Bibliografie tematiche / Sediment export

Letteratura scientifica selezionata sul tema "Sediment export"

Autore: Grafiati

Pubblicato: 1 giugno 2024

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Articoli di riviste sul tema "Sediment export":

Line, Dan E., Deanna L. Osmond e Wesley Childres. "Nutrient Export from Agricultural Watersheds in the Piedmont and Coastal Plain, North Carolina". Transactions of the ASABE 62, n. 5 (2019): 1135–45. http://dx.doi.org/10.13031/trans.13052.

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Abstract. Nitrogen (N) and phosphorus (P) input and export rates were determined in six rural, predominantly agricultural watersheds located in the Piedmont and Coastal Plain regions of North Carolina. Water quality monitoring was conducted at the outlets for 2.3 to 8.0 years to determine the annual N and P export from each watershed. Total N and P input and export from five of the six watersheds were correlated, with only a no-till cropland watershed differing. The correlation showed that N and P exports increased by about 4.0% and 8.7%, respectively, of applied N and P for the range of applications rates, whereas dissolved N (NOx-N) export increased by 2.8% with increasing N application rates. Therefore, practices that reduce inputs, such as nutrient management, should result in similar percentage reductions in exports. The Small Watershed Nutrient Forecasting Tool (SWIFT) was used to forecast discharge, N, P, and sediment export from each of the six watersheds. For the no-till cropland watershed, the SWIFT-forecasted N and P export rates were more than 2.5 times those measured, while the sediment export rate was 72 times the measured value. Thus, these data showed that the SWIFT forecasts for N, P, and sediment export were poor for the no-till cropland watershed. For the pasture watershed, the SWIFT forecasts for N and sediment export agreed reasonably well with measured export; however, the forecasted P export was much less than measured. For the four mixed land use watersheds, the SWIFT forecasts for discharge, TN, and sediment were mostly greater than measured, and the forecasted TP export was less than measured for three of the four watersheds. Thus, as with many predicstion tools, SWIFT results must be used with caution. Keywords: Nutrient export, Nutrient management practice, Water quality monitoring.

Djunarsjah, E., M. M. Julian, A. A. Baskoro e N. R. Alfandi. "Spatial Modeling of Sediment Export Rate with Rainfall Variability Scenario in Peusangan Watershed, Aceh Province". IOP Conference Series: Earth and Environmental Science 925, n. 1 (1 novembre 2021): 012026. http://dx.doi.org/10.1088/1755-1315/925/1/012026.

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Abstract The rainfall affects the environmental interaction of watersheds and coastal areas. The high intensity of rain and water runoff will lift and carry particles in the watershed environment in the erosion process. This study estimates the total exports of sediment in Peusangan Watershed in the period 1995, 2005, 2015, and 2018 with rainfall variability scenarios. Total sediment exports are calculated from the erosion rate and sediment delivery ratio (SDR). Erosion rate modeling uses the RUSLE (Revised Universal Soil Loss Equation) that takes into account erosivity of rainfall, soil erodiability, topography, land cover, and land-use practices. While SDR is calculated based on its function as watershed area so that homogeneous value that causes the value of sediment export rate is directly proportional to the erosion rate value. The correlation between rainfall variability and sediment export rates is calculated based on rainfall variability correlation to erosion rate change. There is a direct relationship between rainfall variability and sediment export rates because the correlation coefficient is close to one. The rate of erosion in Peusangan watersheds falls into the light category based on the classification of erosion hazard levels according to the Ministry of Forestry in 1998. Based on the estimated rate of erosion and SDR, the total annual number of sediment exports obtained in the Peusangan watershed in 1995, 2005, 2015, and 2018 amounted to 1,066,027,426 tons, 909,914,623 tons, 1,075,759,133 tons, and 1,085,490,841 tons, respectively. Based on the spatial distribution of sediment export, Peusangan Watershed falls into the category of normal erosion.

Santos, Ana Isabel, Anabela Oliveira, José Paulo Pinto e M. Conceição Freitas. "Hydrodynamic and Sediment Transport Patterns in the Minho and Douro Estuaries (NW Portugal) Based on ADCP Monitoring Data: Part 1-Tidal Sediment Exchanges". Coasts 1, n. 1 (11 novembre 2021): 31–55. http://dx.doi.org/10.3390/coasts1010003.

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The tidal variability of the Minho and Douro lower estuaries (NW Portugal) water column structure was assessed at the semi-diurnal and fortnightly time scales under two contrasting seasonal river flow scenarios during the summer of 2005 and winter of 2006. Sediment fluxes inferred from calibrated ADCP acoustic backscatter revealed that, during spring tides and low runoff conditions, both estuaries act as sinks instead of sources of sediments into the inner shelf. Sediment export occurred during neaps, in both estuaries, when the river flow values were high enough to counteract the effect of the entering flood. No evidence of coarse sediment export into the inner shelf that would eventually nourish the littoral system could be inferred from these datasets.

Kulsoontornrat, Jiraporn, e Suwit Ongsomwang. "Suitable Land-Use and Land-Cover Allocation Scenarios to Minimize Sediment and Nutrient Loads into Kwan Phayao, Upper Ing Watershed, Thailand". Applied Sciences 11, n. 21 (5 novembre 2021): 10430. http://dx.doi.org/10.3390/app112110430.

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Human activity and land-use changes have affected the water quality of Kwan Phayao, Upper Ing watershed, due to the associated high sediment load and eutrophication. This study aims to identify suitable LULC allocation scenarios for minimizing sediment and nutrient export into the lake. For this purpose, the LULC status and change were first assessed, based on classified LULC data in 2009 and 2019 from Landsat images, using the SVM algorithm. Later, the land requirements of three scenarios between 2020 and 2029 were estimated, based on their characteristics, and applied to predict LULC change using the CLUE-S model. Then, actual LULC data in 2019 and predicted LULC data under three scenarios between 2020 and 2029 were used to estimate sediment and nutrient export using the SDR and NDR models. Finally, the ecosystem service change index identified a suitable LULC allocation for minimizing sediment or/and nutrient export. According to the results, LULC status and change indicated perennial trees and orchards, para rubber, and rangeland increased, while forest land and paddy fields decreased. The land requirements of the three scenarios provided reasonable results, as expected, particularly Scenario II, which adopts linear programming to calculate the land requirements for maximizing ecosystem service values. For sediment and nutrient export estimation under the predicted LULC for the three scenarios, Scenario II led to the lowest yield of sediment and nutrient exports, and provided the lowest average ESCI value among the three scenarios. Thus, the LULC allocation under Scenario II was chosen as suitable for minimizing sediment or/and nutrient export into Kwan Phayao. These results can serve as crucial information to minimize sediment and nutrient loads for land-use planners, land managers, and decision makers.

Nugroho, N. P. "Sediment export estimation from the catchment area of Lake Rawapening using InVEST model". IOP Conference Series: Earth and Environmental Science 950, n. 1 (1 gennaio 2022): 012072. http://dx.doi.org/10.1088/1755-1315/950/1/012072.

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Abstract Sedimentation is one of the main problems of the fifteen priority lakes in Indonesia, including Lake Rawapening. It has adverse impacts on lake, such as siltation that contribute to eutrophication and reduce the lake’s lifetime. Therefore, reducing sedimentation rate was set as one of the super-priority programs of the Lake Rescue Movement. Information on the spatial distribution of sediment export becomes important to implement the program effectively. This study aims to estimate the magnitude and the spatial distribution of sediment export from the catchment area of Lake Rawapening. The analysis was based on the Sediment Delivery Ratio sub-model. The results indicated that the total sediment export from the catchment area of Lake Rawapening is 501,628.6 tons/year. The largest export of sediment came from Galeh Sub-sub watershed, i.e., 161,091.7 tons/year (32.1% of the total sediment). However, Legi Sub-sub watershed has the highest average of sediment export per hectare, i.e., 42.9 tons/ha. High sediment export generally occurs in the upstream area with very steep slope, high rainfall, and dominated by dryland agriculture and vegetable farm land. Thus, efforts to reduce sediment export to Lake Rawapening should be focused on the hot-spot area, such as the upstream area of Legi Sub-sub watershed.

Ariagno, Coline, Caroline Le Bouteiller, Peter van der Beek e Sébastien Klotz. "Sediment export in marly badland catchments modulated by frost-cracking intensity, Draix–Bléone Critical Zone Observatory, SE France". Earth Surface Dynamics 10, n. 1 (21 gennaio 2022): 81–96. http://dx.doi.org/10.5194/esurf-10-81-2022.

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Abstract. At the interface between the lithosphere and the atmosphere, the critical zone records the complex interactions between erosion, climate, geologic substrate, and life and can be directly monitored. Long data records (30 consecutive years for sediment yields) collected in the sparsely vegetated, steep, and small marly badland catchments of the Draix–Bléone Critical Zone Observatory (CZO), SE France, allow analyzing potential climatic controls on regolith dynamics and sediment export. Although widely accepted as a first-order control, rainfall variability does not fully explain the observed interannual variability in sediment export. Previous studies in this area have suggested that frost-weathering processes could drive regolith production and potentially modulate the observed pattern of sediment export. Here, we define sediment export anomalies as the residuals from a predictive model with annual rainfall intensity above a threshold as the control. We then use continuous soil temperature data recorded at different locations over multiple years to highlight the role of different frost-weathering processes (i.e., ice segregation versus volumetric expansion) in regolith production. Several proxies for different frost-weathering processes have been calculated from these data and compared to the sediment export anomalies, with careful consideration of field data quality. Our results suggest that frost-cracking intensity (linked to ice segregation) can explain about half (47 %–64 %) of the sediment export anomalies. In contrast, the number of freeze–thaw cycles (linked to volumetric expansion) has only a minor impact on catchment sediment response. The time spent below 0 ∘C also correlates well with the sediment export anomalies and requires fewer field data to be calculated than the frost-cracking intensity. Thus, frost-weathering processes modulate sediment export by controlling regolith production in these catchments and should be taken into account when building predictive models of sediment export from these badlands under a changing climate.

Teng, Tse-Yang, Jr-Chuan Huang, Tsung-Yu Lee, Yi-Chin Chen, Ming-Young Jan e Cheng-Chien Liu. "Investigating Sediment Dynamics in a Landslide-Dominated Catchment by Modeling Landslide Area and Fluvial Sediment Export". Water 12, n. 10 (18 ottobre 2020): 2907. http://dx.doi.org/10.3390/w12102907.

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Few models are capable of simultaneously simulating the sequences of landslide occurrence and sediment export. Quantification of the temporarily stored sediment within the watershed plays a key role to link hillslope landslides with fluvial sediment export. In this study, two coupled models were proposed to simulate time-series total landslide area and the subsequent sediment export on a daily basis with only the inputs of rainfall and runoff. The landslide model considers per-existing and models new landslide, and the sediment transport model incorporates a sediment storage variable. The landslide and sediment transport model were well evaluated with Nash-Sutcliffe efficiency (EC) of 0.89 and logarithmic Nash-Sutcliffe efficiency (EClog) of 0.90, respectively, in the Tsengwen Reservoir watershed in southern Taiwan by using long-term observed data (2005–2015). It is found that reactivated landslides were up to 72% of the pre-landslide area, which contributed sediment comparable to the new landslide. Besides, the landslide model indicates that pre-landslide area controls the total landslide area but when rainfall is large it takes control in turn. With the simulation of sediment storage, the sediment transport model can well simulate the sediment export after the catastrophic event (typhoon Morakot in 2009). During the post-Morakot period, small rainfall and runoff can lead to high sediment export owing to the storage of Morakot-triggered landslide. This model will be a useful tool to diagnose the sediment dynamics in the watershed.

Chiang, Li-Chi, Yung-Chieh Wang e Ci-Jyun Liao. "Spatiotemporal Variation of Sediment Export from Multiple Taiwan Watersheds". International Journal of Environmental Research and Public Health 16, n. 9 (8 maggio 2019): 1610. http://dx.doi.org/10.3390/ijerph16091610.

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Soil erosion and landslide triggered by heavy rainfall are serious problems that have threatened water resources in Taiwan watersheds. This study investigated the relationship among streamflow, sediment load, sediment concentration and typhoon characteristics (path and rainfall amount) during 2000–2017 for nine gauging stations in five basins (Tamshui River basin, Zhuoshui River basin, Zengwen River basin, Gaoping River basin, and Hualien River basin) representing the diverse geomorphologic conditions in Taiwan. The results showed that streamflow and sediment load were positively correlated, and the correlation was improved when the sediment load data were grouped by sediment concentration. Among these basins, the Zhuoshui River basin has the highest unit-discharge sediment load and unit-area sediment load. The soil in the upstream was more erodible than the downstream soil during the normal discharge conditions, indicating its unique geological characteristics and how typhoons magnified sediment export. The spatiotemporal variation in sediment loads from different watersheds was further categorized by typhoons of different paths. Although typhoon path types matter, the Zhuoshui and Hualien River basin were usually impacted by typhoons of any path type. The results indicated that sediment concentration, the watershed soil characteristics, and typhoons paths were the key factors for sediment loads. This study can be useful for developing strategies of soil and water conservation implementation for sustainable watershed management.

Costa, Anna, Peter Molnar, Laura Stutenbecker, Maarten Bakker, Tiago A. Silva, Fritz Schlunegger, Stuart N. Lane, Jean-Luc Loizeau e Stéphanie Girardclos. "Temperature signal in suspended sediment export from an Alpine catchment". Hydrology and Earth System Sciences 22, n. 1 (22 gennaio 2018): 509–28. http://dx.doi.org/10.5194/hess-22-509-2018.

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Abstract. Suspended sediment export from large Alpine catchments (> 1000 km2) over decadal timescales is sensitive to a number of factors, including long-term variations in climate, the activation–deactivation of different sediment sources (proglacial areas, hillslopes, etc.), transport through the fluvial system, and potential anthropogenic impacts on the sediment flux (e.g. through impoundments and flow regulation). Here, we report on a marked increase in suspended sediment concentrations observed near the outlet of the upper Rhône River Basin in the mid-1980s. This increase coincides with a statistically significant step-like increase in basin-wide mean air temperature. We explore the possible explanations of the suspended sediment rise in terms of changes in water discharge (transport capacity), and the activation of different potential sources of fine sediment (sediment supply) in the catchment by hydroclimatic forcing. Time series of precipitation and temperature-driven snowmelt, snow cover, and ice melt simulated with a spatially distributed degree-day model, together with erosive rainfall on snow-free surfaces, are tested to explore possible reasons for the rise in suspended sediment concentration. We show that the abrupt change in air temperature reduced snow cover and the contribution of snowmelt, and enhanced ice melt. The results of statistical tests show that the onset of increased ice melt was likely to play a dominant role in the suspended sediment concentration rise in the mid-1980s. Temperature-driven enhanced melting of glaciers, which cover about 10 % of the catchment surface, can increase suspended sediment yields through an increased contribution of sediment-rich glacial meltwater, increased sediment availability due to glacier recession, and increased runoff from sediment-rich proglacial areas. The reduced extent and duration of snow cover in the catchment are also potential contributors to the rise in suspended sediment concentration through hillslope erosion by rainfall on snow-free surfaces, and increased meltwater production on snow-free glacier surfaces. Despite the rise in air temperature, changes in mean discharge in the mid-1980s were not statistically significant, and their interpretation is complicated by hydropower reservoir management and the flushing operations at intakes. Overall, the results show that to explain changes in suspended sediment transport from large Alpine catchments it is necessary to include an understanding of the multitude of sediment sources involved together with the hydroclimatic conditioning of their activation (e.g. changes in precipitation, runoff, air temperature). In addition, this study points out that climate signals in suspended sediment dynamics may be visible even in highly regulated and human-impacted systems. This is particularly relevant for quantifying climate change and hydropower impacts on streamflow and sediment budgets in Alpine catchments.

Tofelde, Stefanie, Sara Savi, Andrew D. Wickert, Aaron Bufe e Taylor F. Schildgen. "Alluvial channel response to environmental perturbations: fill-terrace formation and sediment-signal disruption". Earth Surface Dynamics 7, n. 2 (1 luglio 2019): 609–31. http://dx.doi.org/10.5194/esurf-7-609-2019.

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Abstract. The sensitivity of fluvial systems to tectonic and climatic boundary conditions allows us to use the geomorphic and stratigraphic records as quantitative archives of past climatic and tectonic conditions. Thus, fluvial terraces that form on alluvial fans and floodplains as well as the rate of sediment export to oceanic and continental basins are commonly used to reconstruct paleoenvironments. However, we currently lack a systematic and quantitative understanding of the transient evolution of fluvial systems and their associated sediment storage and release in response to changes in base level, water input, and sediment input. Such knowledge is necessary to quantify past environmental change from terrace records or sedimentary deposits and to disentangle the multiple possible causes for terrace formation and sediment deposition. Here, we use a set of seven physical experiments to explore terrace formation and sediment export from a single, braided channel that is perturbed by changes in upstream water discharge or sediment supply, or through downstream base-level fall. Each perturbation differently affects (1) the geometry of terraces and channels, (2) the timing of terrace cutting, and (3) the transient response of sediment export from the basin. In general, an increase in water discharge leads to near-instantaneous channel incision across the entire fluvial system and consequent local terrace cutting, thus preserving the initial channel slope on terrace surfaces, and it also produces a transient increase in sediment export from the system. In contrast, a decreased upstream sediment-supply rate may result in longer lag times before terrace cutting, leading to terrace slopes that differ from the initial channel slope, and also lagged responses in sediment export. Finally, downstream base-level fall triggers the upstream propagation of a diffuse knickzone, forming terraces with upstream-decreasing ages. The slope of terraces triggered by base-level fall mimics that of the newly adjusted active channel, whereas slopes of terraces triggered by a decrease in upstream sediment discharge or an increase in upstream water discharge are steeper compared to the new equilibrium channel. By combining fill-terrace records with constraints on sediment export, we can distinguish among environmental perturbations that would otherwise remain unresolved when using just one of these records.

Più fonti

Tesi sul tema "Sediment export":

Mullenbach, Beth Lee. "Characterization of modern off-shelf sediment export on the Eel margin, Northern California /". Thesis, Connect to this title online; UW restricted, 2002. http://hdl.handle.net/1773/10969.

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Stewart, George Russell. "Water quality improvements in the Upper North Bosque River watershed due to phosphorous export through turfgrass sod". Texas A&M University, 2004. http://hdl.handle.net/1969.1/1428.

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The Upper North Bosque River (UNBR) watershed is under a Total Maximum Daily Load (TMDL) mandate to reduce Phosphorus (P) due to excess nutrients in the watershed. To address these problems, Texas A&M University researchers have developed a turfgrass sod Best Management Practice (BMP) to remove excess nutrients from impaired watersheds. Turfgrass harvest of manure fertilized sod removes a thin layer of topsoil with most of the manure applied P. Plot and field scale research has demonstrated the effectiveness of turfgrass to remove manure phosphorus (P). In order to assess the impact of the turfgrass BMP on a watershed scale, the Soil and Water Assessment Tool (SWAT) was used to predict water quality in the UNBR watershed. The SWAT model was modified to incorporate turfgrass harvest routines to predict manure and soil P export through turfgrass sod and soil during harvest. SWAT simulations of the BMP predicted stream load reductions of 20 to 36% for P loads in the UNBR depending on the implementation scenario, an average reduction of 31% for total N and 16.7% for sediment for all the scenarios, at the watershed outlet. The SWAT model also predicted up to 176 kg/ha P removed per sod harvest when fertilized with 100 kg manure P/ha, and 258 kg/ha of P removed per sod harvest when the manure P application rate was 200 kg/ha. In addition, depending on the implementation scenario, the turfgrass BMP could export between 262 and 784 metric tons of P out of the UNBR watershed every year. Manure fertilized turfgrass has the advantage of slow releasing nutrients from the composted dairy manure, so it would not require any additional P for life. This means reduced urban non-point source pollution and lower maintenance cost compared to regular sod. These modeling simulations complement the wealth of research that shows the effectiveness of the turfgrass BMP.

Carter, Samantha Cassie. "Improving our understanding of the marine barium cycle and constructing a new archive of erosion and sediment transport". The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1593602009469204.

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Hurtado, Shanty Navarro. "A influência da implantação de um terminal aquaviário na dinâmica sedimentar local da Baía de Guanabara". Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/21/21133/tde-23092009-103654/.

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A Baía da Guanabara vem sofrendo alterações na sua bacia de drenagem desde o início do século XIX que resultaram em acentuada degradação ambiental. O presente trabalho discute a influência da implantação de um Terminal Aquaviário de Gás Natural Liquefeito (GNL) na Baía, e suas possíveis influências nos processos de sedimentação local e/ou re-disponibilização de sedimentos de fundo, e possíveis contaminantes associados. Os resultados dos modelos matemáticos mostram que as maiores velocidades das plumas termicas que atingem o fundo são em média 0,46 m3/s para as simulações de verão e 0,47 m3/s para as simulações de inverno, sendo que são necessários pelo menos de 0,50 m3/s para uma corrente erodir o fundo, porem velocidades na faixa de 20 a 50 m3/s são suficientes para causar erosão de sedimentos finos inconsolidados. Sendo assim, a influência das plumas térmicas geradas no processo de re-gaseificação do GNL é de pequena magnitude, e suas correntes só conseguem exportar estes sedimentos para distancias inferiores a 1000 m. Em relação a re-disponibilização de contaminantes associados aos sedimentos de fundo se mostrou pouco provável, dado o fato da qualidade dos sedimentos apresentarem, diferente da água, baixa concentração de contaminantes e da baixa competência de erosão, que eles tenham competência para erodir sedimentos consolidados.
Since the beginning of the XIX century, interventions on the Guanabara\'s Bay drainage basin result in severe environmental degradation. This work aimed to analyze the implementation of an Aquaviary Terminal of Liquefied Natural Gas (LNG), and its putative consequences on the local sedimentation processes, and the availability and possible associated contaminants of the bottom sediments. According to the mathematical models developed, the means of the greatest speeds of the thermal plumes that reach the bottom are 0.46m3/s for the summer simulations and 0.47m3/s for the winter. However, for a current to be able to erode the bottom it must be of at least 50m3/s. Currents with speeds ranging from 20 to 50m3/s are sufficient only to cause the erosion of fine and non-consolidated sediment. Therefore, the thermal plumes generated in the process of re-gasification of the LNG are of little magnitude, and will not be able to export these sediments to any distance greater than 1000 meters. The re-availability of the contaminants associated with the bottom sediments is not likely, once these sediments, differently from the water, showed little concentration of contaminants. In addition, with the low erosion capacity of the currents generated, the consolidated sediments are not likely to be eroded.

Song, Layheang. "Usage des terres, ruissellement de surface, érosion des sols : analyse multi-échelles de l'impact des plantations de teck dans un agro-écosystème montagneux tropical humide". Electronic Thesis or Diss., Toulouse 3, 2021. http://www.theses.fr/2021TOU30188.

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L'érosion des sols est pourtant connue comme l'un des problèmes environnementaux les plus préoccupants au monde. L'érosion des sols est particulièrement et de plus en plus entraînée par les activités anthropiques dans le cadre du changement climatique. En RDP lao, un pays tropical, l'érosion des sols est due de manière significative à une gestion inappropriée des terres sur les terrains en pente. Le Houay Pano, un bassin versant cultivé du nord de la RDP lao, est exposé à l'érosion des sols, en particulier après la conversion de la culture itinérante en plantation de teck. La mauvaise gestion des terres en défrichant le sous couvert végétal sous la plantation de teck est considérée comme une cause sous-jacente du coefficient de ruissellement (Rc) plus élevé et de l'érosion des sols. Certaines mesures d'atténuation telles que le sous couvert végétal et la végétation rivulaire sont suggérées pour atténuer l'érosion des sols. Cependant, la mesure d'atténuation de l'érosion des sols et l'effet de la gestion de l'utilisation des terres sur le ruissellement de surface (SR) et la perte en sols/rendement de sédiments (Sl) à plusieurs échelles dans la plantation de teck ne sont pas entièrement évalués. Dans ce contexte, nous émettons l'hypothèse que le sous couvert végétal et l'herbe rivulaire atténuent l'érosion du sol dans la plantation d'arbres à teck et que les plantations d'arbres à teck ont ??des impacts sur SR et Sl entraînés par des processus dominants (l'érosion en nappe, l'érosion linéaire et le dépôt de sédiment) sur diverses échelles spatiales. Par conséquent, les objectifs fixés pour ce travail sont : (1) d'évaluer l'effet de la gestion du sous couvert végétal sur le ruissellement de surface et la perte en sols dans la plantation de teck à l'échelle de la micro-parcelle ; (2) d'évaluer la capacité des zones tampons d'herbes rivulaires à atténuer SR et Sl, et d'évaluer leur efficacité de piégeage de l'eau et des sédiments dans les plantations de teck sans sous couvert végétal à l'échelle du versant ; et (3) d'évaluer l'effet de la plantation de teck sur SR et Sl à diverses échelles spatiales (échelles de micro-parcelle, de versant incluant micro-bassin versant, et de bassin versant) dans un bassin versant tropical montagneux à utilisations mixtes de terre. Dans cette étude, le village de Ban Kokngew et le bassin versant d'Houay Pano ont été sélectionnés comme zones d'étude expérimentale pendant la saison des pluies. Des micro-parcelles, des pièges Gerlach et des déversoirs ont été utilisés pour estimer SR et Sl à chaque échelle. Nous avons suivi le modèle TEST développé pour l'érosion en nappe, qui nécessite quelques paramètres, pour évaluer Sl sur la micro-parcelle et le mettre en hautes échelles spatiales pour prédire Sl à l'échelle du versant et du bassin versant. Dans une étude réalisée en 2017 dans les plantations de teck de Ban Kokngew à l'échelle micro-parcelle, nous avons montré que Rc et Sl (23%, 381 Mg·km-2, respectivement) sous teck avec sous couvert végétal étaient inférieurs à ceux sous teck sans sous couvert végétal (60 % et 5455 Mg·km-2, respectivement). Par conséquent, l'atténuation de l'érosion des sols par le maintien du sous couvert végétal sous la plantation de teck réduit Sl de 14 fois. [...]
Soil erosion is yet known as one of the most concerning problems of the environment in the world. Soil erosion is particularly and increasingly driven by anthropogenic activities under the changing climate. In Lao PDR, a tropical country, soil erosion is significantly due to inappropriate land management on the sloping land. The Houay Pano, a cultivated catchment of the northern Lao PDR, is prone to soil erosion, particularly after the conversion from shifting cultivation to teak tree plantation. Land mismanagement by clearing the understory under the teak tree plantation is considered as an underlying cause of higher runoff coefficient (Rc) and soil erosion. Some mitigations such as understory and riparian vegetation are suggested for alleviating soil erosion. However, the mitigation measure of soil erosion and the effect of land use management on surface runoff (SR) and soil loss/sediment yield (Sl) on multiple scales in the teak tree plantation are not fully assessed. In this context, we hypothesize that understory and riparian grass mitigate the soil erosion in the teak tree plantation and that teak tree plantation impacts on SR and Sl driven by dominant processes (inter rill erosion, linear erosion, and deposition) on various spatial scales. Therefore, the objectives set out for this work are: (1) to assess the effect of understory management on SR and Sl in the teak tree plantation on the microplot scale; (2) to assess the ability of riparian grass buffers to mitigate SR and Sl, and to assess their water and sediment trapping efficiencies in the teak tree plantations with no understory on the hillslope scale; and (3) to assess the effect of teak tree plantation on SR and Sl on various spatial scales (microplot, hillslope including micro-catchment, and catchment scales) in a mixed land uses mountainous tropical catchment. In this study, Ban Kokngew village and Houay Pano catchment were selected as experimental study areas during the rainy season. Microplots, Gerlach traps, and weirs were used to estimate SR and Sl on each scale. We followed the TEST model developed for inter rill erosion, which requires a few parameters, to assess Sl on the microplot and upscale it to predict Sl on the hillslope and catchment scale. In a study performed in 2017 in the teak tree plantations of Ban Kokngew on the microplot scale, we showed that Rc and Sl (23%, 381 Mg·km-2, respectively) under teak tree with understory were less than those under teak tree with no understory (60% and 5455 Mg·km-2, respectively). Hence, soil erosion mitigation by keeping the understory under teak tree plantation reduces Sl by 14 times. In a study performed in 2014 in the teak tree plantations of Houay Pano on both the microplot and the hillslope scales, we showed that leaving the riparian grass buffer of at least 6 m could limit SR and Sl discharging downstream during small storms (24-hour rainfall < 54.8 mm) with the trapping efficiency up to 88%. Lastly, in a study performed in 2014 in the teak tree plantations of Houay Pano on various scales, we showed that SR and Sl were significantly higher (p-value < 0.05) in the teak-dominated micro-catchment than in the mixed-land-use micro-catchment. SR and Sl decreased from the microplot (122 - 196 mm, 275 - 1065 Mg·km-2, respectively) to the micro-catchment (24 - 188 mm, 95 - 3635 Mg·km-2, respectively) and catchment scale (33 mm, 236 Mg·km-2, respectively), except that Sl in teak tree plantation increased from the microplot (1065 Mg·km-2) to the micro-catchment scale (3635 Mg·km-2). [...]

Burton, Andrew Mark. "Expert systems to assist in the redevelopment of contaminated land". Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.326779.

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Hemingway, Jordon Dennis. "Understanding terrestrial organic carbon export : a time-series approach". Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/109054.

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Abstract (sommario):

Thesis: Ph. D., Joint Program in Chemical Oceanography (Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2017.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 169-190).
Terrestrial organic carbon (OC) erosion, remineralization, transport through river networks, and burial in marine sediments is a major pathway of the global carbon cycle. However, our ability to constrain these processes and fluxes is largely limited by (i) analytical capability and (ii) temporal sampling resolution. To address issue (i), here I discuss methodological advancements and data analysis techniques for the Ramped PyrOx serial oxidation isotope method developed at WHOI. Ramped-temperature pyrolysis/oxidation coupled with the stable carbon (¹²C, ¹³C) and radiocarbon (¹⁴C) analysis of evolved CO₂ is a promising tool for understanding and separating complex OC mixtures. To quantitatively investigate distributions of OC source, reservoir age, and chemical structure contained within a single sample, I developed a kinetic model linking RPO-derived activation energy, ¹³C composition, and radiocarbon content. This tool provides a novel method to fundamentally address the unknown relationship between OC remineralization rates and chemical structure in various environmental settings. To address issue (ii), I additionally present results from time-series sample sets collected on two end-member systems: the Congo River (Central Africa) and the LiWu River (Taiwan). For the Congo River, bulk and plant-wax-lipid ¹³C compositions indicate that a majority of particulate OC is consistently derived from downstream, C₃-dominated rainforest ecosystems. Furthermore, bulk radiocarbon content and microbial lipid molecular distributions are strongly correlated with discharge, suggesting that pre-aged, swamp-forest-derived soils are preferentially exported when northern hemisphere discharge is highest. Combined, these results provide insight into the relationship between hydrological processes and fluvial carbon export. Lastly, I examined the processes controlling carbon source and flux in a set of soils and time-series fluvial sediments from the LiWu River catchment located in Taiwan. A comparison between bedrock and soil OC content reveals that soils can contain significantly less carbon than the underlying bedrock, suggesting that this material is remineralized to CO₂ prior to soil formation. Both the presence of bacterial lipids and a shift toward lower activation energy of ¹⁴C-free OC contained in soil saprolite layers indicate that this process is microbially mediated and that microbial respiration of rock-derived OC likely represents a larger geochemical flux than previously thought. The results presented in this thesis therefore provide novel insight into the role of rivers in the global carbon cycle as well as their response to environmental perturbations.
by Jordon Dennis Hemingway
Ph. D.

Causse, Jean. "Temporalité des transferts de nutriments dans les bassins versants à algues vertes". Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1B012/document.

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En Bretagne, les « marées vertes » sont récurrentes depuis le début des années 70 et occupent une place importante dans le débat public en terme sanitaire, politique et économique. Lors de cette thèse, une large revue bibliographique a été réalisée sur l’export d’azote et une méthodologie innovante a été mise en place afin d’étudier la variabilité spatio-temporelle de l’export de nutriments dans 2 bassins versants à algues vertes à une échelle intra-annuelle et pendant des évènements extrêmes (évènements pluvieux, période touristique de basses eaux,…). Les bassins versants sélectionnés pour les expérimentations de terrain sont l’Ic et le Frémur (Côtes d’Armor). 3 types d’expérimentations ont été réalisées sur ces bassins versants : 1) Des campagnes de prélèvements ponctuels par temps sec et par temps de pluie (32 stations, 27 campagnes) ; 2) des prélèvements automatiques en crue (3 stations, 8 crues) ; et 3) la mesure haute fréquence (2 stations, en continu). Les paramètres hydrologiques et physico-chimiques classiques, les matières en suspension, les spectres UV et toutes les formes de macronutriments (carbone, azote, phosphore) ont été analysés lors de ces expérimentations. Les résultats obtenus confirment pour une part un certain nombre de résultats de la littérature. D’autre part, il met en lumière la relation carbone/nitrates, jusqu’à présent peu étudiée à différentes échelles spatio-temporelles et pendant des évènements pluvieux, qui semble pourtant primordiale dans la compréhension des phénomènes d’export de nitrates à l’échelle de l’année. Enfin, l’analyse de toutes les formes de nutriments révèle l’importance des formes particulaires issues de l’érosion des sols. Ces résultats soulèvent de nombreuses questions de recherche qui mériteraient un approfondissement afin d’améliorer la connaissance des transferts de nutriments dans les bassins versants et prioriser les actions de remédiations. Les perspectives de ce travail sont à la fois scientifiques et pratiques. Au niveau scientifique, les efforts de recherche sur la relation carbone/nitrate et l’identification de la fraction de carbone organique assimilable par les organismes dénitrifiants doivent être poursuivis. De même, l’amélioration des connaissances sur l’export de nutriments en crue passe par l’identification précise des sources de nutriments particulaires pendant les crues printanières. Au niveau pratique, il doit contribuer à l’amélioration des pratiques agricoles, à la reconnaissance de l’intérêt des zones humides naturelles et à l’amélioration des types de traitement utilisés par les stations d’épuration. Les résultats obtenus lors de cette étude devraient notamment être mis en relation avec la dynamique des nutriments observée dans l’estran pendant la période de développement des algues vertes. Enfin, un effort d’amélioration de l’accès à certains type de données sur les bassins versants est nécessaire afin d’améliorer la compréhension des transferts de nutriments
In Brittany (Western France), "green tides" are recurrent since the early 70s and have an important place in public debate in health, political and economic terms. In this thesis, a wide bibliographic review was performed on the export of nitrogen, and an innovative methodology has been set up to study the spatial and temporal variability of nutrient export in two coastal watersheds on an intra-annual basis and during extreme events (rainfall events, tourist periods of low water, ...). Watersheds selected for the field experiments are Ic and Frémur (Côtes d'Armor). 3 types of experiments were performed on these watersheds: 1) Campaigns of grab samples by dry and wet weather (32 stations, 27 campaigns); 2) automatic sampling during floods (3 stations, 8 floods); and 3) high frequency measurement (2 stations, continuous). Conventional hydrological and physicochemical parameters, suspended solids, UV spectra and all forms of macronutrients (carbon, nitrogen, phosphorus) were analyzed during these experiments. The results confirm in part a number of results of the literature. Furthermore, it highlights the relationship carbon / nitrates far little studied at different spatial and temporal scales and during rainfall events, which however seems to be crucial in understanding of nitrate export. Finally, the analysis of all forms of nutrients reveals the importance of particulate forms from soil erosion. These results raise many research questions that merit further development in order to improve knowledge on nutrient transfers in watersheds and prioritize remediation actions. The prospects of this work are both scientific and practical. At the scientific level, research efforts on the relationship carbon / nitrate and identification of the assimilable fraction of organic carbon by denitrifying organisms must be continued. Similarly, the knowledge on nutrient export must be improved through the precise identification of particulate nutrient sources during the spring floods. On a practical level, it should contribute to the improvement of agricultural practices, the recognition of the interest of natural wetlands and improvement of the types of treatment used by treatment plants. The results obtained in this study should in particular be linked to the dynamics of nutrients in the foreshore observed during the development of green algae. Finally, an effort to improve access to certain types of data on watersheds is needed to improve understanding of nutrient transfers

Emmermann, Peter. "Mineralogy, geochemistry and microfacies of late Quaternary periplatform sediments carbonate export cycles and secondary processes - Sanganeb Atoll and Abington Reef, Sudan, Central Red Sea = Mineralogie, Geochemie und Mikrofazies spätquartärer Periplattformsedimente /". [S.l. : s.n.], 2000. http://e-diss.uni-kiel.de/diss%/d364.pdf.

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Butler, David Michael. "Runoff, sediment, and nutrient export from manured riparian pasture as affected by simulated rain and ground cover". 2004. http://www.lib.ncsu.edu/theses/available/etd-05312004-233542/unrestricted/etd.pdf.

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Libri sul tema "Sediment export":

James, William F. Wind-induced sediment resuspension and export in Marsh Lake, Western Minnesota. [Vicksburg, Miss: U.S. Army Engineer Waterways Experiment Station, 1995.

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R, Patin Thomas, e Water Resources Support Center (U.S.), a cura di. Management of bottom sediments containing toxic substances: Proceedings of the 14th US/Japan Experts Meeting, 27 February-1 March 1990, Yokohoma, Japan. [Washington, DC]: US Army Corps of Engineers, Water Resources Support Center, 1992.

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R, Patin Thomas, e Water Resources Support Center (U.S.), a cura di. Management of bottom sediments containing toxic substances: Proceedings of the 14th US/Japan Experts Meeting, 27 February-1 March 1990, Yokohama, Japan. [Washington, DC]: US Army Corps of Engineers, Water Resources Support Center, 1992.

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U.S.-Japan Experts' Meeting on the Management of Bottom Sediments Containing Toxic Substances (9th 1983 Jacksonville). Management of bottom sediments containing toxic substances: Proceedings of the 9th U.S./Japan Experts Meeting, 17-19 October 1983, Jacksonville, Florida. A cura di Patin Thomas R, Dredging Operations Technical Support Program (U.S. Army Engineer Waterways Experiment Station. Environmental Laboratory), U.S. Army Engineer Waterways Experiment Station., Water Resources Support Center (U.S.). e Japan Unʼyushō. Ft. Belvoir, Va: Water Resources Support Center, 1985.

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Smol, J. P. Pollution of lakes and rivers: A paleoenvironmental perspective. London: Arnold, 2002.

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Smol, J. P. Pollution of lakes and rivers: A paleoenvironmental perspective. 2^a ed. Malden, MA: Blackwell Pub., 2008.

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New Jersey. Legislature. General Assembly. Solid and Hazardous Waste Committee. Committee meeting of Assembly Solid and Hazardous Waste Committee: Testimony from concerned public policy makers and environmental experts on the appropriate role GE should play in the cleanup of the Hudson River. Trenton, N.J: Solid and Hazardous Waste Committee, 2001.

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Simpson, Stuart, e Graeme Batley, a cura di. Sediment Quality Assessment. CSIRO Publishing, 2016. http://dx.doi.org/10.1071/9781486303854.

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Contaminated sediments represent an ongoing threat to the health of aquatic ecosystems. The assessment of sediment quality is, therefore, an important concern for environmental regulators. Sediment quality guidelines are now well established in regulatory frameworks worldwide; however, practical guidance that covers all of the key aspects of sediment quality assessment is not readily available. In 2005, CSIRO published its highly cited Handbook for Sediment Quality Assessment. In the ensuing period, the science has advanced considerably. This practical guide is a revised and much expanded second edition, which will be a valuable tool for environmental practitioners. Written by experts in the field, it provides coverage of: sediment sampling; sample preparation; chemical analysis; ecotoxicology; bioaccumulation; biomarkers; and ecological assessment. In addition, detailed appendices describe protocols for many of the tests to be used.

Taberlet, Pierre, Aurélie Bonin, Lucie Zinger e Eric Coissac. Some early landmark studies. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198767220.003.0011.

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Chapter 11 entitled “Some early landmark studies” revisits several seminal articles that paved the way for the field of eDNA research. It first evokes the paper that first coined the expression “environmental DNA” in the late 1980s. Then, it describes how eDNA was first exploited in the early 1990s to reveal an unsuspected microbial diversity that morphology- or cultivation-based methods had failed to reach. In the late 1990s, microbiologists began to explore in several pioneer papers the functional insight provided by “metagenomes” (i.e., the collective genomes found in eDNA samples). In the 2000s, eDNA analysis was finally extended to macroorganisms. Chapter 11 reports such a use in two very different contexts (i.e., the detection of a contemporary invasive species, the bullfrog, and the reconstruction of past plant and animal communities from sediment and permafrost samples).

Thompson, Lonnie G., e Alan L. Kolata. Twelfth Century AD. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780199329199.003.0008.

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Climate is a fundamental and independent variable of human existence. Given that 50 percent of the Earth’s surface and much of its population exist between 30oN and 30oS, paleoenvironmental research in the Earth’s tropical regions is vital to our understanding of the world’s current and past climate change. Most of the solar energy that drives the climate system is absorbed in these regions. Paleoclimate records reveal that tropical processes, such as variations in the El Niño-Southern Oscillation (ENSO), have affected the climate over much of the planet. Climatic variations, particularly in precipitation and temperature, play a critical role in the adaptations of agrarian cultures located in zones of environmental sensitivity, such as those of the coastal deserts, highlands, and altiplano of the Andean region. Paleoclimate records from the Quelccaya ice cap (5670 masl) in highland Peru that extend back ~1800 years show good correlation between precipitation and the rise and fall of pre-Hispanic civilizations in western Peru and Bolivia. Sediment cores extracted from Lake Titicaca provide independent evidence of this correspondence with particular reference to the history of the pre-Hispanic Tiwanaku state centered in the Andean altiplano. Here we explore, in particular, the impacts of climate change on the development and ultimate dissolution of this altiplano state.

Capitoli di libri sul tema "Sediment export":

Christiansen, Christian, Ierotheos Zacharias e Torben Vang. "Storage, redistribution and net export of dissolved and sediment-bound nutrients, Vejle Fjord, Denmark". In Sediment/Water Interactions, 47–57. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2783-7_4.

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Kronvang, B., R. Grant e A. L. Laubel. "Sediment and Phosphorus Export from a Lowland Catchment: Quantification of Sources". In The Interactions Between Sediments and Water, 465–76. Dordrecht: Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-011-5552-6_48.

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Hansell, D. A., e J. N. Downs. "Solubilization of Organic Particles Collected in Sediment Traps: Effect on Export Production Estimates". In Primary Productivity and Biogeochemical Cycles in the Sea, 512–13. Boston, MA: Springer US, 1992. http://dx.doi.org/10.1007/978-1-4899-0762-2_40.

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Frank, M., R. Gersonde e A. Mangini. "Sediment Redistribution, 230Thex- Normalization and Implications for the Reconstruction of Particle Flux and Export Paleoproductivity". In Use of Proxies in Paleoceanography, 409–26. Berlin, Heidelberg: Springer Berlin Heidelberg, 1999. http://dx.doi.org/10.1007/978-3-642-58646-0_16.

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Nieminen, Mika, Annu Kaila, Markku Koskinen, Sakari Sarkkola, Hannu Fritze, Eeva-Stiina Tuittila, Hannu Nousiainen et al. "Natural and Restored Wetland Buffers in Reducing Sediment and Nutrient Export from Forested Catchments: Finnish Experiences". In The Role of Natural and Constructed Wetlands in Nutrient Cycling and Retention on the Landscape, 57–72. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-08177-9_5.

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Kriet, Keith, Bruce J. Peterson e Teresa L. Corliss. "Water and sediment export of the upper Kuparuk River drainage of the North Slope of Alaska". In Toolik Lake, 71–81. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2720-2_7.

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Ries, David G., e Robert L. Burns. "Expert Opinions in Environmental Litigation Gatekeeping 10 Years After Daubert". In Contaminated Soils, Sediments and Water, 433–55. Boston, MA: Springer US, 2005. http://dx.doi.org/10.1007/0-387-23079-3_28.

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Langone, L., M. Frignani, J. K. Cochran e M. Ravaioli. "Scavenging Processes and Export Fluxes Close to a Retreating Seasonal Ice Margin (Ross Sea, Antarctica)". In The Interactions Between Sediments and Water, 705–15. Dordrecht: Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-011-5552-6_72.

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Ortega, Ana I., Francisco Ruiz, Miguel A. Martín, Alfonso Benito-Calvo, Marco Vidal, Lucía Bermejo e Theodoros Karampaglidis. "Prehistoric Human Tracks in Ojo Guareña Cave System (Burgos, Spain): The Sala and Galerías de las Huellas". In Reading Prehistoric Human Tracks, 317–42. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-60406-6_17.

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AbstractIn 1969, members of Grupo Espeleológico Edelweiss discovered the Sala and Galerías de las Huellas in Ojo Guareña Cave system (Burgos, Spain). These contained hundreds of ancient human footprints, preserved in the soft sediment on the floor. These footprints represent the tracks of a small group of people who walked barefoot through these complex passages in the cave. Owing to the difficult compatibility of the documentation and preservation of these prints, it was not possible to study them before the development of new non-invasive remote sensing techniques. However, since 2012 optical laser scanning and digital photogrammetry have been used in Galerías de las Huellas, in combination with GIS techniques, to obtain a model of the cave floor, where the footprints and their internal morphology can be observed in detail. We have identified over 1000 prehistoric human footprints and at least 18 distinct trackways through the passages, which could have been left by around 8–10 individuals. Since 2016, an archaeological field study has been conducted in this sector, in order to determine and explore its surrounding area and find other archaeological evidence that may be directly associated with these tracks. Numerous remains of torches are preserved on the walls and floor in the immediate surroundings of the footprint sites. Some of them have been dated, which has revealed the intensive use of this underground landscape from the Upper Palaeolithic to the Mesolithic-Neolithic. However, the remains in Sala and Galerías de las Huellas date solely to the Chalcolithic, around 4300 calBP.

Bianchi, Thomas S. "Sources and Distribution of Sediments". In Biogeochemistry of Estuaries. Oxford University Press, 2006. http://dx.doi.org/10.1093/oso/9780195160826.003.0014.

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The uplift of rocks above sea level on the Earth’s surface over geological time, produces rock material that can be altered into soils and sediments by weathering processes. Over geological time, a fraction of sediments can be sequestered for storage in the ocean basins—with most of it stored in the coastal margin. However, much of this material is modified via processing in large river estuarine systems which can ultimately affect the long-term fate of these terrigenous materials. Sediments produced from weathering of igneous, metamorphic, and sedimentary rocks are principally transported to the oceans through river systems of the world. The major routes of sediment transport from land to the open ocean can simply be illustrated through the following sequence: streams, rivers, estuaries, shallow coastal waters, canyons, and the abyssal ocean. It should be noted that significant and long-term storage occurs in river valleys and floodplains (Meade, 1996). Submarine canyons are also thought to be temporary storage sites for land-derived sediments; however, episodic events such as turbidity currents and mud slides can move these sediments from canyons to the abyssal ocean (more details on coastal margin transport to the deep ocean are provided in chapter 16). The annual sediment flux from rivers to the global ocean is estimated to range from 18 to 24 × 109 metric tonnes (Milliman and Syvitski, 1992). Conversely, estuaries will eventually fill-in with fluvial inputs of sediments over time, and ultimately reach an equilibrium whereby export and import of sediment supply are balanced (Meade, 1969). For example, recent studies have shown that sediment accumulation in the Hudson River estuary, both short (Olsen et al., 1978) and long term (Peteet and Wong, 2000), is in equilibrium with sea level rise. More specifically, it is believed that river flow controls the direction of sediment flux in the Hudson, while variations in spring-neap tidal amplitude control the magnitude (Geyer et al., 2001). Weathering is typically separated into two categories: physical and chemical. Physical weathering involves the fragmentation of parent rock materials and minerals through processes such as freezing, thawing, heating, cooling, and bioturbation (e.g., endolithic algae, fungi, plant roots, and earthworms).

Atti di convegni sul tema "Sediment export":

"Assessment of the GBR Source Catchments model to estimate fine-sediment streambank erosion and sediment export". In 22nd International Congress on Modelling and Simulation. Modelling and Simulation Society of Australia and New Zealand (MSSANZ), Inc., 2017. http://dx.doi.org/10.36334/modsim.2017.l22.baheerathan.

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Shapley, Mark D., Glenn D. Thackray, Bruce P. Finney e Eric M. Johnson. "SEISMOGENIC SEDIMENT REDISTRIBUTION AND EXPORT AT REDFISH LAKE, IDAHO, DRIVEN BY HOLOCENE FAULTING". In GSA Annual Meeting in Seattle, Washington, USA - 2017. Geological Society of America, 2017. http://dx.doi.org/10.1130/abs/2017am-306215.

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Beck, William, Peter L. Moore, Keith Schilling, Calvin Wolter e Tom Isenhart. "FLOODPLAIN SEDIMENTATION TRENDS AND IMPLICATIONS FOR WATERSHED SEDIMENT AND PHOSPHORUS EXPORT, WALNUT CREEK, IOWA". In 52nd Annual North-Central GSA Section Meeting - 2018. Geological Society of America, 2018. http://dx.doi.org/10.1130/abs/2018nc-313208.

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Ryan, Sophia, Beverley Wemple e Donald S. Ross. "QUANTIFYING STREAM PHOSPHORUS DYNAMICS AND TOTAL SUSPENDED SEDIMENT EXPORT IN FORESTED WATERSHEDS IN VERMONT". In 53rd Annual GSA Northeastern Section Meeting - 2018. Geological Society of America, 2018. http://dx.doi.org/10.1130/abs/2018ne-311131.

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Bosse-Demers, Thomas, Charles Gobeil, Bennet Juhls, Martine Lizotte, Atsushi Matsuoka, Raoul-Marie Couture, Audrey Gaudy e Santiago Mareque. "Lanthanides as tracers of sediment export from the Mackenzie River to coastal and abyssal Arctic Ocean". In Goldschmidt2023. France: European Association of Geochemistry, 2023. http://dx.doi.org/10.7185/gold2023.17001.

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Fordham, Edward, e Allison Pfeiffer. "CONNECTING HEADWATER DEBRIS FLOWS TO SUSPENDED SEDIMENT EXPORT IN THE LOWER SUIATTLE RIVER, GLACIER PEAK, WASHINGTON STATE". In GSA Connects 2021 in Portland, Oregon. Geological Society of America, 2021. http://dx.doi.org/10.1130/abs/2021am-371170.

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Goldsmith, Steven T., Devin F. Smith, Lisa J. Rodrigues, Eric J. Wagner, Peleg Kremer e Ryan P. Moyer. "EVALUATING THE RELATIONSHIP AMONG LAND USE CHANGE, SEDIMENT AND NUTRIENT EXPORT, WITH NEARSHORE CORAL HEALTH IN SOUTHWESTERN PUERTO RICO". In GSA Annual Meeting in Denver, Colorado, USA - 2016. Geological Society of America, 2016. http://dx.doi.org/10.1130/abs/2016am-285089.

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"Contrasting sediment and nutrient export patterns across different hydrological regimes: A case study in the Great Barrier Reef catchments". In 25th International Congress on Modelling and Simulation. Modelling and Simulation Society of Australia and New Zealand, 2023. http://dx.doi.org/10.36334/modsim.2023.liu77.

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East, Amy, Andrew W. Stevens, Andrew C. Ritchie, Patrick L. Barnard, Pamela Campbell-Swarzenski, Brian D. Collins e Christopher H. Conaway. "LANDSCAPE RESPONSE TO HYDROCLIMATIC EXTREMES: A REGIME SHIFT IN SEDIMENT EXPORT FROM A COASTAL WATERSHED DURING A RECORD WET WINTER, CALIFORNIA". In GSA Annual Meeting in Indianapolis, Indiana, USA - 2018. Geological Society of America, 2018. http://dx.doi.org/10.1130/abs/2018am-316102.

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NAIRN, ROBERT B., MOHAMMAD DIBAJNIA, QIMIAO LU e DANIELLY DELPUPO. "LIQUEFACTION FLOW SLIDES AT VALE'S ORE EXPORT TERMINAL, BRAZIL". In Coastal Sediments 2015. WORLD SCIENTIFIC, 2015. http://dx.doi.org/10.1142/9789814689977_0123.

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Rapporti di organizzazioni sul tema "Sediment export":

Nittrouer, Charles A. Documenting Fine-Sediment Import and Export for Two Contrasting Mesotidal Flats. Fort Belvoir, VA: Defense Technical Information Center, settembre 2011. http://dx.doi.org/10.21236/ada557210.

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Miquel, J.-C., S. Fowler, T. Hamilton, J. Heilmann, J. LaRosa e M. Carroll. Carbon fluxes and export in the northern and middle Atlantic Sea measured with drifting sediment traps. Office of Scientific and Technical Information (OSTI), luglio 2000. http://dx.doi.org/10.2172/15005963.

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Nittrouer, Charles A. Documenting Fine-Sediment Import and Export for Two Contrasting Mesotidal Flats Sediment Flux through the Mekong Tidal River, Delta and Mangrove Shoreline Instrumentation to Support Investigation of Large Tropical Deltas. Fort Belvoir, VA: Defense Technical Information Center, settembre 2013. http://dx.doi.org/10.21236/ada598024.

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Zhang, Z., e M. Wu. Analysis of Riverine Sediment and Nutrient Exports in Missouri River Basin by Application of SWAT Model. Office of Scientific and Technical Information (OSTI), maggio 2014. http://dx.doi.org/10.2172/1132248.

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Bernau, Jeremiah A., Charles G. Oviatt, Donald L. Clark e Brenda B. Bowen. Sediment Logs Compiled From the Great Salt Lake Desert, Western Utah, With a Focus on the Bonneville Salt Flats Area. Utah Geological Survey, giugno 2023. http://dx.doi.org/10.34191/ofr-754.

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Abstract (sommario):

Sediment logs from exposures, excavations, cores, and wells are valuable records that can be used to interpret depositional records, aquifer extents, and geologic structures. Here we present sediment logs compiled from the Great Salt Lake Desert (GSLD) in western Utah with a specific focus on the Bonneville Salt Flats area. The logs are grouped into three categories (shallow, alluvial fan, and deep) that may be used to explore different aspects of GSLD deposition.

Adriaens, Peter, Sam Bentley, Frank Bohlen, Todd Bridges, John Davis, Tim Dekker, Rebecca Dickhut, Nicolas Fisher, Kevin Gardner e Andrea Leeson. SERDP and ESTCP Expert Panel Workshop on Research and Development Needs for the In Situ Management of Contaminated Sediments. Fort Belvoir, VA: Defense Technical Information Center, ottobre 2004. http://dx.doi.org/10.21236/ada478703.

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Fields, Rhonda, Damarys Acevedo-Acevedo, Burton Suedel, E. Bourne, Patrick Deliman, Carlos Ruiz, Jack Milazzo et al. Proceedings from the Basin Sediment Management for Unique Island Topography Workshop, Mayagüez, Puerto Rico. Engineer Research and Development Center (U.S.), ottobre 2023. http://dx.doi.org/10.21079/11681/47822.

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This report summarizes the Basin Sediment Management for Unique Island Topography Workshop hosted in-person and virtually at the University of Puerto Rico Mayagüez (UPRM) Department of Civil Engineering and Surveying, Mayagüez, Puerto Rico on 11 March 2022. The workshop was attended by approximately 80 federal, state, local, and academic organizations participants. It focused on Engineering With Nature® (EWN®), green infrastructure (GI) and low impact development (LID) opportunities for unique tropical island topography and included seven presentations from subject matter experts, a discussion on limitations and problems with prior projects, and two concurrent breakout sessions. Preworkshop activities included a field trip to multiple sites in the Añasco watershed conducted 09 March 2022, which served as a base case for the workshop. The field trip provided participants a unique perspective of the island’s topography and post 2017 Hurricane María issues and impacts. During the breakout sessions, participants identified new project opportunities for EWN®-GI and LID at two selected sites from the field trip. Each group developed alternatives for their chosen site and identified concepts that could turn into great opportunities for the surrounding communities and significantly benefit the state of practice in Puerto Rico’s unique tropical island topography.

Patin, Thomas R. Management of Bottom Sediments Containing Toxic Substances: Proceedings of the U.S./Japan Experts Meeting (9th) Held at Jacksonville, Florida on 17-19 October 1983. Fort Belvoir, VA: Defense Technical Information Center, marzo 1985. http://dx.doi.org/10.21236/ada157863.

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Rice, J. M., M. Ross, H E Campbell, R. C. Paulen e M. B. McClenaghan. Net evolution of subglacial sediment transport in the Quebec-Labrador Sector of the Laurentide Ice Sheet, Quebec and Newfoundland and Labrador. Natural Resources Canada/CMSS/Information Management, 2023. http://dx.doi.org/10.4095/332151.

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The interior of the Laurentide Ice Sheet (LIS) had a dynamic polythermal base. However, the subglacial thermal organization of the LIS and its evolution throughout glaciation are poorly constrained. Specifically, the net effect of ice divide migration on subglacial processes and the resulting landforms and sediments remains poorly understood. The results of a regional-scale till sampling program within the interior of the Quebec-Labrador sector of the LIS were used to explore dispersal patterns across a region known to have experienced ice divide migration. Indicator mineral and clast lithology analysis, coupled with multivariate analysis of the till matrix geochemistry, were used collectively, and evaluated within the context of the relative ice flow chronology and subglacial thermal evolution to augment our understanding of how ice divide migration impacts subglacial erosion and sedimentary processes. Indicator minerals (e.g., goethite and orthopyroxene) and clasts (e.g., iron formation clasts from the Labrador Trough) form glacial dispersal patterns that are consistent with the earliest northeast-trending ice-flow phase identified in the region. This early ice-flow phase produced and transported till across the entire study area (&gt; 175 km). However, till matrix geochemistry shows a strong relationship with the local underlying bedrock, especially the major oxides. This relationship is relatively common in areas of thin till cover and resistant bedrock lithologies. The results also indicate that following the northeast ice-flow phase, erosion and till production became more localized, without considerable transport in a single sustained direction. These results are consistent with a transition to more sporadic warm-based conditions and ice divide migration, as ice sheet reconstructions indicate, and are supported by targeted 10Be data from erratics and bedrock surfaces. There are also spatial relationships between the dispersal of fresh or re-entrained debris and paleo-ice streams identified in the landform record, as evidenced by the dispersal of indicator minerals. The reworking of previously dispersed material during subsequent ice-flow phases resulted in complex dispersal patterns across the study area. These results provide important insights for ice sheet modelling and future mineral exploration programs in inner ice sheet regions of the LIS and demonstrate the importance of a thorough understanding of ice-flow history.

Beck, Aaron. NAPTRAM - Plastiktransportmechanismen, Senken und Interaktionen mit Biota im Nordatlantik / NAPTRAM - North Atlantic plastic transport mechanisms, sinks, and interactions with biota, Cruise No. SO279, Emden (Germany) – Emden (Germany), 04.12.2020 – 05.01.2021. Gutachterpanel Forschungsschiffe Bonn, 2021. http://dx.doi.org/10.3289/cr_so279.

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The coastal and open oceans represent a major, but yet unconstrained, sink for plastics. It is likely that plastic-biota interactions are a key driver for the fragmentation, aggregation, and vertical transport of plastic litter from surface waters to sedimentary sinks. Cruise SO279 conducted sampling to address core questions of microplastic distribution in the open ocean water column, biota, and sediments. Seven stations were sampled between the outer Bay of Biscay and the primary working area south of the Azores. Additional samples were collected from surface waters along the cruise track to link European coastal and shelf waters with the open ocean gyre. Microplastic samples coupled with geochemical tracer analyses will build a mechanistic understanding of MP transport and its biological impact reaching from coastal seas to the central gyre water column and sinks at the seabed. Furthermore, floating plastics were sampled for microbial community and genetic analyses to investigate potential enzymatic degradation pathways. Cruise SO279 served as the third cruise of a number of connected research cruises to build an understanding of the transport pathways of plastic and microplastic debris in the North Atlantic from the input through rivers and air across coastal seas into the accumulation spots in the North Atlantic gyre and the vertical export to its sink at the seabed. The cruise was an international effort as part of the JPI Oceans project HOTMIC (“HOrizontal and vertical oceanic distribution, Transport, and impact of MICroplastics”) and the BMBF funded project PLASTISEA (‘Harvesting the marine Plastisphere for novel cleaning concepts’), and formed a joint effort of HOTMIC and PLASTISEA researchers from a range of countries and institutes.