Mountains and Montane Channels

Church, Michael

doi:10.1002/9780470682876.ch2

Cited by 19 publications

(15 citation statements)

References 92 publications

(110 reference statements)

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“…As a consequence, the increased erosion rates can elevate the sediment delivery from catchments [88] and lakes and reservoirs act as primary sink in the sediment cascade [89]. Increases of sedimentation rate have been observed in many European lakes over the last 100 years, in particular during 1950-1975 period and post-1975.…”

Section: Potential Effects Of Climate Change On Sediment Quality In Rmentioning

confidence: 99%

Climate Change Impacts on Sediment Quality of Subalpine Reservoirs: Implications on Management

Marziali¹,

Tartari²,

Salerno³

et al. 2017

Preprint

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Abstract:Reservoirs are characterized by accumulation of sediments where micropollutants may concentrate, with potential toxic effects on downstream river ecosystems. However, sediment management such as flushing is needed to maintain storage capacity. Climate change is expected to increase sediment loads, but potential effects on their quality are scarcely known. In this context, sediment contamination by trace elements (As, Cd, Cr, Cu, Hg, Ni, Pb, Zn) and organics (PAHs, PCBs, C>12) was analyzed in 20 reservoirs located in Italian Central Alps. A strong As and a moderate Cd, Hg and Pb enrichment was emphasized by Igeo, with potential ecotoxicological risk according to PEC quotients. Sedimentation rate, granulometry, total organic carbon (TOC) and altitude resulted as the main drivers governing pollutant concentrations in sediments. According to climate change models, expected increase of rainfall erosivity will enhance soil erosion and consequently the sediment flow to reservoirs, potentially increasing coarse grain fractions and thus potentially diluting pollutants. Conversely, increased weathering may enhance metal fluxes to reservoirs. Increased vegetation cover will potentially result in higher TOC concentrations, which may contrast contaminant bioavailability and thus toxicity. Our results may provide elements for a proper management of contaminated sediments in a climate change scenario aiming at preserving water quality and ecosystem functioning.

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Section: Potential Effects Of Climate Change On Sediment Quality In Rmentioning

confidence: 99%

Climate Change Impacts on Sediment Quality of Subalpine Reservoirs: Implications on Management

Marziali¹,

Tartari²,

Salerno³

et al. 2017

Preprint

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“…Additionally, the experiments showed that the importance of the minimum slope threshold by far outweighs that of the maximum distance threshold, hence we set the latter to infinity. Different thresholds have been suggested for the minimum channel gradient above which bedload transport is maintained: Church (2010) states that, if sediment size is the only criterion, no deposition occurs above a channel gradient of c. 4°, Wichmann (2006) applies a threshold of 3.5°. Here we use a threshold of 2° (Fryirs et al, 2007a, also use this threshold, but it is applied to delineate connectivity across the landscape, not specifically along the channel network) to account for discharge events of higher magnitude which are capable of moving coarse sediments from time to time.…”

Section: Slope Wash and Fluvial Bedload Transportmentioning

confidence: 99%

Geomorphic coupling and sediment connectivity in an alpine catchment — Exploring sediment cascades using graph theory

2013

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“…The general behavior of bed load transport and water discharge in the two streams for the 6 years of observations can be characterized by a two‐phase regime (Church, ; Warburton, ). At smaller water discharges, there is no clear dependence of bed load transport intensity ( IMP or Q b ) on water discharge ( Q ), whereas above a certain threshold water discharge Q c there is a steep increase of IMP or Q b with increasing Q (Figure and supporting information Figures S3 and S4).…”

Section: Resultsmentioning

confidence: 99%

Variability of Bed Load Transport During Six Summers of Continuous Measurements in Two Austrian Mountain Streams (Fischbach and Ruetz)

Rickenmann

2018

Water Resources Research

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Previous measurements of bed load transport in gravel bed streams revealed a large temporal and spatial variability of bed load transport rates. Using an impact plate geophone system, continuous bed load transport measurements were made during 6 years in two mountain streams in Austria. The two streams have a snow‐melt and glacier‐melt dominated hydrologic regime resulting in frequent transport activity during the summer half year. Periods of days to weeks were identified which are associated with approximately constant Shields values that indicate quasi‐stable bed conditions. Between these stable periods, the position of the bed load transport function varied while its steepness remained approximately constant. For integration time scales of several hours to 1 day, the fluctuations in bed load transport decreased and the correlation between bed load transport and water discharge increased. For integration times of about 70–100 days, bed load transport is determined by discharge or shear stress to within a factor of about 2, relative to the 6 year mean level. Bed load texture increased with increasing mean flow strength and mean transport intensity. Weak and predominantly clockwise daily hysteresis of bed load transport was found for the first half of the summer period.

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Mountains and Montane Channels

Cited by 19 publications

References 92 publications

Climate Change Impacts on Sediment Quality of Subalpine Reservoirs: Implications on Management

Climate Change Impacts on Sediment Quality of Subalpine Reservoirs: Implications on Management

Geomorphic coupling and sediment connectivity in an alpine catchment — Exploring sediment cascades using graph theory

Variability of Bed Load Transport During Six Summers of Continuous Measurements in Two Austrian Mountain Streams (Fischbach and Ruetz)

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