2026.
ABSTRACT Rationale Pollution of surface and shallow groundwater by nitrate (NO3−$$ {\mathrm{NO}}_3^{-} $$) is a global concern, resulting in the deterioration of drinking water quality. Stable isotopes of NO3−$$ {\mathrm{NO}}_3^{-} $$ (δ15N and δ18O) can be used to trace its sources and identify prevailing biogeochemical processes.
Monis Nolitha Gcakasi, Christine Stumpp, Andrea Watzinger   +2 more
wiley   +1 more source

Investigation on local scour downstream of adverse st

Ain Shams Engineering Journal, 2014
This paper is focused on local scour downstream of adverse stilling basins where a submerged wall jet issued from a sluice gate. Experiments were conducted in a wide range of Froude numbers, grain sizes, tailwater depths, and stilling basin slopes.
Javad Farhoudi, Hossein Khalili Shayan
doaj   +1 more source

Application of Artificial Neural Networks in Assessing the Equilibrium Depth of Local Scour Around Bridge Piers

Volume 7: Ocean Engineering, 2015
Scour can have the effect of subsidence of the piers in bridges, which can ultimately lead to the total collapse of these systems. Effective bridge design needs appropriate information on the equilibrium depth of local scour. The flow field around bridge piers is complex so that deriving a theoretical model for predicting the exact equilibrium depth of
Sarshari, Ehsan, Müllhaupt, Philippe
openaire   +2 more sources