Important Erosion Research Articles

Dentine hypersensitivity.

Dentine hypersensitivity is a common oral pain condition affecting many individuals. The aetiology is multifactorial; however, over recent years the importance of erosion has become more evident. For dentine hypersensitivity to occur, the lesion must first be localised on the tooth surface and then initiated to exposed dentine tubules which are patent to the pulp. The short, sharp pain symptom is thought to be derived from the hydrodynamic pain theory and, although transient, is arresting, affecting quality of life. This episodic pain condition is likely to become a more frequent dental complaint in the future due to the increase in longevity of the dentition and the rise in tooth wear, particularly amongst young adults. Many efficacious treatment regimens are now available, in particular a number of over-the-counter home use products. The basic principles of treatment are altering fluid flow in the dentinal tubules with tubule occlusion or modifying or chemically blocking the pulpal nerve.

Geo‐effectiveness and radial dependence of magnetic cloud erosion by magnetic reconnection

Key PointsMC erosion has a significant impact on geo‐effectivenessCombined importance of erosion and compression on geo‐effectivenessMeasured reconnection rates are consistent with observed erosion

The importance of erosion in distributary channel network growth, Wax Lake Delta, Louisiana, USA

Research Article| January 01, 2014 The importance of erosion in distributary channel network growth, Wax Lake Delta, Louisiana, USA John B. Shaw; John B. Shaw Jackson School of Geosciences, University of Texas at Austin, C9000, Austin, Texas 78712, USA *Current address: Department of Geology and Geophysics, University of Wyoming, Department 3006, Laramie, Wyoming 82071, USA. Search for other works by this author on: GSW Google Scholar David Mohrig David Mohrig Jackson School of Geosciences, University of Texas at Austin, C9000, Austin, Texas 78712, USA Search for other works by this author on: GSW Google Scholar Author and Article Information John B. Shaw *Current address: Department of Geology and Geophysics, University of Wyoming, Department 3006, Laramie, Wyoming 82071, USA. Jackson School of Geosciences, University of Texas at Austin, C9000, Austin, Texas 78712, USA David Mohrig Jackson School of Geosciences, University of Texas at Austin, C9000, Austin, Texas 78712, USA Publisher: Geological Society of America Received: 20 May 2013 Revision Received: 11 Sep 2013 Accepted: 12 Sep 2013 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2013 Geological Society of America Geology (2014) 42 (1): 31–34. https://doi.org/10.1130/G34751.1 Article history Received: 20 May 2013 Revision Received: 11 Sep 2013 Accepted: 12 Sep 2013 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation John B. Shaw, David Mohrig; The importance of erosion in distributary channel network growth, Wax Lake Delta, Louisiana, USA. Geology 2014;; 42 (1): 31–34. doi: https://doi.org/10.1130/G34751.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract A river delta’s shape and kinematics are dictated by the three-dimensional evolution of its distributary channels on the delta front, yet measurements of this evolution are scarce. We supply four bathymetric surveys documenting this evolution for Gadwall Pass—part of the Wax Lake Delta, one of the few rapidly prograding regions of the greater Mississippi Delta in coastal Louisiana, United States. This distributary channel extends 2–6 km beyond the sub-aerially emergent delta (dependent on water surface elevation) and bifurcates into four similarly sized distributary channels (average channel width = ∼150 m) in this sub-aqueous reach. Distributary channel growth proceeds primarily through erosion of the unchannelized foreset deposit, and growth patterns differ between high and low river flow. During high river flow, high upstream sand supply acts to aggrade the bed both inside and outside of the channel network. Erosion during high flow is focused at the sand shoals that define the sidewalls of the bifurcate channels, causing channel network rearrangement into a single primary channel with the remaining secondary channels branching off of it. During low river flow, bed erosion is focused at channel tips and the beds of all of the subaqueous distributary channels, leading to a bayward extension of each channel tip by ≥0.87 channel-widths. Channel-bottom erosion during low river flow is enhanced by tidally modulated currents that support sand suspension and transport in the subaqueous channels during ebb tide while receiving only a small sand supply from upstream. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Efectos de las rodadas de tractores en la escorrentía y erosión de suelos en laderas cultivadas con viñedos

Mechanization characterizes the vineyards of La Rioja, one of the most important wine regions in Spain. Farming operations (plowing, soil removal, herbicide and pesticide application, harvesting of grapes and its transportation, etc.) are carried out with tractors that usually move in the direction of maximum slope, generating wheel tracks approximately 50 cm wide and 5-7 cm deep. The displacement of tractors on plots leads to the compaction of the topsoil and the subsoil. On the other hand, the location of vineyard parcels on steep slopes favours the erosive impact of surface runoff. This paper provides information on the role played by wheel tracks on soil loss by runoff in vineyards. To obtain this information, rainfall simulations with different intensities were carried out. The results confirm that, with moderate and high rainfall intensity, the runoff starts earlier and reach higher values in wheel tracks, due to compaction of the topsoil. Differences between wheel tracks and interrills are less pronounced on sediment yield. These differences are minimal in high intensity storms, having the tractor tracks lesser importance in erosion. By contrast, the drainage micro-network of hillslopes, eliminated by tillage and reactivated by heavy rainfall, seems to have more impact on runoff and erosion. The results obtained with the rainfall simulation experiments shed light on the relationships between runoff, raindrop impact and suspended sediment transport.

Effects of Vetiver (Vetiveria nigritana) on Infiltration Characteristics of Kaolinitic Alfisol of Ibadan, South-Western Nigeria

The importance of erosion in relation to variability of water and soil losses from a parcel of land can be revealed in the measurements of the infiltration characteristics and runoff under a comparable vetiver grass strips and collection tanks within the plots. This experiment is aimed at assessing the variability of runoff and soil loss due to infiltration characteristics of the runoff plots. This study involved three vetiver plots of 20 m interval measured out of six plots (40 m × 3 m each) randomly distributed over a land area of 0.072 ha. The study was conducted on a 6 % slope experimental plot, along Parry Road of the University Ibadan, during the 2007 raining season. The texture of the soil was generally loamy sand. Mean total runoff among the plots was in the trend of no-vetiver plots > vetiver plots (13.50mm > 4.99 mm), the same was true for mean total soil loss (28.78kg/ha > 12.96kg/ha). Variability in the amounts of runoff was moderate in vetiver plots and highly variable in no-vetiver plots (CV = 24 % and 40 % respectively. The correlation between measured soil physical properties and infiltration characteristics with runoff revealed that fine sand content of the soil was negatively related with runoff (r = 0.6450*), but the reverse relationship was true for porosity inferred from soil bulk density and sorptivity of the soil (r = -0.7650*, and -0.8956* respectively).

Introduction to special issue: The future of geomorphology

Geomorphology, and more specifically geography-based geomorphology, has clearly entered some interesting times of late. While this means that there are exciting research opportunities emerging for the geomorphologist interested in multidisciplinary research, questions have also been asked about whether or not such developments necessitate a change in geomorphological education. Two recent papers provide a flavour for some of the relevant issues. In the first, Church (2005) noted that an external driver for a change in the research direction of geomorphology has been the growing awareness of the importance of erosion and sedimentation for understanding tectonic processes (see the papers by Brocklehurst and Dadson in this issue). He also noted that this type of study requires some expertise in numerical computation of the differential equations that describe these processes, but the current ‘geomorphological pedagogy’ (at least in geography departments) is largely descriptive, meaning that students are not being taught the things they need to know in order to engage with such research. This in turn suggests that we need to think about either the nature of the training we provide or where the future geomorphologists are going to come from (Keylock, 2007). In a response to Church, Summerfield (2005) also highlighted the increasing importance of geomorphological research for understanding the earth system at a large scale. However, he focused on the analysis of digital elevation models and the emergence of techniques such as low temperature thermochronology as critical for catalysing this new, large-scale, tectonic geomorphology. Hence, the two papers considered computational or geophysical/geochronological techniques as critical for the emerging emphases in geomorphology but, given the state of geomorphic training within geography, neither author felt confident in asserting that the geography-based geomorphologist could contribute to these emerging agendas directly. Church advocated a role in environmental stewardship, using scientific and social scientific skills to help communicate the science to policy-makers. Summerfield felt that the geography-based geomorphologist would have a role to play in multidisciplinary research teams, using their field experience to study critically some of the underlying assumptions made in the new geomorphology. In both views, therefore, the prognosis for traditional geomorphology (particularly as undertaken by geographers) to engage with these emerging foci is poor unless we reflect carefully on the nature of the research

Coupling of rock uplift and river incision in the Namche Barwa-Gyala Peri massif, Tibet

Geodynamic modeling demonstrates the strong potential for erosion to influence the pattern and style of deformation in active mountain belts, but field studies yield conflicting views on the importance of erosion in influencing orogenesis. Here we compare patterns in river power, inferred excess fluvial-transport capacity, topographic relief, precipitation, and mineral-cooling ages to assess the coupling between surface erosion and rock uplift within the vicinity of the Namche Barwa–Gyala Peri massif, an active antiformal structure within the eastern Himalayan syntaxis. Our rich and dense data set reveals a tight spatial correspondence of fluvial incision potential, high relief, and young cooling ages. The spatial coincidence is most easily explained by a sustained balance between rock uplift and denudation driven by river incision over at least the last ∼1 m.y. The Yarlung Tsangpo–Brahmaputra River is the largest and most powerful river in the Himalaya, and two lines of evidence point to its active role in the dynamic interaction of local erosion, rock uplift, thermal weakening of the lithosphere, and deformation: (1) Whereas along the rest of the Himalayan front, high relief and high rock uplift rates are essentially continuous, the high relief and rapid exhumation in the syntaxis is restricted to a “bull's-eye” pattern exactly where the largest river in the Himalaya, the Yarlung Tsangpo–Brahmaputra, has the most energy per unit area available to erode its channel and transport sediment. (2) The location of rapid incision on the Yarlung Tsangpo–Brahmaputra has been pinned for at least 1 m.y., and without compensatory uplift of the Namche Barwa–Gyala Peri massif during this time the river would have eroded headward rapidly, incising deeply into Tibet.

First results of cosmogenic dated pre-Last Glaciation erratics from the Montoz area, Jura Mountains, Switzerland

The Jura Mountains are a perialpine chain bending from the SW to the NW of Switzerland. Alpine ice reached only marginal areas of this chain during the Last Glacial Maximum (LGM) but remaining erratic boulders of alpine origin indicate older glaciations of unknown age, tentatively correlated either with the classical Rissian or with the Most Extensive Glaciation. Presented here are the first results of dating these pre-LGM boulders by using cosmogenic radionuclides ( 10Be) and noble gases ( 21Ne). Both data sets are in good agreement within 1 σ error, with radionuclide apparent exposure ages ranging from 60 to 107 ka, and noble gas apparent ages from 73 to 123 ka. Considering the importance of erosion on older boulders, the age of the erratics corresponds most probably to Marine Isotope Stage 6. These results are encouraging for further studies on pre-LGM erratic boulders in the mid-latitudes.

Prevalence of dental erosion and the implications for oral health.

The literature on dental erosion is made up of a number of areas, some of which are reviewed here: there are anecdotal case reports, linking a small number of clinical cases with a possible etiological factor. The second area of evidence concentrates on case control studies in which there is a strong association with dental erosion, for example, patients with bulimia. The final piece of epidemiological evidence is beginning to emerge as prevalence studies, but the information from prevalence data worldwide is scanty. It is difficult to compare prevalence studies because of the different indices used in the various studies and also because of the different teeth assessed in the sample. Standardization of indices used would overcome some of these differences as would the reporting of results in a comparable way. However, identifying the true prevalence of erosion per se is fraught with difficulty because there may be more than one etiological factor operating and attrition and or abrasion may complicate the picture, especially in older populations. Case reports frequently associate evidence of erosion with excessive use of particular drinks or foodstuffs so they must be viewed with caution. There is an increasing awareness, amongst the dental profession, of the potential for this particular form of tooth wear to occur. It is important that the dental team is vigilant and instigates preventive measures before tooth tissue loss becomes clinically significant. The importance of erosion in dental health promotion should not be overlooked.

Rates and predictability of ephemeral gully erosion in two contrasting environments

Summary Ephemeral gully erosion in agricultural land is an important source of sediment that is frequently being overlooked and not accounted for in soil erosion studies. However, there is field evidence that ephemeral gully erosion is responsible for significant soil losses. On the other hand, little is known about the factors controlling ephemeral gully erosion. In addition, the relative contribution of ephemeral gully erosion to total sediment production in agricultural catchments has not been assessed. The aim of this study is to assess the relative importance of ephemeral gully erosion in two different environments. In this study we use aerial photographs to estimate the relative importance of ephemeral gully erosion in topographically defined flow paths in the sediment budget of some study catchments. These study catchments are located in Southern Portugal with a dominance of lithosols and Central Belgium where loam and sandy loam soils prevail. The field data indicate that erosion in topographically defined drainage lines is the dominant sediment source and causes the major erosion threat in the loam belt of Belgium and for the stony soils in the Alentejo region of south Portugal ; the ratio between the soil loss due to ephemeral gully erosion and rill- interill erosion ranges between 0.4 and 2.3 for the Belgian study sites and between 4.5 and 5.2 for the Portugese catchments. Therefore, the importance of erosion in drainage lines has to be taken into account when planning erosion control measures at the catchment scale. The observed pattern of ephemeral gully erosion can not be explained by using the available rill erosion equations. However, in the loamy region of Belgium the pattern of ephemeral gully erosion can be predicted by using the product of upslope contributing area (A) and the slope gradient (S) which is a measure for the erosi vity of the concentrated flow. In Portugal however, the pattern of ephemeral gullies can be predicted by a combination of A. S (measure for the erosivity of the overland flow) and a measure of soil saturation (ln(A/S)). The soil profile is not very deep and is overlaying an impermeable rock layer. These results indicate that erosion in topographically defined concentration lines in Belgium is mainly the result of Hortonian overland flow while in Portugal soil saturation and related seepage forces seem to be the dominant incision mechanism.

Processus géomorphologiques, formes du relief et interprétations des paléo-environnements quaternaires (Geomorphologic processes, landforms and interpretations of quaternary paleo-environments)

Abstract. - Better knowledge of geomorphologic processes through laboratory and field experiments and of land forms based on fields studies, allowed a (re)interpretation of quaternary deposits. Type cases from several regions in Belgium with different eolian covers are presented : (1) the dune station at Kalmthout and coversand and dune deposits ; (2) gravel lags in hilly regions ; (3) primary land-forms of late Weichselian age and the nature of loess sedimentation simulated in an aerodynamic wind tunnel, and (4) the importance of erosion under forest and after deforestation.

Forestry in Italy

IN Forestry of June 1934 is an article entitled “The Fascist Government and the Restoration of Italian Forests” by Prof. Aldo Pavari, director of the Royal Experimental Station for Sylviculture, Florence. Prof. Pavari deals with the forest problems in Italy, Italian forestry policy from 1887 to the march on Rome in 1922, Fascist forest legislation, the National Trust militia and instruction and experi mental work in forestry. Of the total area of Italy, 31 million hectares, only a little more than 2J million hectares are unproductive, that is, water, roads, buildings, sterile mountain slopes and crests, etc. Of the remainder, about 53-8 per cent is under agriculture, 26-7 per cent is pasture land of varying quality and 19-5 per cent, or 5J million hectares, is covered by forest. These area totals are of import ance in a mountainous country like Italy, which has vast areas subject to erosion as a result of the geo logical formation, whilst having at the same time an irregularly distributed rainfall. A general survey of soil conditions in Italy shows that, while the plains are intensively cultivated and the hills fertile, with vineyards, olives and other tree crops, the mountains have scarcely any woods and are generally in a low state of productivity. The so-called ‘productive mountain pasture's are often nothing more than coppices, where constant grazing leads to progressive degradation and erosion of the soil, and thus the importance of erosion and floods increases from year to year with tragic consequences for the mountains themselves as well as for the hills below, leading to a constant destruction of the nation's resources and wealth. The measures by which the Duce proposes to improve the existing state of affairs are explained by the following three clauses of the Fascist Forest Legislation: “(a) To secure and defend the stability of the soil and the regularity of the water supply.

III.—Glaciated Valleys in the Cuillins, Skye

Many geologists have recognized that valleys, which have once been occupied by large glaciers, exhibit peculiarities which can only be ascribed to glacial erosion modify in g the earlier water-worn form of the land-surface. Indeed, anyone who allows ice-action to be locally a factor of importance in erosion, must expect that the resulting topographical forms will differ in some measure from those proper to water-erosion. Not only does ice,invirtue of its physical properties, obey different laws as regards pressure and flow, but, what is of equal importance, it fills the whole valley instead of following certain narrow channels. We may hope that, just as Gilbert and others have worked out the principles of watererosion, so the much more difficult problem of ice-erosion may some day be reduced to analysis. An attempt in this direction has been made by McGee in a paper on “Glacial Canons,” which, however, I cite here rather for its brief summary of the observed characteristics of glaciated valleys.