5,478 research outputs found
The application of terrestrial laser scanning to aeolian saltation cloud measurement and its response to changing surface moisture
No full textSaltation is the dominant form of aeolian transport of sand sized grains, yet its heterogeneous spatial and temporal distribution, and inherent feedback and interaction with the surface over which sand is transported, hinders large scale quantification. In this letter we present preliminary data on saltation cloud characteristics quantified using terrestrial laser scanning (TLS). These data, together with surface moisture and surface roughness patterns, elucidate the importance of saltation in the development of protodunes on a drying beach, and indicate the potential usefulness of TLS in examining aeolian processes in both beach and desert environments
Modelling vegetated dune landscapes
No full textThis letter presents a self-organising cellular automaton model capable of simulating the evolution of vegetated dunes with multiple types of plant response in the environment. It can successfully replicate hairpin, or long-walled, parabolic dunes with trailing ridges as well as nebkha dunes with distinctive deposition tails. Quantification of simulated landscapes with eco-geomorphic state variables and subsequent cluster analysis and PCA yields a phase diagram of different types of coastal dunes developing from blow-outs as a function of vegetation vitality. This diagram indicates the potential sensitivity of dormant dune fields to reactivation under declining vegetation vitality, e.g. due to climatic changes. Nebkha simulations with different grid resolutions demonstrate that the interaction between the (abiotic) geomorphic processes and the biological vegetation component (life) introduces a characteristic length scale on the resultant landforms that breaks the typical self-similar scaling of (un-vegetated) bare-sand dunes
Investigating parabolic and nebkha dune formation using a cellular automaton modelling approach
No full textVegetation plays an important role in shaping the morphology of aeolian dune landscapes in coastal and semi-arid environments, where ecogeomorphic interactions are complex and not well quantified. We present a Discrete ECogeomorphic Aeolian Landscape model (DECAL) capable of simulating realistic looking vegetated dune forms, permitting exploration of relationships between ecological and morphological processes at different temporal and spatial scales. The cellular automaton algorithm applies three simple rules that lead to self-organization of complex dune environments, including nebkhas with distinctive deposition tails that form in association with mesquite-type shrubs, and hairpin (long-walled) parabolic dunes with trailing ridges that evolve from blowouts in association with vegetation succession. Changing the conditions of simulations produces differing landscapes that conform qualitatively to observations of real-world dunes. The model mimics the response of the morphology to changes in sediment supply, vegetation distribution, density and growth characteristics, as well as initial disturbances. The introduction of vegetation into the model links spatial and temporal scales, previously dimensionless in bare-sand cellular automata. Grid resolutions coarser than the representative size of the modelled vegetation elements yield similar morphologies, but when cell size is reduced to much smaller dimensions, the resultant landscape evolution is dramatically different. The model furthermore demonstrates that the relative response characteristics of the multiple vegetation types and their mutual feedback with geomorphological processes impart a significant influence on landscape equilibria, suggesting that vegetation induces a characteristic length scale in aeolian environments. This simple vegetated dune model illustrates the power and versatility of a cellular automaton approach for exploring the effects of interactions between ecology and geomorphology in complex earth surface systems
Surface and Meteorological Data at Sand Creek, Great Sand Dunes National Park, Colorado, USA in March and April 2019
No full textWind, sediment transport and surface morphological data collected at Sand Creek during a month long field campaign in March and April 2019 to investigate protodune development under bimodal winds. Data is used in the accepted paper ‘Dune initiation in a bimodal wind regime’, Journal of Geophysical Research: Earth Surface, by Delorme, P., Wiggs, G.F.S., Baddock, M.C., Claudin, P., Nield, J.M. and Valdez, A. (accepted 18th September 2020, article reference number 2020JF005757R; https://repository.lboro.ac.uk/articles/Dune_initiation_in_a_bimodal_wind_regime/12973817) Surface morphological data: This is terrestrial laser scanned (TLS) data collected of the creek sand surface during multiple visits. The data is raw point cloud format in text columns of x, y and z coordinate data. It has been orientation in local format (the origin is located at 13UTM 443152, 4184478). *_full_lowres cover the whole creek surface and the banks on either side. * is the date that the data was collected in yymmdd format. All other data is high resolution section of the actual creek surface within the channel. Each data set uses the same coordinate system. Data can be viewed in any spatial software. Wind and sediment data were collected from a fixed point on the eastern edge of the creek channel. The data is in csv file format with column titles and can be viewed in any text or database software. See Delorme et al. (accepted) for more details.</span
Whose story is it anyway? The ethics of narration and the narration of ethics in Summertime and Die Sneeuslaper
No full textIncludes bibliographical references.This dissertation analyses and compares the narrative strategies in J.M. Coetzee’s Summertime and Marlene van Niekerk’s Die sneeuslaper and considers the implications of these strategies for the authors’ exploration of the ethics of writing. Much has been written about the literary oeuvres of both Coetzee and Van Niekerk, including studies of the translations of Van Niekerk’s Afrikaans novels into English. There are few “interlingual” comparative studies of contemporary works in Afrikaans and English, however, and certainly none to my knowledge which compares the work of Coetzee and Van Niekerk. My contribution to the conversation about Coetzee’s and Van Niekerk’s work, but also to an increasingly multilingual and interconnected South African literary criticism, will be a comparison of one recent work by each of these two authors, written in English and Afrikaans respectively. I draw on the theories of Bakhtin, Barthes and Levinas to consider the ethical dimension of texts in which “double-voicedness”, a questioning not only of existence, but of the self is fore grounded in the content and narrative structure; where there is a shift in focus from the author to the reader (“the birth of the reader”) and “utterances” are made with the response of “the other” in mind
The dynamism of salt crust patterns on playas
No full textPlayas are common in arid environments and can be major sources of mineral dust that can influence global climate. These landforms typically form crusts that limit evaporation and dust emission, modify surface erosivity and erodibility, and can lead to over prediction or under prediction of (1) dust-emission potential and (2) water and heat fluxes in energy balance modeling. Through terrestrial laser scanning measurements of part of the Makgadikgadi Pans of Botswana (a Southern Hemisphere playa that emits significant amounts of dust), we show that over weeks, months, and a year, the shapes of these surfaces change considerably (ridge thrusting of >30 mm/week) and can switch among continuous, ridged, and degraded patterns. Ridged pattern development changes the measured aerodynamic roughness of the surface (as much as 3 mm/week). The dynamic nature of these crusted surfaces must be accounted for in dust entrainment and moisture balance formulae to improve regional and global climate models
"The day of the great writer is gone for ever": Author surrogacy in Martin Amis’s Money and J.M. Coetzee’s Summertime.
No full textThis study focuses on the use of author surrogacy in the novels Money: A Suicide Note by Martin Amis and Summertime: Scenes from Provincial Life by J.M. Coetzee. It addresses the connection between their use of author surrogacy and their comments on what scholars classify as the postmodern cultural condition. Both authors have written themselves into their novels with a different purpose but both used strikingly similar themes to incorporate this purpose, although the stress on these themes varies. Authorial power, the distinction between the real and the imagined, and the fading line between high- and lowbrow culture are examples of the topics discussed in this study with regards to author surrogacy and the postmodern cultural condition. This study concludes that, through their use of author surrogacy, J.M. Coetzee mainly aims to critique, while Martin Amis satirises postmodern culture.
Keywords: Amis, author surrogacy, authorial power, Coetzee, fact-fiction distinction, high- and lowbrow culture, postmodern cultural condition
O doświadczeniu obcości języka w twórczości J.M. Coetzeego. Słowo wstępne
No full textThe present foreword refers to the address delivered by J.M. Coetzee on the occasion of conferring upon him by the University of Silesia the doctor honoris causa degree. Particular attention is paid to his thoughts on the role of English in the world of today. The author of the foreword shows that reflection on language in general and its role in moulding one’s identity in present in the Nobel laureate’s works, including his most recent novels. Further into the foreword, the author briefly discusses text reprinted in Śląskie Studia Polonistyczne: the already mentioned address by J.M. Coetzee, the conversation with the Author, and an article devoted to his works written by Robert Kusek.The present foreword refers to the address delivered by J.M. Coetzee on the occasion of conferring upon him by the University of Silesia the doctor honoris causa degree. Particular attention is paid to his thoughts on the role of English in the world of today. The author of the foreword shows that reflection on language in general and its role in moulding one’s identity in present in the Nobel laureate’s works, including his most recent novels. Further into the foreword, the author briefly discusses text reprinted in Śląskie Studia Polonistyczne: the already mentioned address by J.M. Coetzee, the conversation with the Author, and an article devoted to his works written by Robert Kusek
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