scholarly journals Organic matter dynamics and stable isotope signature as tracers of the sources of suspended sediment

2012 ◽  
Vol 9 (6) ◽  
pp. 1985-1996 ◽  
Author(s):  
Y. Schindler Wildhaber ◽  
R. Liechti ◽  
C. Alewell
Keyword(s):  
Organic Matter ◽  
Suspended Sediment ◽  
Brown Trout ◽  
Arable Land ◽  
Atomic Ratio ◽  
High Flow ◽  
Low Flow ◽  
Organic C ◽  
Sediment Loads ◽  
Temporal And Spatial

Abstract. Suspended sediment (SS) and organic matter in rivers can harm brown trout Salmo trutta by affecting the health and fitness of free swimming fish and by causing siltation of the riverbed. The temporal and spatial dynamics of sediment, carbon (C), and nitrogen (N) during the brown trout spawning season in a small river of the Swiss Plateau were assessed and C isotopes as well as the C/N atomic ratio were used to distinguish autochthonous and allochthonous sources of organic matter in SS loads. The visual basic program IsoSource with 13Ctot and 15N as input isotopes was used to quantify the temporal and spatial sources of SS. Organic matter concentrations in the infiltrated and suspended sediment were highest during low flow periods with small sediment loads and lowest during high flow periods with high sediment loads. Peak values in nitrate and dissolved organic C were measured during high flow and high rainfall, probably due to leaching from pasture and arable land. The organic matter was of allochthonous sources as indicated by the C/N atomic ratio and δ13Corg. Organic matter in SS increased from up- to downstream due to an increase of pasture and arable land downstream of the river. The mean fraction of SS originating from upper watershed riverbed sediment decreased from up to downstream and increased during high flow at all measuring sites along the course of the river. During base flow conditions, the major sources of SS are pasture, forest and arable land. The latter increased during rainy and warmer winter periods, most likely because both triggered snow melt and thus erosion. The measured increase in DOC and nitrate concentrations during high flow support these modeling results. Enhanced soil erosion processes on pasture and arable land are expected with increasing heavy rain events and less snow during winter seasons due to climate change. Consequently, SS and organic matter in the river will increase, which will possibly affect brown trout negatively.

scholarly journals Organic matter dynamics and stable isotopes for tracing sources of suspended sediment

2012 ◽  
Vol 9 (1) ◽  
pp. 453-483 ◽  
Author(s):  
Y. Schindler Wildhaber ◽  
R. Liechti ◽  
C. Alewell
Keyword(s):  
Organic Matter ◽  
Suspended Sediment ◽  
Brown Trout ◽  
Arable Land ◽  
Atomic Ratio ◽  
High Flow ◽  
Low Flow ◽  
Organic C ◽  
Erosion Processes ◽  
Sediment Loads

Abstract. Suspended sediment (SS) and organic matter in rivers can harm brown trout Salmo trutta by impact on health and fitness of free swimming fish and siltation of the riverbed. The later results in a decrease of hydraulic conductivity and therefore smaller oxygen supply to the salmonid embryos. Additionally, oxygen demand within riverbeds will increase as the pool of organic matter increases. We assessed the temporal and spatial dynamics of sediment, carbon (C) and nitrogen (N) during the brown trout spawning season and used C isotopes as well as the C/N atomic ratio to distinguish autochthonous and allochthonous sources of organic matter in SS loads. The visual basic program IsoSource with 13Ctot and 15N as input isotopes was used to quantify the sources of SS in respect of time and space. Organic matter fractions in the infiltrated and suspended sediment were highest during low flow periods with small sediment loads and lowest during high flow periods with high sediment loads. Peak values in nitrate and dissolved organic C were measured during high flow and precipitation probably due to leaching from pasture and arable land. The organic matter was of allochthonous sources as indicated by the C/N atomic ratio and δ13Corg. Organic matter in SS increased from up- to downstream due to pasture and arable land. The fraction of SS originating from upper watershed riverbed sediment increased at all sites during high flow. Its mean fraction decreased from up- to downstream. During base flow conditions, the major sources of SS are pasture and arable land. The later increased during rainy and warmer periods probably due to snow melting and erosion processes. These modeling results support the measured increased DOC and NO3 concentrations during high flow.

scholarly journals Diagenetic control of nitrogen isotope ratios in Holocene sapropels and recent sediments from the Eastern Mediterranean Sea

2010 ◽  
Vol 7 (1) ◽  
pp. 1131-1165 ◽  
Author(s):  
J. Möbius ◽  
N. Lahajnar ◽  
K.-C. Emeis
Keyword(s):  
Organic Matter ◽  
Primary Production ◽  
Surface Sediments ◽  
Eastern Mediterranean ◽  
Nitrogen Isotope ◽  
Organic C ◽  
Deep Waters ◽  
Spatially Distributed ◽  
Temporal And Spatial ◽  
Recent Sediments

Abstract. The enhanced accumulation of organic matter in Eastern Mediterranean sapropels and their unusually depleted δ15N values have been attributed to either enhanced nutrient availability which led to elevated primary production and carbon sequestration or to enhanced organic matter preservation under anoxic conditions. In order to evaluate these two hypothesis we have determined Ba/Al ratios, amino acid composition, N and organic C concentrations and δ15N on sinking particles, surface sediments, eight spatially distributed core records of the youngest sapropel S1 (10-6 ka) and older sapropels (S5, S6) from two locations. These data suggest that (i) temporal and spatial variations in δ15N of sedimentary N are driven by different degrees of diagenesis at different sites rather than by changes in N-sources or primary productivity and (ii) that present day TOC export production would suffice to create a sapropel like S1 under conditions of deep-water anoxia. This implies that both enhanced TOC accumulation and δ15N depletion in sapropels were due to the absence of oxygen in deep waters. Thus preservation plays a major role for the accumulation of organic-rich sediments casting doubt the need of enhanced primary production for sapropel formation.

Fluvial Sedimentation in Southern Ontario

1975 ◽  
Vol 12 (11) ◽  
pp. 1813-1819 ◽  
Author(s):  
W. T. Dickinson ◽  
A. Scott ◽  
G. Wall
Keyword(s):  
Suspended Sediment ◽  
Drainage Density ◽  
Low Flow ◽  
Southern Ontario ◽  
Frequency Distributions ◽  
Sediment Yields ◽  
Sediment Loads ◽  
Fluvial Sedimentation ◽  
Sediment Data ◽  
Suspended Loads

Suspended sediment data for Southern Ontario stream have been analyzed with regard to areal and temporal patterns, characteristics of sediment concentrations, and relationships between sediment loads and watershed parameters. The range of annual suspended sediment yields for seven river basins is determined as 5250 to 175 000 kg/year/km2. The daily suspended loads exhibit highly skewed frequency distributions, with mean loads being equalled or exceeded less than 20% of the time and 50% of the annual load occurring during the months of March and April. It is demonstrated that sample loads collected during periods of low flow, and stream rankings determined from low flow data, are not indicative of the annual suspended sediment load picture. No simple model between suspended loads and such basin indices as relief ratio and drainage density is found to be satisfactory for prediction purposes.

scholarly journals Scale breaks of suspended sediment rating in large rivers in Germany induced by organic matter

2020 ◽  
Vol 8 (3) ◽  
pp. 661-678
Author(s):  
Thomas O. Hoffmann ◽  
Yannik Baulig ◽  
Helmut Fischer ◽  
Jan Blöthe
Keyword(s):  
Organic Matter ◽  
Suspended Sediment ◽  
Suspended Matter ◽  
Monitoring Network ◽  
Suspended Sediments ◽  
Low Flow ◽  
Rating Curve ◽  
Organic Fraction ◽  
Sediment Rating Curve ◽  
Aquatic Biomass

Abstract. Understanding the transport of suspended sediment and associated nutrients is of major relevance for sustainable sediment management aiming to achieve healthy river systems. Sediment rating curves are frequently used to analyze the suspended sediments and their potential sources and sinks. Here we use more than 750 000 measurements of suspended sediment concentrations (SSCs) and discharge (Q) collected at 62 gauging stations along 19 waterways in Germany based on the suspended sediment monitoring network of the German water and shipping authority, which started in the 1960s. Furthermore, we analyze more than 2000 measurements of the loss on ignition (LOI) of suspended matter at two stations along the rivers Moselle and Rhine to provide a proxy for the relative contributions of mineral load and organic matter. SSC and LOI are analyzed in terms of the power-law rating curve to identify discharge-dependent controls of suspended matter. Our results indicate that for most studied gauging stations, rating coefficients are not constant over the full discharge range, but there is a distinct break in the sediment rating curve, with specific SSC–Q domains above and below this break. The transition of the rating exponent likely results from increased supply of mineral suspended sediments from hillslope erosion at high flow and a shift of the organic matter sources from aquatic biomass-derived organic matter (i.e., high % LOI) at low flow, to mineral-associated organic matter with low % LOI eroded from hillslopes at higher flow. Based on these findings we developed a conceptual rating model for large (>10 000 km2) and low-turbidity (SSC < 1000 mg L−1) rivers separating the mineral and organic fraction of the suspended matter in German waterways. This model allows evaluating the sources of the mineral and organic fraction of the suspended matter and facilitates new insights into the first-order control of discharge on the quality and quantity of suspended sediments.

scholarly journals Long – term evalutation of the organic matter balance and its relations to the organic C content in the topsoils in Ústí nad Orlicí district

2009 ◽  
Vol 57 (2) ◽  
pp. 13-24 ◽  
Author(s):  
Jiří Dostál ◽  
Dana Cerhanová ◽  
Lenka Hajzlerová ◽  
Jana Martincová ◽  
Petra Pospíšilová ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Farmyard Manure ◽  
Arable Land ◽  
Water Soluble ◽  
Hot Water ◽  
Hydrophobicity Index ◽  
Organic C ◽  
Time Period ◽  
Organic Fertilisers

Organic matter balance in the farms located in Ústí nad Orlicí district has been investigated since 1979. As a result, so called need of organic fertilisation, has been determined and the supply of the organic fertilisers to soils, e.g. farmyard manure, slurries and also straw and green manure has been monitored over the whole time period. About 45 % of the arable land area in the district has been monitored.In addition to the organic matter balance, we determined several soil organic matter characteristics in soil samples (organic C, N and S contents, inert and decomposable C content, hot water soluble C content, hydrophobicity index calculated from the DRIFT spectrometry, available P, K, Ca and Mg contents and pH).The relationships between the organic matter supply with supplemental sources organic fertilisers and all the selected soil organic matter characteristics were statistically significant. Significant correlations were also found for the relationships between the organic matter need and all the selected soil organic matter characteristics.

scholarly journals Along-stream transport and transformation of dissolved organic matter in a large tropical river

2016 ◽  
Author(s):  
Thibault Lambert ◽  
Cristian R. Teodoru ◽  
Frank C. Nyoni ◽  
Steven Bouillon ◽  
François Darchambeau ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Water Discharge ◽  
Large River ◽  
High Flow ◽  
Low Flow ◽  
River Continuum ◽  
Fluorescence Measurements ◽  
Tropical Areas ◽  
Stream Transport

Abstract. Large rivers transport considerable amounts of terrestrial dissolved organic matter (DOM) to the ocean. Yet, downstream gradients and temporal variability in DOM fluxes and characteristics are poorly studied at the scale of large river basins, especially in tropical areas. Here, we report longitudinal patterns in DOM content and composition based on absorbanc e and fluorescence measurements along the Zambezi River and its main tributary, the Kafue River, during two hydrological seasons. During high flow periods, a greater proportion of aromatic and humic DOM was mobilized along rivers due to the hydrological connectivity with wetlands and high flow velocities, while low flow periods were characterized by lower DOM content of less aromaticity resulting from loss of connectivity with wetlands, more efficient degradation of terrestrial DOM and enhanced autochthonous productivity. Changes in water residence time due to contrasting water discharge were found to modulate the fate of DOM along the river continuum. Thus, terrestrial DOM dynamics shifted from transport-dominated during the wet seasons towards degradation during the dry season, with substantial consequences on longitudinal DOM content and composition. The longitudinal evolution of DOM was also strongly impacted by a hydrological buffering effect in large reservoirs in which the seasonal variability of DOM fluxes and composition was strongly reduced.

scholarly journals Sediment sources in the Upper Severn catchment: a fingerprinting approach

1997 ◽  
Vol 1 (3) ◽  
pp. 509-521 ◽  
Author(s):  
A. L. Collins ◽  
D. E. Walling ◽  
G. J. L. Leeks
Keyword(s):  
Suspended Sediment ◽  
Base Cation ◽  
Mixing Model ◽  
Sediment Provenance ◽  
Sediment Sources ◽  
Surface Soils ◽  
Model Composite ◽  
Organic C ◽  
Commercial Activities ◽  
Sediment Loads

Abstract. Suspended sediment sources in the Upper Severn catchment are quantified using a composite fingerprinting technique combining statistically-verified signatures with a multivariate mixing model. Composite fingerprints are developed from a suite of diagnostic properties comprising trace metal (Fe, Mn, AI), heavy metal (Cu, Zn, Pb, Cr, Co, Ni), base cation (Na, Mg, Ca, K), organic (C, N), radiometric (137Cs, 210Pb), and other (total P) determinands. A numerical mixing model, to compare the fingerprints of contemporary catchment source materials with those of fluvial suspended sediment in transit and those of recent overbank floodplain deposits, provides a means of quantifying present and past sediment sources respectively. Sources are classified in terms of eroding surface soils under different land uses and channel banks. Eroding surface soils are the most important source of the contemporary suspended sediment loads sampled at the Institute of Hydrology flow gauging stations at Plynlimon and at Abermule. The erosion of forest soils, associated with the autumn and winter commercial activities of the Forestry Commission, is particularly evident. Reconstruction of sediment provenance over the recent past using a sediment core from the active river floodpiain at Abermule, in conjunction with a 137Cs chronology, demonstrates the significance of recent phases of afforestation and deforestation for accelerated catchment soil erosion.

scholarly journals Diagenetic control of nitrogen isotope ratios in Holocene sapropels and recent sediments from the Eastern Mediterranean Sea

2010 ◽  
Vol 7 (11) ◽  
pp. 3901-3914 ◽  
Author(s):  
J. Möbius ◽  
N. Lahajnar ◽  
K.-C. Emeis
Keyword(s):  
Organic Matter ◽  
Primary Production ◽  
Surface Sediments ◽  
Eastern Mediterranean ◽  
Nitrogen Isotope ◽  
Organic C ◽  
Deep Waters ◽  
Spatially Distributed ◽  
Temporal And Spatial ◽  
Recent Sediments

Abstract. The enhanced accumulation of organic matter in Eastern Mediterranean sapropels and their unusually low δ15N values have been attributed to either enhanced nutrient availability which led to elevated primary production and carbon sequestration or to enhanced organic matter preservation under anoxic conditions. In order to evaluate these two hypothesis we have determined Ba/Al ratios, amino acid composition, N and organic C concentrations and δ15N in sinking particles, surface sediments, eight spatially distributed core records of the youngest sapropel S1 (10–6 ka) and older sapropels (S5, S6) from two locations. These data suggest that (i) temporal and spatial variations in δ15N of sedimentary N are driven by different degrees of diagenesis at different sites rather than by changes in N-sources or primary productivity and (ii) present day TOC export production would suffice to create a sapropel like S1 under conditions of deep-water anoxia. This implies that both enhanced TOC accumulation and δ15N depletion in sapropels were due to the absence of oxygen in deep waters. Thus preservation plays a major role for the accumulation of organic-rich sediments casting doubt on the need of enhanced primary production for sapropel formation.

Researches on Temporal and Spatial Changes of Suspended Sediment Nutrients and Source Contributions in Xitiaoxi River, China

2014 ◽  
Vol 955-959 ◽  
pp. 3259-3265
Author(s):  
Zhao Peng Lu ◽  
Xu Yin Yuan ◽  
Hai Long Chen ◽  
Huan Wang ◽  
Xue Qiang Zhao
Keyword(s):  
Land Use ◽  
Suspended Sediment ◽  
Arable Land ◽  
Urban Land ◽  
Dry Season ◽  
Wet Season ◽  
Material Source ◽  
Sediment Nutrients ◽  
Geochemical Parameters ◽  
Temporal And Spatial

Xitiaoxi River is the main discharge river of Taihu Lake. It is important to research changes of suspended sediment nutrients and their provenances for the water environment management. This paper analyzes temporal and spatial variations of nutrients in suspended sediments (SS) and establishes the geochemical model to quantify the proportions of SS sources with geochemical parameters in different reaches. The results show that the contents of SS and its nutrients of the downstream are significantly higher than the upstream and midstream. The contents of nutrients in SS in dry season are higher than in wet season. The C/N and IP/OP ratios of SS can effectively reflect the material source types in the different reaches, which are associated with land use types. Woodland is relatively higher contribution to SS in the upstream, arable lands become a major contributor to SS in the midstream, while urban land is the highest contribution to SS in the downstream. Seasonal changes also affect the contributions of land use to SS. Woodland and urban land show more contributions to SS in wet season than in dry season, whereas arable land and bank sediment show the higher proportions for SS source.

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