High natural erosion rates are the backdrop for present-day soil erosion in the agricultural Middle Hills of Nepal
Summary: Soils are vital resources put at risk by erosional loss. Evaluating agricultural effects on erosion is complicated where natural rates are high, as in central Nepal. This study infers erosion rates over thousands of years and compares these rates to those observed over the short term. Results suggest that effects of agriculture are small and that most erosion takes place through natural processes. However, present-day erosion on degraded lands is significantly faster than over the long term.
Earth Surf. Dynam., 3, 363-387, doi:10.5194/esurf-3-363-2015, 2015
Sensitivity analysis and implications for surface processes from a hydrological modelling approach in the Gunt catchment, high Pamir Mountains
Summary: A semi-distributed hydrological model is used to analyse the hydrological cycle of a glaciated high-mountain catchment in the Pamirs. We overcome data scarcity by utilising various raster data sets as meteorological input. Temperature in combination with the amount of snow provided in winter play the key role in the annual cycle. This implies that expected Earth surface processes along precipitation and altitude gradients differ substantially.
Earth Surf. Dynam., 3, 333-362, doi:10.5194/esurf-3-333-2015, 2015
Morphology of the Kosi megafan channels
Summary: This study mainly focused on the comparison between braided river channels and meandering river channels. We show that the morphology of braided and meandering channels are comparable and their width, depth and slope scale in same way against water discharge. This is the key finding of our study and it has never been tested before.
Earth Surf. Dynam., 3, 321-331, doi:10.5194/esurf-3-321-2015, 2015
The role of log jams and exceptional flood events in mobilizing coarse particulate organic matter in a steep headwater stream
Summary: The export of coarse particulate organic matter (CPOM) from mountain catchments seems to be strongly linked to rising discharge, but the mechanism leading to this is unclear. We show that log jams in a steep headwater stream are an effective barrier for CPOM export. Exceptional discharge events play a dual role: First, they destroy existing jams, releasing stored material. Second, they intensify channel--hillslope coupling, thereby recruiting logs to the channel, around which new jams can form.
Earth Surf. Dynam., 3, 311-320, doi:10.5194/esurf-3-311-2015, 2015
Bedload transport controls bedrock erosion under sediment-starved conditions
Summary: We applied a spatiotemporally highly resolved dataset of discharge, sediment transport and bedrock erosion data to assess the validity of landscape evolution models at the process scale (resolution of square meters and minutes). The tools effect is found to be the dominant driver of erosion and an easy model is able to predict measured erosion. For larger scales common discharge-dependend modeling with a discharge threshold is adequate to regive the overal trend of the erosion signal.
Earth Surf. Dynam., 3, 291-309, doi:10.5194/esurf-3-291-2015, 2015
Tectonic and climatic controls on the Chuquibamba landslide (western Andes, southern Peru)
Summary: This study deals with the control of crustal tectonic activity and Altiplano climatic fluctuations in the evolution of the arid western Andes. Based on geomorphic analysis coupled with terrestrial cosmogenic nuclide investigation, we point out the role of active faulting and wet events in the development of the Chuquibamba landslide (southern Peru). Our main outcome is that the last major debris flow coincides in time with the Ouki wet climatic event identified on the Altiplano.
Earth Surf. Dynam., 3, 281-289, doi:10.5194/esurf-3-281-2015, 2015
Hitting rock bottom: morphological responses of bedrock-confined streams to a catastrophic flood
Summary: We document the responses of bedrock-confined rivers to an extreme flood which occurred in southeast Queensland, Australia, in 2011. Through a combination of field- and desktop-based analyses we show that widespread removal of coarse-grained mantle occurred, with boulders up to 4m in diameter being locally mobilised. We show that normalised erosion in this extreme event is scaled to basin area and that this large flood has exposed bedrock steps and straths exposing them to ongoing erosion.
Earth Surf. Dynam., 3, 265-279, doi:10.5194/esurf-3-265-2015, 2015
Decadal-scale soil redistribution along hillslopes in the Mojave Desert
Earth Surf. Dynam., 3, 251-264, doi:10.5194/esurf-3-251-2015, 2015