scholarly journals Riparian shading controls instream spring phytoplankton and benthic algal growth

2016 ◽  
Vol 18 (6) ◽  
pp. 677-689 ◽  
Author(s):  
S. J. Halliday ◽  
R. A. Skeffington ◽  
A. J. Wade ◽  
M. J. Bowes ◽  
D. S. Read ◽  
...  
Keyword(s):  
High Frequency ◽  
Algal Growth ◽  
Small River ◽  
Stream Metabolism ◽  
Frequency Monitoring ◽  
Riparian Shading

High-frequency monitoring shows the importance of riparian shading in controlling benthic algal growth and stream metabolism in a small river.

scholarly journals High-resolution monitoring of nutrients in groundwater and surface waters: process understanding, quantification of loads and concentrations, and management applications

2016 ◽  
Vol 20 (9) ◽  
pp. 3619-3629 ◽  
Author(s):  
Frans C. van Geer ◽  
Brian Kronvang ◽  
Hans Peter Broers
Keyword(s):  
High Resolution ◽  
High Frequency ◽  
Temporal Trends ◽  
Surface Water Quality ◽  
Mitigation Measures ◽  
Nutrient Concentrations ◽  
Special Issue ◽  
Monitoring Strategies ◽  
Frequency Monitoring ◽  
Water Quality And Quantity

Abstract. Four sessions on "Monitoring Strategies: temporal trends in groundwater and surface water quality and quantity" at the EGU conferences in 2012, 2013, 2014, and 2015 and a special issue of HESS form the background for this overview of the current state of high-resolution monitoring of nutrients. The overview includes a summary of technologies applied in high-frequency monitoring of nutrients in the special issue. Moreover, we present a new assessment of the objectives behind high-frequency monitoring as classified into three main groups: (i) improved understanding of the underlying hydrological, chemical, and biological processes (PU); (ii) quantification of true nutrient concentrations and loads (Q); and (iii) operational management, including evaluation of the effects of mitigation measures (M). The contributions in the special issue focus on the implementation of high-frequency monitoring within the broader context of policy making and management of water in Europe for support of EU directives such as the Water Framework Directive, the Groundwater Directive, and the Nitrates Directive. The overview presented enabled us to highlight the typical objectives encountered in the application of high-frequency monitoring and to reflect on future developments and research needs in this growing field of expertise.

scholarly journals High-frequency monitoring reveals seasonal and event-scale water quality variation in a temporally frozen river

2018 ◽  
Vol 564 ◽  
pp. 619-639 ◽  
Author(s):  
M. Kämäri ◽  
S. Tattari ◽  
E. Lotsari ◽  
J. Koskiaho ◽  
C.E.M. Lloyd
Keyword(s):  
Water Quality ◽  
High Frequency ◽  
Event Scale ◽  
Water Quality Variation ◽  
Frequency Monitoring ◽  
Quality Variation

Lena River biogeochemistry resolved by a high frequency monitoring: comparing a wet and a dry year

2021 ◽  
Author(s):  
Bennet Juhls ◽  
Anne Morgenstern ◽  
Pier Paul Overduin
Keyword(s):  
Organic Carbon ◽  
High Frequency ◽  
Monitoring Program ◽  
The Arctic ◽  
Lena River ◽  
O Isotopes ◽  
The Arctic Ocean ◽  
Frequency Monitoring ◽  
Biogeochemical Parameters ◽  
Doc Flux

<p>River biogeochemistry at any location integrates environmental processes over a definable upstream area of the river watershed. Therefore, biogeochemical parameters of river water are powerful indicators of the climate change impact on the entire watershed and smaller parts of it.</p><p>The current warming of the Siberian Arctic is changing atmospheric forcing, precipitation, subsurface water storage, and runoff from rivers to the Arctic Ocean. A number of studies predict an increase of organic carbon export by rivers into the Arctic Ocean with further warming of the Arctic. Major potential drivers for this increase are the rise of river discharge and permafrost thaw, which mobilizes organic matter.</p><p>Here, we present results of high frequency monitoring program of the Lena River waters in the central part of its delta at the Laptev Sea. For the first time, a number of biogeochemical parameters such as dissolved organic carbon (DOC), coloured dissolved organic matter, electrical conductivity, temperature, and d<sup>18</sup>O isotopes were measured at an interval of every few days throughout the entire season. Currently, the data set comprises two complete years from the spring 2018 until the spring 2020, which were characterized by extremely high and low summer discharges, respectively. While 2018 to 2019 was the fourth highest on record from 1936 to present, resulting in an annual DOC flux of 6.8 Tg C yr<sup>-1</sup>, 2019 was the sixth lowest discharge year with a significantly lower DOC flux of 4.5 Tg C yr<sup>-1</sup>. Endmember analysis using electrical conductivity and d<sup>18</sup>O isotopes showed that rainwater transported less DOC in 2019 (1.5 Tg C) than in 2018 (2.9 Tg C) although the winter base flow and the snow and ice meltwater transported similar amounts.</p><p>The biogeochemical response of the Lena River water provides us with new insights into the catchment processes, including permafrost thaw and potential mobilization of previously frozen organic carbon. Our new monitoring program will serve 1) as a baseline to measure future changes and 2) as a training dataset to project changes under future climate scenarios.</p>

Beyond high frequency monitoring: an optimised automatic sampling

2021 ◽  
Author(s):  
Jérémy Mougin
Keyword(s):  
Organic Matter ◽  
Water Body ◽  
High Frequency ◽  
Passive Samplers ◽  
Size Exclusion ◽  
Strong Impact ◽  
Small Stream ◽  
Automatic Sampling ◽  
Frequency Monitoring ◽  
On Line

<p>Beyond high frequency monitoring : an optimised automatic sampling</p><p>Mougin Jérémy, Superville Pierre-Jean, Cornard Jean-Paul, Billon Gabriel</p><p> </p><p>In order to improve the representativity of samples when monitoring a water body, efforts have been made these last years to develop new methodologies to replace grab samples. Passive samplers have allowed to have measurement averaged over several days and represented a first step. High frequency monitoring (usually one measure per hour), either in situ or on-line, led to the observations of daily cycles or transitory phenomena that were not suspected beforehand.</p><p>However, such method is usually difficult to implement for some trace analytes (e.g. trace metals or pesticides) or for some specific analysis (e.g. size exclusion chromatography on natural organic matter). Automatic sampling and analysis in the lab can be a solution, but it becomes very labor intensive as soon as the sampling frequency is high. Luck is also needed as a long sampling period can sometimes lead to very few variations if the water system is stable. In order to optimise the automatic sampling, a new methodology has been developped in this project.</p><p>A multiparameter probe measuring general parameters (temperature, pH, turbidity, ORP, conductivity, dissolved oxygen and two fluorometers for organic matter) was coupled with an automatic filtering sampler. The data from the probe are processed on-line and an algorithm decides if the geochemical situation in the water body seems new enough to trigger the sampling, based on previously sampled waters. The aim of this device is to collect the right number of samples with the best representativeness of phenomena taking place in the environment.</p><p>This method will be tested over a year in 2021 in order to monitor the dissolved organic matter in a small stream with both rural and urban contamination. These high-frequency measurements and samplings could make it possible to better define the sources and dynamics of the organic matter that has a strong impact on the quality of watercourses.</p>

scholarly journals Time scales of arsenic variability and the role of high-frequency monitoring at three water-supply wells in New Hampshire, USA

2020 ◽  
Vol 709 ◽  
pp. 135946 ◽  
Author(s):  
James R. Degnan ◽  
Joseph P. Levitt ◽  
Melinda L. Erickson ◽  
Bryant C. Jurgens ◽  
Bruce D. Lindsey ◽  
...  
Keyword(s):  
Water Supply ◽  
Time Scales ◽  
New Hampshire ◽  
High Frequency ◽  
Frequency Monitoring

scholarly journals High-frequency monitoring reveals nutrient sources and transport processes in an agriculture-dominated lowland water system

2016 ◽  
Vol 20 (5) ◽  
pp. 1851-1868 ◽  
Author(s):  
Bas van der Grift ◽  
Hans Peter Broers ◽  
Wilbert Berendrecht ◽  
Joachim Rozemeijer ◽  
Leonard Osté ◽  
...  
Keyword(s):  
Water Quality ◽  
High Frequency ◽  
Preferential Flow ◽  
Temporal Dynamics ◽  
Water Systems ◽  
Transport Processes ◽  
Rainfall Events ◽  
Nutrient Sources ◽  
Pumping Station ◽  
Frequency Monitoring

Abstract. Many agriculture-dominated lowland water systems worldwide suffer from eutrophication caused by high nutrient loads. Insight in the hydrochemical functioning of embanked polder catchments is highly relevant for improving the water quality in such areas or for reducing export loads to downstream water bodies. This paper introduces new insights in nutrient sources and transport processes in a polder in the Netherlands situated below sea level using high-frequency monitoring technology at the outlet, where the water is pumped into a higher situated lake, combined with a low-frequency water quality monitoring programme at six locations within the drainage area. Seasonal trends and short-scale temporal dynamics in concentrations indicated that the NO3 concentration at the pumping station originated from N loss from agricultural lands. The NO3 loads appear as losses via tube drains after intensive rainfall events during the winter months due to preferential flow through the cracked clay soil. Transfer function-noise modelling of hourly NO3 concentrations reveals that a large part of the dynamics in NO3 concentrations during the winter months can be related to rainfall. The total phosphorus (TP) concentration and turbidity almost doubled during operation of the pumping station, which points to resuspension of particulate P from channel bed sediments induced by changes in water flow due to pumping. Rainfall events that caused peaks in NO3 concentrations did not results in TP concentration peaks. The rainfall induced and NO3 enriched quick interflow, may also be enriched in TP but retention of TP due to sedimentation of particulate P then results in the absence of rainfall induced TP concentration peaks. Increased TP concentrations associated with run-off events is only observed during a rainfall event at the end of a freeze–thaw cycle. All these observations suggest that the P retention potential of polder water systems is primarily due to the artificial pumping regime that buffers high flows. As the TP concentration is affected by operation of the pumping station, timing of sampling relative to the operating hours of the pumping station should be accounted for when calculating P export loads, determining trends in water quality, or when judging water quality status of polder water systems.

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