Natural and anthropogenic drivers of denudation and sedimentary source-to-sink fluxes in the boreal mountain basin of lake Selbusjøen in central Norway

2021 ◽  
Author(s):  
Achim A. Beylich ◽  
Katja Laute
Keyword(s):  
Sediment Transport ◽  
Drainage Basin ◽  
Anthropogenic Activities ◽  
Field Work ◽  
Stream Channel ◽  
Surface Areas ◽  
Denudation Rates ◽  
Source To Sink ◽  
Sedimentary Source ◽  
Anthropogenic Drivers

<p>Denudation, including both chemical and mechanical processes, is of high relevance for landscape development and the transfer of solutes and sediments from headwater systems through main stem of drainage basin systems into sinks like lakes or the sea. Denudation is controlled by a range of environmental drivers and is in most environments and landscapes worldwide significantly affected by anthropogenic activities.</p><p>In the boreal mountain environment of central Norway the regulated lake Selbusjøen, situated at ca. 160 m a.s.l. with an area of 58 km<sup>2</sup> and connecting the upstream main mountain river Nea and the downstream main river Nidelva, forms a significant sink for sediments being transferred from its drainage basin area of in total 2876 km<sup>2</sup>.  The significant sediment trapping efficiency of lake Selbusjøen is causing a sediment deficit and locally increased fluvial erosion and down-cutting in the downstream river Nidelva which drains into the Trondheim fjord.</p><p>This ongoing GFL research on natural and anthropogenic drivers and the spatiotemporal variability of contemporary chemical and mechanical fluvial denudation rates and sedimentary source-to-sink fluxes in the boreal mountain basin of lake Selbusjøen is based on statistical analyses of high-resolution meteorological data, detailed field and remotely sensed mapping, computing of morphometric catchment parameters, and year-round process geomorphological field work. Geomorphological field work includes detailed field observations, repeated photographic documentations of selected stream channel stretches and slope surface areas, and field monitoring and frequent measurements with snow, rain water, stream-water and bedload samplings for the analysis of solute and suspended sediment concentrations and the study of atmospheric solute inputs, and the quantification of fluvial solute and sediment transport. Field work is carried out in 25 defined catchments/drainage areas draining into Selbusjøen. The selected catchment/drainage area systems are all characterized by large surface areas with a nearly closed and continuous vegetation cover mostly composed of boreal forests and bogs, and represent a range of different catchment sizes, catchment morphometries, orientations/aspects, and sediment sources and availabilities. In addition, different types and intensities of anthropogenic impact like, e.g., agriculture, forestry and modifications of natural stream channels (e.g., dams, steps, bank protection) and channel discharge for water power purposes are found in various catchments.</p><p>Runoff is occurring year-round and the natural runoff regime is clearly nival. Most fluvial transport is occurring during peak-runoff events generated by snowmelt, rainfall events or combinations of snowmelt and rainfall.  Altogether, chemical denudation is moderate but dominates clearly over mechanical fluvial denudation. Both chemical and mechanical fluvial denudation show a significant spatial variability which can be related to the varying characteristics of the selected catchment/drainage area systems. Agriculture and forestry are generally increasing mechanical fluvial denudation rates whereas anthropogenic stream channel and channel discharge modifications are leading to reduced fluvial bedload transport rates into lake Selbusjøen. Ongoing and accelerated climate change with the related changes of the current wind, temperature and precipitation regimes are expected to increase both chemical and mechanical fluvial denudation and sediment transport rates into lake Selbusjøen, particularly in the surface areas that have been modified by anthropogenic activities.</p>

Hydro-geochemical properties with respect to landuse in the southernmost river of Kerala

2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Badusha M. ◽  
Santhosh S
Keyword(s):  
Organic Carbon ◽  
Drainage Basin ◽  
Anthropogenic Activities ◽  
Oxygen Demand ◽  
Ion Concentration ◽  
Total Hardness ◽  
Hydrogen Ion Concentration ◽  
Geochemical Properties ◽  
Quality Of Water

The hydro geochemical features of Neyyar River for a period of one year from May 2015 to April 2016 were analyzed. Six sampling sites were fixed considering physiography and present landuse pattern of the river basin. The residents in the drainage basin are primarily responsible for framing a better landuse and thereby maintain a good water and sediment regime. Geospatial pattern of the present landuse of the study area indicated that the sustainability of this river ecosystem is in danger due to unscientific landuse practices, which is reflected in the river quality as well. The parameters such as hydrogen ion concentration, electrical conductivity, chloride, Biological Oxygen Demand, total hardness and sulphate of river water and Organic Carbon of river bed sediments were analyzed in this study. The overall analysis shows that the highland areas are characterized by better quality of water together with low organic carbon, which is mainly due to better landuse and minimal reclamation. The midland and lowland areas are characterized by poor quality of water with high organic carbon, which is due to high anthropogenic activities and maximum pollutants associated with the region together with the alteration in landuse from a traditional eco-friendly pattern to a severely polluted current pattern.

Chemical Composition and Metal Speciation in Porewaters from the Upper Qu’Appelle River Basin, Saskatchewan

1993 ◽  
Vol 28 (1) ◽  
pp. 83-110 ◽  
Author(s):  
Richard E. Farrell ◽  
Jae E. Yang ◽  
P. Ming Huang ◽  
Wen K. Liaw
Keyword(s):  
Amino Acids ◽  
Trace Metal ◽  
River Basin ◽  
Drainage Basin ◽  
Metal Speciation ◽  
Anthropogenic Activities ◽  
High Concentration ◽  
Metal Concentrations ◽  
Carbonate Equilibria ◽  
The Impact

Abstract Porewater samples from the upper Qu’Appelle River basin in Saskatchewan, Canada, were analyzed to obtain metal, inorganic ligand and amino add profiles. These data were used to compute the aqueous speciation of the metals in each porewater using the computer program GEOCHEM-PC. The porewaters were classified as slightly to moderately saline. Metal concentrations reflected both the geology of the drainage basin and the impact of anthropogenic activities. Whereas K and Na were present almost entirely as the free aquo ions, carbonate equilibria dominated the speciation of Ca. Mg and Mn (the predominant metal ligand species were of the type MCO3 (s). MCO30. and MHCO3+). Trace metal concentrations were generally within the ranges reported for non-polluted freshwater systems. Whereas the speciation of the trace metals Cr(III) and Co(II) was dominated by carbonate equilibria, Hg(II)-, Zn(II)- and Fe(II)-speciation was dominated by hydroxy-metal complexes of the type M(OH)+ and M(OH)2°. The speciation of Fe(III) was dominated by Fe(OH)3 (s). In porewaters with high chloride concentrations (> 2 mM), however, significant amounts of Hg(II) were bound as HgCl20 and HgClOH0. The aqueous speciation of Al was dominated by Al(OH)4− and Al2Si2O4(OH)6 (s). Total concentrations of dissolved free amino acids varied from 15.21 to 25.17 umole L−1. The most important metal scavenging amino acids were histidine (due to high stability constants for the metal-histidine complexes) and tryptophan (due to its relatively high concentration in the porewaters. i.e., 5.96 to 7.73 umole L−1). Secondary concentrations of various trace metal-amino add complexes were computed for all the porewaters, but metal-amino acid complexes dominated the speciation of Cu(II) in all the porewaters and Ni(II) in two of the porewaters.

scholarly journals Coastal Flooding and Erosion under a Changing Climate: Implications at a Low-Lying Coast (Ebro Delta)

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 346 ◽  
Author(s):  
Albert Grases ◽  
Vicente Gracia ◽  
Manuel García-León ◽  
Jue Lin-Ye ◽  
Joan Pau Sierra
Keyword(s):  
Climate Change ◽  
Sediment Transport ◽  
Sea Level ◽  
Anthropogenic Activities ◽  
Management Strategies ◽  
Wave Model ◽  
Ebro Delta ◽  
Coastal Hazards ◽  
Sand Transport ◽  
Storm Waves

Episodic coastal hazards associated to sea storms are responsible for sudden and intense changes in coastal morphology. Climate change and local anthropogenic activities such as river regulation and urban growth are raising risk levels in coastal hotspots, like low-lying areas of river deltas. This urges to revise present management strategies to guarantee their future sustainability, demanding a detailed diagnostic of the hazard evolution. In this paper, flooding and erosion under current and future conditions have been assessed at local scale at the urban area of Riumar, a touristic enclave placed at the Ebro Delta (Spain). Process-based models have been used to address the interaction between beach morphology and storm waves, as well as the influence of coastal environment complexity. Storm waves have been propagated with SWAN wave model and have provided the forcings for XBeach, a 2DH hydro-morphodynamic model. Results show that future trends in sea level rise and wave forcing produce non-linear variations of the flooded area and the volume of mobilized sediment resulting from marine storms. In particular, the balance between flooding and sediment transport will shift depending on the relative sea level. Wave induced flooding and long-shore sand transport seem to be diminished in the future, whereas static sea level flooding and cross-shore sediment transport are exacerbated. Therefore, the characterization of tipping points in the coastal response can help to develop robust and adaptive plans to manage climate change impact in sandy wave dominated coasts with a low-lying hinterland and a complex shoreline morphology.

scholarly journals Theoretical Interpretation of the Exceptional Sediment Transport of Fine-grained Dispersal Systems Associated with Bedform Categories

2018 ◽  
Author(s):  
Tian Zhao ◽  
Qian Yu ◽  
Yunwei Wang ◽  
Shu Gao
Keyword(s):  
Sediment Transport ◽  
Regime Shift ◽  
Sedimentary Environment ◽  
Sediment Flux ◽  
Theoretical Interpretation ◽  
Fine Grained ◽  
Transport Regime ◽  
Source To Sink ◽  
Bed Roughness ◽  
Set Up

Abstract. Being a widespread source-to-sink sedimentary environment, the fine-grained dispersal system (FGDS) features remarkably high sediment flux, interacting closely with local morphology and ecosystem. Such exceptional transport is believed to be associated with changes in bedform geometry, which further demands theoretical interpretation. Using van Rijn (2007a) bed roughness predictor, we set up a simple numerical model to calculate sediment transport, classify sediment transport behaviors into dune and (mega-)ripple dominant regimes, and discuss the causes of the sediment transport regime shift linked with bedform categories. Both regimes show internally consistent transport behaviors, and the latter, associated with FGDSs, exhibits considerably higher sediment transport rate than the previous. Between lies the coexistence zone, the sediment transport regime shift accompanied by degeneration of dune roughness, which can considerably reinforce sediment transport and is further highlighted under greater water depth. This study can be applied to modeling of sediment transport and morphodynamics.

scholarly journals Examining the provenance of branched GDGTs in the Tagus River drainage basin and its outflow into the Atlantic Ocean over the Holocene to determine their usefulness for paleoclimate applications

2016 ◽  
Vol 13 (20) ◽  
pp. 5719-5738 ◽  
Author(s):  
Lisa Warden ◽  
Jung-Hyun Kim ◽  
Claudia Zell ◽  
Geert-Jan Vis ◽  
Henko de Stigter ◽  
...  
Keyword(s):  
Iberian Peninsula ◽  
Marine Sediments ◽  
Arid Regions ◽  
Drainage Basin ◽  
Deep Ocean ◽  
Climate Reconstructions ◽  
Source To Sink ◽  
Tagus River ◽  
Global Soil ◽  
Paleoclimate Reconstructions

Abstract. The distributions of branched glycerol dialkyl glycerol tetraethers (brGDGTs), which are transported from the soils where they are predominantly produced to marine sediments via rivers, have been applied in reconstructing mean annual air temperature (MAT) and pH of soils. However, paleoclimate reconstructions using sedimentary brGDGTs have proven difficult in arid regions, including the Iberian Peninsula. Recently, six novel 6-methyl brGDGTs have been described using new analytical methods (in addition to the nine 5-methyl brGDGTs previously used for climate reconstructions), and so new pH and MAT calibrations have been developed that were shown to improve the accuracy of reconstructions in a set of global soil samples, especially in arid regions. Because of this we decided to apply the new method to separate the 5- and 6-methyl isomers along with the novel calibrations to a sample set from the Iberian Peninsula to determine whether it improves paleoclimate reconstructions in this area. This set includes samples that run in a transect from source to sink along the Tagus River and out to the deep ocean off the Portuguese margin spanning the last 6000 years. We found that although pH reconstructions in the soils were improved using the new calibration, MAT reconstructions were not much better even with the separation of the 5- and 6-methyl brGDGTs. This confirmed the conclusion of previous studies that the amount of aquatically produced brGDGTs is overwhelming the soil-derived ones in marine sediments and complicating MAT reconstructions in the region. Additionally, the new separation revealed a strong and until now unseen relationship between the new degree of cyclization (DC') of the brGDGTs and MAT that could be making temperature reconstructions in this and other arid regions difficult.

Aquatic pollution: effects on the health of fish and shellfish

Parasitology ◽  
1993 ◽  
Vol 106 (S1) ◽  
pp. S25-S37 ◽  
Author(s):  
D. Bucke
Keyword(s):  
North Sea ◽  
Anthropogenic Activities ◽  
Field Work ◽  
Demersal Fish ◽  
Conclusive Evidence ◽  
Inland Waters ◽  
Pollution Effects ◽  
Liver Tumours ◽  
The Past ◽  
Fish And Shellfish

SUMMARYAs there is little evidence of pollution affecting the health of fish and shellfish on a global scale, this paper attempts to put into perspective the pollution/fish disease relationship by reviewing examples of studies and reports in the historic and current literature. Although there is no dispute that pollution can affect the health of aquatic organisms under laboratory conditions and may be responsible for the decline of populations of such animals in some inland waters and some estuaries, most of the evidence for pollution causing or increasing disease in fish in open waters is circumstantial. Historical data proves that almost all fish and shellfish diseases known today have been described since the end of the last century. However, it is also known that water pollution, especially in inland waters, has for the past 400-500 years been the result of urbanization and industrialization. This has resulted in some major rivers becoming devoid of or deficient in fish stocks. The concern that pollution may influence the health status of fish and shellfish stocks has increased over the past 20 years. Initial attention was paid to epidermal diseases, including fin-rot in demersal fish, and protozoan diseases in molluscs in the heavily polluted bays and estuaries in North America. As the interest in this subject spread, it became political, and often controversial, especially amongst the North Sea countries. The disagreements have largely been settled amongst scientists because international bodies, such as the International Council for Exploration of the Sea (ICES), established workshops to investigate sampling methods and disease-reporting techniques. Recommendations from those workshops have contributed to some form of standardization for field work and the subject, although largely subjective, has some objective approaches which are described. As there are variable, interacting biological and physical influences in the aquatic environment, it is difficult to establish the background prevalences of diseases in populations offish and shellfish. Examples of the influences of climatic changes are presented, and these show that short-term catastrophes can be directly related. However, a more long-term problem is water acidification resulting largely from anthropogenic activities. In parts of Scandinavia this has, and is, leading to decimation offish stocks in inland waters. In general, diseases in fish and shellfish are very localized, but there is concern amongst scientists that certain cancers, especially liver tumours, occurring in demersal fish inhabiting polluted estuarine and coastal waters, are related to the release of chemicals, e.g. hydrocarbons, pesticides and heavy metals. This subject is discussed in detail, with examples of the author's own studies in North Sea fish. It is concluded that cancers in fish are of extremely low prevalence, and only present in a very few species, and then only in the oldest animals. Though changes in disease pattern may well be an indication of adverse environmental effects, further research is necessary for conclusive evidence.

scholarly journals Soilscape evolution of aeolian-dominated hillslopes during the Holocene: investigation of sediment transport mechanisms and climatic–anthropogenic drivers

2017 ◽  
Vol 5 (1) ◽  
pp. 101-112 ◽  
Author(s):  
Sagy Cohen ◽  
Tal Svoray ◽  
Shai Sela ◽  
Greg Hancock ◽  
Garry Willgoose
Keyword(s):  
Sediment Transport ◽  
Considerable Effect ◽  
Environmental Drivers ◽  
Diffusive Transport ◽  
Transport Mechanisms ◽  
Field Site ◽  
Soil Features ◽  
Climatic Anthropogenic ◽  
Soil Distribution ◽  
Anthropogenic Drivers

Abstract. Here we study the soilscape (soil-landscape) evolution of a field site in the semiarid zone of Israel. This region, like similar regions around the world, was subject to intensive loess accumulation during the Pleistocene and early Holocene. Today, hillslopes in this region are dominated by exposed bedrock with deep loess depositions in the valleys and floodplains. The drivers and mechanism that led to this soilscape are unclear. Within this context, we use a soilscape evolution model (mARM5D) to study the potential mechanisms that led to this soilscape. We focus on advancing our conceptual understanding of the processes at the core of this soilscape evolution by studying the effects of fluvial and diffusive sediment transport mechanisms, and the potential effects of climatic and anthropogenic drivers. Our results show that, in our field site, dominated by aeolian soil development, hillslope fluvial sediment transport (e.g., surface wash and gullies) led to downslope thinning in soil, while diffusive transport (e.g., soil creep) led to deeper and more localized soil features at the lower sections of the hillslopes. The results suggest that, in this semiarid, aeolian-dominated and soil-depleted landscape, the top section of the hillslopes is dominated by diffusive transport and the bottom by fluvial transport. Temporal variability in environmental drivers had a considerable effect on soilscape evolution. Short but intensive changes during the late Holocene, imitating anthropogenic land use alterations, rapidly changed the site's soil distribution. This leads us to assume that this region's soil-depleted hillslopes are, at least in part, the result of anthropogenic drivers.

Geomorphic and hydrologic consequences of vegetation destruction, Sudbury, Ontario

1976 ◽  
Vol 13 (10) ◽  
pp. 1358-1373 ◽  
Author(s):  
Andrew J. Pearce
Keyword(s):  
Flood Control ◽  
Overland Flow ◽  
Drainage Basin ◽  
Weighted Average ◽  
Design Parameters ◽  
Snowmelt Runoff ◽  
Control Structures ◽  
Denudation Rates ◽  
Complete Destruction ◽  
Erosion Pins

Near-complete destruction of vegetation over 125 km2 near Sudbury, Ontario has increased denudation rates by two orders of magnitude and caused substantial changes in hydrologic regime. Denudation by channeled and unchanneled flow, measured with erosion pins on small plots (2–1000 m2) and a small drainage basin (0.09 km2), averaged 6000 m3/km2 (maximum 24 700 m3/km2) during summer and fall in 1971 and 1972. Maximum denudation occurred during late August to October. Snowmelt runoff in 1972 yielded 1000 m3/km2 of sediment. The weighted average denudation rate, including rates of bedrock disintegration (60–170 m3/km2/y; mean 120 m3/km2/y) is 3700 m3/km2/y.Runoff coefficients average 0.88 for events with return periods between 2 and 10 years; 25% of the May–October rainfall runs off as Hortonian overland flow. Estimated sedimentation rates for three flood-control structures indicate 25% storage depletion over a 50 year period; the return period of floods then able to be retained is reduced to 50 years, compared to the design parameters of 100 year 6 h rainfall (smaller structures) and 100–200 year 12 h rainfall, 6 h P.M.P. (largest structure).

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