Total Erosion Research Articles

Quantifying and modelling the impact of land consolidation and field borders on soil redistribution in agricultural landscapes (1954–2009)

Soil erosion rates in cultivated areas have intensified during the last decades leading to both on and off-site problems for farmers and rural communities. Furthermore, soil redistribution processes play an important role in sediment and carbon storage within, and exports from, cultivated catchments. This study focuses on the impact of land consolidation and changes in landscape structure on medium term soil erosion and landscape morphology within a 3.7-ha field in France. The area was consolidated in 1967 and we used the Cs-137-technique to quantify soil erosion for the period (1954-2009). We measured the Cs-137 inventories of 68 soil cores sampled along transects covering the entire area and especially specific linear landforms located along both present and past field borders (i.e., lynchets and undulations landforms, respectively). These results were then confronted with the outputs of a spatially-distributed Cs-137 conversion model that simulates and discriminates soil redistribution induced by water and tillage erosion processes. Our results showed that tillage processes dominated the soil redistribution in our study area for the last 55 years and generated about 95% (i.e., 4.50 Mg.ha(-1).yr(-1)) of the total gross erosion in the field. Furthermore, we demonstrated that soil redistribution was largely affected by the presence of current and also former field borders, where hotspots areas of erosion and deposition (>20 Mg.ha(-1).yr(-1)) were concentrated. Land consolidation contributed to the acceleration of soil erosion through the conversion of depositional areas into sediment generating areas. Although the conversion model was able to reproduce the general tendencies observed in the patterns of Cs-137 inventories, the model performance was relatively poor with a r(2) of 0.20. Discrepancies were identified and associated with sampling points located along the current field borders. Our data suggests that tillage erosion processes near field boundaries cannot be described as a typical diffusive process. These processes near field boundaries should be characterised and taken into account in a future version of the model to accurately simulate rates and patterns of past soil redistribution in fragmented cultivated hillslopes. We also showed that the use of an accurate DEM resulting from LIDAR data, based on present-day topography, leads to the underestimation of soil redistribution rates by the model, especially in this landscape submitted to recent and important morphological changes. Our results have important implications for the simulation of tillage erosion processes and our understanding of soil redistribution processes in complex cultivated areas. This is of particular interest to improve our knowledge and prediction of patterns of soil physical parameters, such as carbon storage or water content, particularly sensitive to surface erosion and landscape structuration. Anglais

Cenozoic erosion and flexural isostasy of Scandinavia

The presence of Cenozoic deposits along the Norwegian Atlantic margin required extensive erosion of the Scandinavian Mountains in a generally cooling climate from the Oligocene to the present. The volume of the deposits implies that the transfer of mass from the inland area to the offshore shelf induced isostatic displacements on a kilometer scale. However, except for glacial excavation of the deep fjords, little is known about the distribution of Cenozoic inland erosion. A long-lasting paradigm incorporates remnants of peneplains at high elevation and assumes very little Cenozoic erosion on these surfaces through time. This scenario has recently been challenged by quantitative geomorphological studies indicating that the matrix of Cenozoic sediments deposited offshore must have been sourced from these surfaces. An alternative explanation for the present-day high-elevation low-relief surfaces is therefore that they evolved throughout the Cenozoic because of glacial and periglacial erosion processes that are known to vary strongly with altitude. Here we explore the implications of the latter scenario by reconstructing a pre-Cenozoic fluvial landscape without elevated low-relief surfaces. We use the present-day offshore sediment volumes for constraining the total Cenozoic erosion, and we find that a likely pre-Cenozoic fluvial landscape is only in few places more than 1km higher than today. The rock mass of the offshore sediments is generally used for filling the fjords created during the Quaternary glaciations and for restoring concave river profiles from sea level to the peaks. Our reconstruction is based on a fluvial landscape algorithm and considers the isostatic response to the transfer of rock mass – from the basins onto the onshore area. A comparison between the reconstructed and the present-day topography demonstrates that offshore tilting of pre-Cenozoic strata can be partly explained by flexural isostatic compensation in response to the Cenozoic erosion and deposition. Locations of future thermochronometry studies for testing Scandinavian landscape evolution models are suggested based on temperature estimates of the present-day surface buried beneath the erosion products restored from the offshore basins.

AB1284 Validity of a computer-assisted manual segmentation software to quantify erosion volume on wrist using computed tomography scans in rheumatoid arthritis

ObjectivesTo investigate the performance of radiography for the detection of wrist bone erosions in rheumatoid arthritis (RA) using multidetector computed tomography (CT) as the reference method, and to assess the...

SAT0088 First year rapid radiological progression is the best predictor of further progression in early arthritis: Results of the ESPOIR cohort

BackgroundOne of the major goal in the treatment of early arthritis is to prevent articular destruction. Several factors predicting joint destruction have been identified but the rapidity of progression during...

FRI0082 Radiographic progression in rheumatoid arthritis in the 21st century

BackgroundProgression of joint damage as measured radiographically is a hallmark of rheumatoid arthritis (RA), and its reduction a key claim for traditional and novel antirheumatic drugs. Data from clinical trials...

THU0314 Plasma IL-6 Levels Correlate with Ultrasound Measures of Disease Activity in Lupus Arthritis

BackgroundThe role of specific cytokines in lupus arthritis has not been elucidated1. This is in stark contrast to rheumatoid arthritis (RA) where an abundance of research has culminated in an...

THU0315 Rhupus’ Arthritis - An MRI and Ultrasound Perspective

BackgroundThe limited application of Ultrasound(US) and MRI to date in SLE is revealing a higher percentage of erosive disease than previous estimates1. Such erosive arthropathy in lupus when associated with...

Resultados preliminares de las pérdidas de suelo en zona agrícola del Penedés (Cataluña, España)

This concerns the evaluation of soil loss through runoff erosion in the agricultura! zones. The area of ·study is situated in the tectonic trench of Penedes (Province of Barcelona), basically made up of neoge and quaternary materials. The quantification of the erosive processes is carried out on experimental plots intalled on prívate estates. It is based on the data obtained from two fundamental variables: climate and runoff. For this purpose we have set up a series of typical meteorological instruments and gathering devices to collect both solid and liquid discharge brought down by the overland flow. These are similar to Gerlach troughs but on a larger scale. During 1983 the soil losses in this experimental zone were 2.4 kg/m2 . The erosion took place atan uneven rate. From a total of 46 rainy days only 11 produced results and 3 of these were responsible for 92% of the total erosion.

Kajian Konservasi Tanah Kritis Berdasarkan Satuan Lahan di Daerah Tangkapan Air Sempor Kabupaten Kebumen

Title : Study of Critical Soil Conservation Based on Land Unit on Sempor’s Catchment Area, Kebumen Regency. This research aims to predict critical soil and soil erosion level of Sempor’s Catchment Area and to recommend the management according to soil conservation. This is an explorative descriptive research based on environment data. The data are obtained from field observation and result of laboratory analysis of soil samples taken from field survey. Furthermore, the data are classified based on critical soil classification to get critical soil map. The data also are calculated based on USLE to get soil erosion prediction. The results of soil erosion prediction are grouped based on erosion hazard levels and result of soil erosion mapping. After knowing critical soil and soil erosion level in each land unit, recommendation is made to manage land according to soil conservation. The result shows that on observation area with total extent 4,333.68 ha there are critical soil about 1,373.68 ha (31.70 %), semi critical about 2,164.54 ha (49.95 %), potentially critical about 440.46 ha (10.16 %) and the others are about 355.00 ha (8.19 %) in the form of settlement and reservoir located at the outside of the observation area. The soil erosion predicted on observation area are divided into 6 classes, those are very low erosion class at about 103.90 ha (2.40 %), low erosion class at about 332.00 ha (7.66 %), moderate erosion class at about 953.78 ha (22.01 %), high erosion class at about 247.53 ha (5.71 %), very high erosion class at about 2,108.50 ha (48.65 %), acute erosion class at about 232.96 ha (5.38 %) and the others are out of observation area. Topography and land management are factors that have the most dominant influence to soil erosion prediction. Total soil erosion on observation area is about 320,958.016 tons/ha or soil erosion average about 74.061 tons/ha/year. The recommendation is to restore critical and erosion through some actions such as reboization or planting with annual crop, vegetation nursery, adding organic matter via organic fertilizer or organic mulches, making and maintaining of terrace and ditches, and agroforestry. Keywords: critical soil, erosion, Sempor, soil coservation

Changes in Agricultural Land Use Affecting Future Soil Redistribution Patterns: A Case Study in Southern Tuscany (Italy)

AbstractLand‐use changes (LUCs) can be defined as the result of the direct action of the stakeholders in a particular area and natural or human driving forces. LUCs can influence various processes within the landscape and can have an impact on landscape functions. An analysis of the impact of LUCs on landscape processes can help to focus future rural policies. LUCs in Mediterranean areas particularly affect landscape functions because of their agro‐pedoclimatical characteristics. The aims of this work are as follows: (i) to characterise LUCs in the last 11 years in a typical Mediterranean area, the Trasubbie river basin (southern Tuscany, Italy); (ii) to extrapolate these changes and create spatially explicit LUC scenarios for the near future; and (iii) to simulate how and where the predicted LUCs may affect soil redistribution. We carried out an analysis of LUCs within the study area and used the trends to propose alternative scenarios for 2013. For these years, we spatially allocated land use (using the Conversions of Land Use and its Effects model) and used a landscape process model (landscape process modelling at multi‐dimensions and scales) to assess soil redistribution patterns. Land use in the study area changed almost linearly between 1996 and 2007, with cereals and annual fodder crops decreasing, and vineyards, perennial pastures and land abandonment increasing. Our LUC scenario extrapolates these dynamics to make predictions for 2013. A comparison of LAPSUS results between LUC and baseline scenarios for 2013 showed an increase in terms of net soil loss and total erosion, and a decrease in terms of sediment delivery ratio. Copyright © 2013 John Wiley & Sons, Ltd.

Soil Erosion Assessment in the Watershed of Dehua District of Fujian Province

Based on different land use types and diverse watersheds of Dehua district of Fujian Province, soil erosion is assessed by using Universal Soil Loss Equation (USLE). According to the results, erosion of Dehua is generally mild, among which total erosion is 952.71×103 t/a and erosion area is 2210.67 km2. It is significant that the vast forest and grassland contribute to avoiding erosion effectively. In addition, the overlap area of Min and Jin River and Chanxi of Min River, the most frequent place of human activities, are the two highest soil erosion watersheds. The result shows that human activities have great influence on soil erosion. This article intends to provide evidence for planning and control measures of soil erosion.

Soil redistribution and organic carbon accumulation under long‐term (29 years) upslope tillage systems

AbstractFew studies have demonstrated soil redistribution under upslope tillage (UT) rather than downslope tillage (DT) and its impact on soil organic carbon (SOC) redistribution in long‐term agricultural practices in hillslope landscapes. We selected two neighbouring sites from the Sichuan Basin, China, one under DT and the other under UT, to determine the pattern of soil and SOC redistribution under a long‐term UT practice. DT caused soil loss at upper slope positions and soil accumulation at lower slope positions. However, UT resulted in soil accumulation at upper slope positions and soil loss at lower slope positions. The total erosion rate decreased by 60.5% after 29 years of UT compared with DT. Having the same direction of soil movement by tillage and water exaggerated total soil loss, whereas having the two movements in the contrasting direction of soil for the two reduced it. SOC stocks at positions from summit to downslope were much larger (33.8%) and at toe‐slope positions were only slightly greater (4.5%) in the UT soils than comparable values for the DT site. The accumulation rate of SOC at the UT site increased by 0.26 Mg/ha/year compared with that at the DT site. It is suggested that soil movement by water and tillage erosion occurred in the same direction accelerates the depletion of SOC pools, whereas the opposite direction of soil movement for the two can increase SOC accumulation. Our results suggest that UT has significant impacts on soil redistribution processes and SOC accumulation on steeply sloping land.

The sediment delivery ratio in a small catchment in the black soil region of Northeast China

The black soil region of northeast China, which covers the Provinces of Heilongjiang, Jilin and the Inner Mongolia autonomous region with black soil, chernozem and meadow soil, has experienced soil erosion since intense agricultural reclamation began approximately 100 years ago. However, the sediment delivery ratio, defined as the fraction of gross erosion that is transported from a given area in a given time interval, is still unclear. In this study, we calculated the delivery ratio and analysed changes in erosive processes within Hebei catchment from 1977 to 2007 based on an analysis of sediments of the Liudui reservoir. The original vegetation layer clearly identified the bottom of the reservoir when it was constructed in 1977; thus, the reservoir sediments could be precisely dated. The delivery ratio, calculated by comparing the sediment deposition in the reservoir with the total soil erosion in the upstream catchment, was found to be exponentially correlated (r2 = 0.95, P < 0.01) with decreasing grain size, except for the fraction <0.002 mm. The delivery ratio for the clays (<0.002 mm) was low, averaging 0.10 during the study period, which indicated partial removal of clays from the reservoir. The changes in the reservoir deposition rate reflected the temporal changes in the erosion processes. The exceptionally high rainfall in 1998 was confirmed by the distributions of 137Cs, 210Pb, and the grain-size of the sediments. Beginning from the position of the original grass layer, we defined three periods from 1977 to 2007 based on deposition rates: 2.40 cm year−1 from 1977 to 1997, 5.60 cm year−1 in 1998 due to unusually high rainfall, and 1.55 cm year−1 from 1999 to 2007. The overall average deposition rate for the entire period was 2.26 cm year−1. Precipitation was found to be the main factor affecting the soil erosion of the study area.

Ecosystem service value losses from coastal erosion in Europe: historical trends and future projections

Coastal zones experience increased rates of coastal erosion, due to rising sea levels, increased storm surge frequencies, reduced sediment delivery and anthropogenic transformations. Yet, coastal zones host ecosystems that provide associated services which, therefore, may be lost due to coastal erosion. In this paper we assess to what extent past and future coastal erosion patterns lead to losses in land cover types and associated ecosystem service values. Hence, historical (based on CORINE land cover information) and projected (based on Dynamic and Interactive Vulnerability Assessment - DIVA - simulations) coastal erosion patterns are used in combination with a benefits transfer approach. DIVA projections are based on regionalized IPCC scenarios. Relative to the period 1975–2050, a case study is provided for selected European coastal country member states. For historical (1975–2006) coastal erosion trends, we observe territory losses in coastal agricultural, water body and forest & semi-natural areas – total coastal erosion equaling over 4,500 km2. Corresponding coastal ecosystem service values decrease from about €22.3 billion per year in 1975 to about €21.6 billion per year in 2006. For future (2006–2050) coastal erosion projections, total territory losses equal between ~3,700 km2 and ~5,800 km2 – coastal wetland areas being affected most severely. Corresponding coastal ecosystem service values decrease to between €20.1 and €19.4 billion per year by 2050. Hence, we argue that the response strategy of EU member states to deal with coastal erosion and climate change impacts should be based on the economic as well as the ecological importance of their coastal zones.

Erosion at the inner wall of JET during the discharge campaigns 2001–2009

The erosion of Be, C, Ni and W marker layers was investigated with long-term samples exposed during the discharge periods 2001-2004 and 2005-2009. The markers were mounted in carbon wall tiles between the inner wall guard limiters (IWGLs) and at positions between the lower end of the IWGLs and the inner divertor entrance. They were analyzed using ion beam analysis techniques before and after exposure. All samples showed strong erosion of all elements. The erosion is predominantly due to neutral particles created by charge-exchange (CX) collisions. The erosion of carbon was about 8×10 19 atoms/cm 2 (about 8 µm) during the 2005-2009 campaign, which gives a total erosion of carbon from the recessed areas between the IWGLs of about 230 g: The inner wall is therefore an important net carbon source. The erosion of the four different elements allows a rough reconstruction of the energy spectrum of the eroding CX neutrals.

Factors Affecting Herbaceous Richness and Biomass Accumulation Patterns of Reclaimed Coal Mines

AbstractOpen‐cast mining reclamation strategies are focused on the identification of the environmental factors at different scales that facilitate the vegetation establishment and development. Here, we characterised the environmental factors at macro‐scale and micro‐scale that influenced the herbaceous richness and biomass accumulation patterns trough a 32‐year chronosequence. Herbaceous richness and biomass were influenced at macro‐scale by successional and soil development gradients whereas at micro‐scale by shrub cover and coarseness gradients. Indeed, certain environmental factors at macro‐scale and micro‐scale contributed simultaneously to determine these gradients. Explicitly, the successional gradient was related to carbon and nitrogen ratio, grazing intensity and Shannon diversity. Across this successional gradient, total herb biomass and Fabaceae biomass were reduced as well as main taxonomical groups richness. Soil development gradient was related to total nitrogen, pH and erosion severity. This gradient only influenced species richness and produced a richness reduction when pH and erosion severity increased. At micro‐scale, the shrub cover gradient was related to organic matter thickness, producing a Poaceae biomass and bryophytes cover increase when shrub cover and organic matter increased. The coarseness gradient was related to the cover of rocks and bare soil, producing a reduction of herb biomass and richness when rocks and bare soil increased. These results emphasise the need to incorporate in the management plans the influence of soil development, successional, shrub cover and coarseness gradients over herbaceous richness and biomass to improve mine reclamation strategies. Copyright © 2013 John Wiley &amp; Sons, Ltd.

Arcing and its role in PFC erosion and dust production in DIII-D

Abstract Two types of arc tracks are observed on the plasma-facing components (PFCs) in DIII-D. “Unmagnetized” random walk tracks are produced during glow discharges; they are rare and have no importance for PFC erosion but may degrade diagnostic mirrors. “Magnetized” scratch-like type II tracks are produced by unipolar arcs during plasma operations; they are formed by “retrograde BxJ” motion of the cathode spot and are roughly perpendicular to the local magnetic field. Type II arcs cause measurable erosion of graphite, but based on the evidence available they are relatively small contributors to the total erosion of carbon in DIII-D compared to other mechanisms such as physical and chemical sputtering and ablation from leading edges. Erosion by arcing of tungsten films deposited on graphite samples was observed in Divertor Material Evaluation System (DiMES) experiments. New DiMES experiments aimed at time-resolved arc measurements are proposed.

Spatial Application of WEPS for Estimating Wind Erosion in the Pacific Northwest

<abstract> <bold><sc>Abstract.</sc></bold> The Wind Erosion Prediction System (WEPS) is used to simulate soil erosion by wind on cropland and was originally designed to run simulations on a field scale. This study extended WEPS to run on multiple fields (grid cells) independently to cover a large region and conducted an initial investigation to assess how well WEPS performed in that environment by comparing simulations for two historical dust events with field observations and satellite images in the Columbia Plateau region of Washington. We modified the WEPS source code to allow it not only to run on multiple grid cells but also to save the state of the simulation so that it can be re-initiated from that state in future runs, allowing the model to be started and then stepped through time incrementally under various future climate or forecast weather scenarios. We initially ran WEPS on the entire state of Washington, with the entire Pacific Northwest region as our ultimate target area, to provide PM₁₀ and eventually PM_2.5 emissions from wind erosion events as input to the chemical transport model CMAQ, which is used by the AIRPACT regional air quality modeling system for the Pacific Northwest. Three principal inputs to WEPS are meteorological data, soil data, and crop management practices. These data, at a 1 km × 1 km grid cell resolution, are the basic input data for running the spatially distributed model. The climatic data from a three-year period were stochastically generated based on statistical representations of past meteorological measurements from stations in the region and were used for initializing WEPS, and then a three-day set of meteorological data corresponding with historical dust storm events were selected for simulation by WEPS of wind erosion of cropland in the state of Washington. The crop management data were selected based on the land use and USDA Natural Resources Conservation Service (NRCS) crop management zones, and the soil data were derived from the NRCS SSURGO database. We aggregated the outputs from 1 km × 1 km grid cells into 12 km × 12 km grid cells for easier visualization and then mapped the total surface soil erosion, suspension, and PM₁₀ emissions for each 12 km × 12 km grid cell. This study shows that WEPS can be successfully extended to run from one field grid cell to multiple field grid cells, and the model can identify regions with high potential for soil erosion by wind. It also demonstrates that WEPS can be used for real-time monitoring of soil erosion and air quality in a large region if actual and forecast weather inputs are available.

Reservoir sedimentation and transformation of morphology in the lower yellow river during 10 year's initial operation of the Xiaolangdi reservoir

The Xiaolangdi Hydro-Project is one of the large projects on the main stem of the Middle Yellow River. It has been operated for more than 10 years, since its impoundment in October, 1999. The reservoir has trapped 2.833×109 m3 of sediment, and caused the total erosion of 1.891×109 t in the Lower Yellow River from October, 1999 through October, 2010. Not only the serious atrophied situation of the Lower Yellow River (LYR) has been resuscitating, but also many new phenomena of sediment transport and behaviors of channel re-establishing are coming into being. They are illustrated and discussed in detail in this paper.

Simulated soil erosion from a semiarid typical steppe watershed using an integrated aeolian and fluvial prediction model

Total soil erosion is a result of both aeolian and fluvial processes, which is particularly true in semiarid regions. However, although physically interrelated, these two processes have conventionally been studied and modelled independently. Recently, a few researchers highlighted the importance and need of considering both processes in concert as well as their interactions, but they did not give specific modelling approaches or algorithms. The objectives of this study were to (1) formulate an integrated aeolian and fluvial prediction (IAFP) model, (2) parameterize the IAFP model for a semiarid steppe watershed located in northeastern China by using literature and historical data and (3) use the model to predict soil erosion in the watershed and assess the sensitivity of predicted erosion to environmental factors such as soil moisture and vegetation coverage. The results indicated that the IAFP model can capture the dynamic interactions between aeolian and fluvial erosion processes. For the study watershed, the model predicted a higher occurrence frequency of fluvial erosion than that of aeolian erosion and showed that these two processes almost equivalently contributed to the average total erosion of 0.07 mm year−1 across the simulation period. The ‘existing’ vegetation cover can provide an overall good protection of the soils, although the vegetation cover was predicted to play a larger role in a drier than a wetter year as well as in controlling aeolian than fluvial erosion. In addition, soil erosion was predicted to be more sensitive to soil moisture than land coverage. A soil moisture level of 0.23–0.25 was determined to be the probable switch point from aeolian-to fluvial-dominant process or vice versa. Copyright © 2012 John Wiley & Sons, Ltd.