Landscape influence on small-scale water temperature variations in a moorland catchment

Acknowledgements Iain Malcolm and staff at Marine Scotland (Pitlochry) are thanked for the provision of data from the AWS. Finally, the two anonymous reviewers are greatly acknowledged for their constructive comments.Peer reviewedPostprin

Modelling landscape controls on dissolved organic carbon sources and fluxes to streams

Acknowledgments We thank the Natural Environment Research Council NERC (project NE/K000268/1) for funding. Iain Malcolm and staff at Marine Scotland (Pitlochry) are also thanked for the provision of data from the AWS as are the Scottish Environmental Protection Agency and British Atmospheric Data Centre for the provision of meteorological data.Peer reviewedPublisher PD

A probabilistic approach to quantifying hydrologic thresholds regulating migration of adult Atlantic salmon into spawning streams

Acknowledgment Data to support this study are provided by the Marine Scotland Science Freshwater Laboratory (MSS-FL) and are available for free download on line [Glover and Malcolm, 2015a, 2015b].Peer reviewedPublisher PD

Seasonality, water quality trends and biological responses in four streams in the Cairngorm Mountains, Scotland

The chemical composition and invertebrate communities found in four streams in the Cairngorms, Scotland, were monitored between 1985-1997. Stream waters were mildly acidic (mean pH ca. 6.5), with low alkalinity (mean acid neutralising capacity varying from 35-117 meq l^-1) and low ionic strength. Subtle differences in the chemistry of each stream were reflected in their invertebrate faunas. Strong seasonality in water chemistry occurred, with the most acid, low alkalinity waters observed during the winter and early spring. This was particularly marked during snowmelt between January and April. In contrast, summer flows were usually groundwater dominated and characterised by higher alkalinity and higher concentrations of most other weathering-derived solutes. Seasonality was also clear in the invertebrate data, with Canonical Correspondence Analysis (CCA) separating seasonal samples along axes related to water temperature and discharge characteristics. Inter-annual hydrological and chemical differences were marked, particularly with respect to the winter period. Invertebrate communities found in each of the streams also varied from year to year, with spring communities significantly more variable (<i>P</i><0.01) than other seasons (quantified using Euclidean distance on CCA ordinations). <br>Hydrochemical trends over the study period were analysed using a seasonal Kendall test, LOcally WEighted Scatterplot Smoothing (LOWESS) and graphical techniques. These indicated that a reduction in sulphate concentrations in stream water is occurring, consistent with declining levels of atmospheric deposition. This may be matched by increases in pH and declining calcium concentrations, though available evidence is inconclusive. Other parameters, such as chloride, total organic carbon and zinc, reveal somewhat random patterns, probably reflecting irregular variations in climatic factors and/or atmospheric deposition. Previous studies have shown that the stream invertebrate communities have remained stable over this period (i.e. no significant linear trends) and show no evidence of acid-related impoverishment. Thus, over longer timescales invertebrates in these streams appear robust to the short-term (seasonal and inter-annual) environmental variability and long-term (decadal) chemical changes identified.</p> <p style='line-height: 20px;'><b>Keywords: </b>hydrochemistry, hydrology, trends, macroinvertebrates, uplands, Cairngorms, acidificatio

Visualisation of spatial patterns of connectivity and runoff ages derived from a tracer-aided model

We thank the European Research Council ERC (project GA 335910 VEWA) for funding the VeWa project.Peer reviewedPostprin

Stream water age distributions controlled by storage dynamics and nonlinear hydrologic connectivity : Modeling with high-resolution isotope data

Peer reviewedPublisher PD

Modelling storage-driven connectivity between landscapes and riverscapes : towards a simple framework for long-term ecohydrological assessment

Acknowledgements: We thank Iain Malcolm of Marine Scotland Science for access to data from the Girnock and the Scottish Environment Protection Agency for historical stage-discharge relationships. CS contributions on this paper were in part supported by the NERC/JPI SIWA project (NE/M019896/1).Peer reviewedPublisher PD

Scaling effects of riparian peatlands on stable isotopes in runoff and DOC mobilization

Acknowledgments The authors would like to thank the European Research Council ERC (project GA 335910 VeWa) for funding the VeWa project. Part of this work was funded through the Natural Environment Research Council (NERC) (project NE/K000268/1). We would also like to thank our NRI colleagues for all their help with field and laboratory work, especially Jason Lessels, Matthias Sprenger, Jonathan Dick, Audrey Innes and Ann Porter. We would like to also thank Iain Malcolm (Marine Scotland Science) for providing AWS and Girnock flow data. Please contact the authors for access to the data used in this paper.Peer reviewedPostprin

Role of riparian wetlands and hydrological connectivity in the dynamics of stream thermal regimes

Stream temperature is a fundamental physical characteristic of rivers, influencing biological productivity and water quality. Given the implications of climate warming for stream thermal regimes, it is an important consideration in river management plans. Energy exchanges at the water–air interface, channel geomorphology, riparian vegetation and advective heat transport from the different sources of discharge can all influence stream temperature. A simple mixing equation was used to investigate heat transport and to estimate daily mean and maximum stream temperatures on the basis of mixing groundwater and near-surface flows from riparian wetlands as end-members in a peatland catchment. The resulting data were evaluated against energy balance components and saturation extent to investigate the importance of riparian wetlands in determining stream temperatures. Data fit was generally good in periods with extensive saturation; and poorest in dry periods with less hydrological connectivity, when reduced saturation and low flows increased the relative influence of energy exchange at the stream–atmosphere interface. These findings have implications in terms of climate change and land management, where the planting of riparian buffer strips to moderate water temperatures may be less effective when saturation area is extensive and hydrological connectivity is high

On the Use of StorAge Selection Functions to Assess Time‐Variant Travel Times in Lakes

Funding Information ERC. Grant Number: GA 335910 VeWaPeer reviewedPublisher PD