Lichens: Lichenometric dating of diachronous surfaces

This paper describes software to accompany McCarroll, D. 1993. ‘Modelling late-Holocene snow-avalanche activity: incorporating a new approach to lichenometry’, Earth Surface Processes and Landforms 18 , 527–539; and McCarroll, D., Matthews, J. A. and Shakesby, R. A. 1995. ‘Late-Holocene snow-avalanche activity in southern Norway: interpreting lichen-size-frequency distributions using an alternative to simulation modelling’, Earth Surface Processes and Landforms 20 , 465–471.     

World Soil Day and earth surface processes

To celebrate World Soil Day 2014, this editorial summary and Special Issue draws together a number of the most significant contributions that have appeared in Earth Surface Processes and Landforms since 2010. As a group they show the increasing importance of interdisciplinary work in this area of overlap, and point to significant opportunities for future research development, particularly with respect to integrated modelling and interactions with climate change. Copyright © 2014 John Wiley & Sons, Ltd.     

Distance,time and scale in soil erosion processes

This commentary brings together, as a virtual Special Issue, a number of recent papers in Earth Surface Processes and Landforms that are all related to issues of scale in soil erosion. Empirical concepts that were developed in the 1940s are now in need of re‐thinking, and papers are increasingly exploring, through modelling and measurement, appropriate ways to recognize the mechanisms that connect processes across time and space scales. Issues include a more nuanced approach to selective transportation, responses to variability in surface and sub‐surface conditions and the need to analyse measurements in ways that can be transferred between sites and storms. Copyright © 2010 John Wiley & Sons, Ltd.     

Barrier response to sea level rise and storms

This commentary brings together, as a Virtual Special Issue, several recent papers in Earth Surface Processes and Landforms that improve our understanding of coastal barrier response to relative sea level rise and a change in the frequency and/or magnitude of storm events. The ability to predict barrier response depends on the ability to quantify the spatial and temporal scales of sediment exchange amongst the nearshore, beach and dune. This exchange controls the height of the dune, which in turn determines the transfer of sediment to the backbarrier through washover and/or blowouts. The papers in this issue provide new insight on beach–dune interaction and the importance of this interaction to long‐term barrier evolution across a range of sites and scales, and how active management can influence this interaction and alter barrier response. Copyright © 2018 John Wiley & Sons, Ltd.     

Wind direction and complex sediment transport response across a beach–dune system

Evidence from a field study on wind flow and sediment transport across a beach–dune system under onshore and offshore conditions (including oblique approach angles) indicates that sediment transport response on the back‐beach and stoss slope of the foredune can be exceedingly complex. The upper‐air flow – measured by a sonic anemometer at the top of a 3·5 m tower located on the dune crest – is similar to regional wind records obtained from a nearby meteorological station, but quite different from the near‐surface flow field measured locally across the beach–dune profile by sonic anemometers positioned 20 cm above the sand surface. Flow–form interaction at macro and micro scales leads to strong modulation of the near‐surface wind vectors, including wind speed reductions (due to surface roughness drag and adverse pressure effects induced by the dune) and wind speed increases (due to flow compression toward the top of the dune) as well as pronounced topographic steering during oblique wind approach angles. A conceptual model is proposed, building on the ideas of Sweet and Kocurek (Sedimentology 37 : 1023–1038, 1990), Walker and Nickling (Earth Surface Processes and Landforms 28 : 111–1124, 2002), and Lynch et al. (Earth Surface Processes and Landforms 33 : 991–1005, 2008, Geomorphology 105 : 139–146, 2010), which shows how near‐surface wind vectors are altered for four regional wind conditions: (a) onshore, detached; (b) onshore‐oblique, attached and deflected; (c) offshore, detached; and (d) offshore‐oblique, attached and deflected. High‐frequency measurements of sediment transport intensity during these different events demonstrate that predictions of sediment flux using standard equations driven by regional wind statistics would by unreliable and misleading. It is recommended that field studies routinely implement experimental designs that treat the near‐surface wind field as comprising true vector quantities (with speed and direction) in order that a more robust linkage between the regional (upper air) wind field and the sediment transport response across the beach–dune profile be established. Copyright © 2012 John Wiley & Sons, Ltd.     

Reappraising the geomorphology‐ecology link

This thematic Virtual Special Issue highlights a personal selection of 18 recent (2007–2009) contributions to Earth Surface Processes and Landforms. These papers provide a flavour of recent research that is concerned with furthering our understanding of the many ways in which the biosphere interacts with the physical and chemical processes of sediment transfer/transformation. Much of this research has focused on understanding the mechanics by which the biota can modulate sediment transport and the strength of earth surface materials, often with the aim of applying that knowledge to enhance bioremediation methods of erosion control. This work continues to be fundamentally important in enhancing our understanding of earth surface processes, but often treats the biosphere and physical world as uncoupled entities. This selection therefore also provides samples of work that point to an ongoing but significant disciplinary reappraisal in which it is the interactions between ecological and geomorphological realms that are of primary interest. Copyright © 2009 John Wiley & Sons, Ltd.     

Linking landslides,hillslope erosion,and landscape evolution

This Virtual Issue highlights 10 recent innovative, unconventional, or otherwise significant contributions to Earth Surface Processes and Landforms that help advance the state‐of‐the‐art in research on linkages between landslides, hillslope erosion, and landscape evolution. The selected studies address this feedback within a temporal spectrum that ranges from the event to the millennial scale, thus underscoring the importance of detailed field observations, high‐resolution digital topographic data, and geochronological methods for increasing our capability of quantifying landslide processes and hillslope erosion. Copyright © 2009 John Wiley & Sons, Ltd.     

New developments in process understanding and modelling in geomorphology: introduction and overview

This Special Issue of Earth Surface Processes and Landforms develops from the ‘Geomorphology: a 2020 Vision’ Annual Conference of the British Society for Geomorphology, organised at the University of Birmingham, UK, in July 2007. Entitled ‘New Developments in Process Understanding and Modelling in Geomorphology’, the Issue comprises a vibrant selection of 10 ‘process’ papers from leading researchers in geomorphological processes who presented at Birmingham. It aims to provide a readily accessible source of new and emerging ideas in understanding different landform processes across a range of space and time scales, based on innovations in geomorphological modelling and monitoring. The last few years have seen significant and exciting changes in geomorphology, especially in conceptual developments, numerical simulations, monitoring methodologies, data‐acquisition strategies and dating techniques. The resultant empirical datasets, theory development and modelling results have generated substantial advances in the understanding of geomorphological processes, form‐process feedbacks, scale impacts, long‐term landform evolution, the effects of climate and environmental change, and human impacts and management strategies. The Special Issue attempts to address the following key challenges: (a) to build on our Conference theme ‘Geomorphology: a 2020 Vision’, by identifying fundamental areas where doors need to be opened, for example in theory development, conceptual understanding, model evaluation, integration of the chemistry, physics, biology and mathematics of geomorphological processes, experimental validation, data needs and monitoring requirements; (b) to look forward to the next decade and beyond, and critically examine some of the approaches we will need for the questions ahead; and (c) to stimulate new research in the geomorphological sciences by highlighting both research gaps and promising developments, including emerging process modelling approaches, monitoring technologies and robust datasets. Copyright © 2010 John Wiley & Sons, Ltd.     

DISCUSSION: APPLICATION OF THE QDa–Md METHOD OF ENVIRONMENTAL DISCRIMINATION TO PARTICLE SIZE ANALYSIS OF FINE SEDIMENTS

Duck's recent finding (R. W. Duck, Earth Surface Processes and Landforms, 1994, 19 , 525–529) that QDa and Md parameters derived from pipette and SediGraph analysis of sediments from Loch Tummel returned similar results can be interpreted in two ways. The observed consistency could result from (i) a general agreement between the methods (as is suggested by Duck) or (ii) from the use of inappropriate parameters (Md and QDa) to describe polymodal distributions.     

Planetary dune analogues: a special issue on integrating models,remote sensing and field data

This article reports on the Special Issue of Earth Surface Processes and Landforms dedicated to planetary dune analogues and the advances that have been made through the integration of remote sensing and terrestrial field data to better model and understand aeolian systems. The 11 articles presented demonstrate a spectrum of analytical techniques that are employed to investigate ripples, dunes, draa and ergs across a variety of spatial and temporal scales. Nine of the papers involve innovative research about aeolian bedforms and processes, while the final two papers are examples of how vast quantities of data may be organized and scrutinized using a GIScience approach. Based on these 11 papers and the many abstracts archived in a series of three planetary dunes workshops at the Lunar Planetary Institute ( http://www.lpi.usra.edu/publications/abstracts.shtml ; LPI Contributions 1403, 1552, and 1673) it is evident that there exists diverse and complementary approaches to the comparative study of landforms and processes for terrestrial and extra‐terrestrial aeolian landscapes that is driven by a vibrant international community of scientists and educators that engage in the cross‐fertilization of ideas. Copyright © 2014 John Wiley & Sons, Ltd.     

REPLY: PEAT MOUNDS WITH NON-UNIFORM PROPERTIES

In estimating the form of a peat mound from the equilibrium water table position, the assumption that hydraulic conductivity shows an exponential decline with depth (as used in the Armstrong (Earth Surface Processes and Landforms, 1995, 20 , 473–477) analysis) may be questioned in some circumstances. However, this does not invalidate the use of the hydrologic model for peat mounds, and results are presented which could be used to evaluate other forms of the depth-dependent relationship.     

Time-averaged flow structure in the central region of a stream confluence: a discussion

This paper is a discussion of Rhoads and Kenworthy (1998) ‘Time-averaged flow structure in the central region of a stream confluence’ Earth Surface Processes and Landforms, 23 , 171–191, that focuses upon the methods used to identify secondary circulation in river channel confluences. It argues that the Rozovskii method that Rhoads and Kenworthy use to rotate their field data to allow identification of secondary circulation cells is flawed, and can result in misleading conclusions about the nature of flow processes in confluences. It recommends that there is a re-emphasis upon helical as opposed to secondary circulation, and that recent developments in both field monitoring and numerical modelling may help significantly in this respect. Copyright © 1999 John Wiley & Sons, Ltd.     

Sediment transport mechanics

The Editor of Acta Geophysica and the Guest Editors wish to dedicate this Topical Issue on Sediment Transport Mechanics to the memory of Stephen Coleman, who died recently. During his career, Stephen had made an outstanding scientific contribution to the topic of Sediment Transport. The level of his contribution is demonstrated in the paper by Aberle, Coleman, and Nikora included in this issue, on which he started working before becoming aware of the illness that led to his untimely death. For scholars and colleagues Stephen remains an example of intellectual honesty and scientific insight.     

REPLY: APPLICATION OF THE QDa–Md METHOD OF ENVIRONMENTAL DISCRIMINATION TO PARTICLE SIZE ANALYSES OF FINE SEDIMENTS BY PIPETTE AND SEDIGRAPH METHODS

Although it may be inappropriate to apply the QDa–Md method to grain-size distribution data of bimodal and polymodal sediments, the aim of the study (R. W. Duck, Earth Surface Processes and Landforms, 1994, 19 , 525–529) was not to defend this methodology. It was to determine whether or not the modern SediGraph yielded particle size data, for a suite of fine-grained, ‘quiet water’ sediments, which are accommodated by the appropriate QDa–Md trend envelopes, originally established on the basis of the pipette method. That this was shown to be the case, despite the considerable differences in the values of QDa and Md recorded in comparative analyses, demonstrates the applicability of the method to SediGraph-derived data for fine-grained sediments and in no way invalidates the approach adopted.     

Special Issue: Gravel Bed Rivers 8

Theoretical, modeling, experimental and monitoring of sediment transport in gravel bed rivers are introduced. The key findings of 27 papers on this theme were published in Earth Surface Processes and Landforms during the past year. Among these, 18 papers were published by attendants of the 8th Gravel Bed River Workshop held in Japan in 2015. This Commentary introduces the main themes associated with these papers including innovations in sediment transport conceptualization and modeling and monitoring, and also three wider themes: the importance of sediment supply; relationships between gravel bed river science and restoration; and the growing recognition of the critical role played by wood in gravel bed rivers. Copyright © 2018 John Wiley & Sons, Ltd.     

Plants as river system engineers: further comments

This paper is a response to commentary on the review by Gurnell (Plants as river system engineers. Earth Surface Processes and Landforms 39 : 4–25, 2014). It covers three themes. First, it explains how the review focused on physical ecosystem engineering by plants, particularly in the northern humid temperate zone. Second, it explains how the review was structured to address that theme and why annual species were not highlighted. Within the humid temperate zone, mature plants of annual species are not present during the seasons of the year when fluvial processes are most active: they survive as seeds or young seedlings, and so their ability to act as river ecosystem engineers is limited. Third, some comments are made regarding the annual species, Himalayan balsam (Impatiens glandulifera), including the traits that enable it to be successful in riparian environments, its competitive ability, its potential role in influencing fluvial sediment dynamics, and the need for controlled experiments to characterize and quantify the latter over one or more complete years. Copyright © 2014 John Wiley & Sons, Ltd.     

Species selection and assessment of eco-engineering effects of seedlings for biogeomorphological landscape experiments

Landscape experiments of fluvial environments such as rivers and deltas are often conducted with live seedlings to investigate effects of biogeomorphological interactions on morphology and stratigraphy. However, such experiments have been limited to a single species, usually alfalfa (Medicago sativa), whereas important environments in nature have many different vegetation types and eco-engineering effects. Landscape experimentation would therefore benefit from a larger choice of tested plant species. For the purpose of experimental design our objective was to identify fast-germinating and fast-growing species and determine their sensitivity to flow conditions during and after settling, their maximum growth, hydraulic resistance and added bank strength. We tested germination time and seedling growth rate of 18 candidate species with readily available seeds that are fast growing and occur at waterlines, plus Medicago sativa as a control. We selected five species that germinate and develop within days and measured properties and eco-engineering effects depending on plant age and density, targeting typical experimental conditions of 0–0.3 m/s flow velocity and 0–30 mm water depth. Tested eco-engineering effects include bank strength and flow resistance. We found that Rumex hydrolapathum can represent riparian trees. The much smaller Veronica beccabunga and Lotus pedunculatus can represent grass and saltmarsh species as they grow in dense patches with high flow resistance but are readily erodible. Sorghum bicolor grows into tall, straight shoots, which add significantly to bank strength, but adds little flow resistance and may represent sparse hardwood trees. Medicago sativa also grows densely under water, suggesting a use for mangroves and perhaps peat. In stronger and deeper flows the application of all species changes accordingly. These species can now be used in a range of landscape experiments to investigate combined effects on living landscape patterns and possible facilitation between species. The testing and treatment methodology can be applied to new species and other laboratory conditions. © 2019 The Authors. Earth Surface Processes and Landforms Published by John Wiley & Sons Ltd. © 2019 The Authors Earth Surface Processes and Landforms Published by John Wiley & Sons Ltd © 2019 The Authors Earth Surface Processes and Landforms Published by John Wiley & Sons Ltd.     

A template for calculating rock surface roughness

This software (which accompanies McCarroll and Nesje, 1996, Earth Surface Processes and Landforms Vol. 21, 963–977) is designed to quantify the roughness of rock surfaces from profiles recorded using either a micro-roughness meter or a simple profile gauge. The roughness index used is the standard deviation of the differences between adjacent height values recorded at set horizontal intervals. Profiles are assumed to be 19 cm long with heights recorded every 5 mm. The template provided assumes that four profiles are recorded from each of ten surfaces (e.g. boulders). Roughness values are calculated using (overlapping) measurement intervals of 5 mm, 10 mm, 15 mm, 20 mm, 25 mm and 30 mm. The results are tabulated and presented as ‘deviograms’ which display both the magnitude and scale of roughness. The spreadsheet used was Quattro-pro for Windows, version 1.00. © 1997 John Wiley & Sons, Ltd.