scholarly journals Successful forecasting of harmful cyanobacteria blooms with high frequency lake data

2019 ◽  
Author(s):  
M.J. Kehoe ◽  
B.P. Ingalls ◽  
J.J. Venkiteswaran ◽  
H.M. Baulch
Keyword(s):  
Water Temperature ◽  
High Frequency ◽  
Cyanobacterial Blooms ◽  
Forecasting Accuracy ◽  
Forecasting Models ◽  
Treatment Processes ◽  
Cyanobacteria Blooms ◽  
Frequency Monitoring ◽  
Sparse Measurements ◽  
Derivatives Of

AbstractCyanobacterial blooms are causing increasing issues across the globe. Bloom forecasting can facilitate adaptation to blooms. Most bloom forecasting models depend on weekly or fortnightly sampling, but these sparse measurements can miss important dynamics. Here we develop forecasting models from five years of high frequency summer monitoring in a shallow lake (which serves as an important regional water supply). A suite of models were calibrated to predict cyanobacterial fluorescence (a biomass proxy) using measurements of: cyanobacterial fluorescence, water temperature, light, and wind speed. High temporal autocorrelation contributed to relatively strong predictive power over 1, 4 and 7 day intervals. Higher order derivatives of water temperature helped improve forecasting accuracy. While traditional monitoring and modelling have supported forecasting on longer timescales, we show high frequency monitoring combined with telemetry allows forecasting over timescales of 1 day to 1 week, supporting early warning, enhanced monitoring, and adaptation of water treatment processes.

scholarly journals High-frequency monitoring of stream water physicochemistry on sub-Antarctic Marion Island

Water SA ◽  
2018 ◽  
Vol 44 (2 April) ◽  
Author(s):  
M-J Stowe ◽  
DW Hedding ◽  
FD Eckardt ◽  
W Nel
Keyword(s):  
Electrical Conductivity ◽  
High Resolution ◽  
Water Temperature ◽  
Total Variation ◽  
High Frequency ◽  
Stream Water ◽  
Precipitation Event ◽  
Induced Response ◽  
Marion Island ◽  
Frequency Monitoring

Given the remoteness and challenging environmental conditions on sub-Antarctic Marion Island, continuous high-resolution studies of the island’s natural water systems are rare. Subsequently, current understanding of the island’s hydrochemistry is based entirely on manual point-based measurements. To address this research gap we analysed continuous, in-situ high-frequency physicochemical measurements (pH, water temperature, dissolved oxygen (DO), and electrical conductivity (EC)) from the Soft Plume River over the period 21 April 2015–26 April 2015. We observed a sharp, short-term response from all measurements to a precipitation event that was superimposed on consistent but subtle diel (i.e. 24 h) cycles throughout the study. Total variation in pH and electrical conductivity amounted to 1.3 units and 27.7 μS/cm respectively. Stream water temperature was less variable (6.2°C) than air surface temperature (14.2°C). Total variation in DO was 2.0 mg/L. Aside from the precipitation-induced response, diel oscillations were small and only visible through the use of continuous, high-resolution monitoring. Findings highlight the advantages of continuous high-frequency monitoring in capturing the range of daily variation and elucidating diel cycles in stream water physicochemistry on sub-Antarctic Marion Island that have not previously been accounted for.

scholarly journals EFFICIENCY EVALUATION OF AN ALGISTATIC TREATMENT BASED ON BARLEY STRAW IN A HYPERTROPHIC POND

2014 ◽  
Vol 22 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Emilie Prygiel ◽  
Adeline Charriau ◽  
Romain Descamps ◽  
Jean Prygiel ◽  
Baghdad Ouddane ◽  
...  
Keyword(s):  
Primary Production ◽  
Chlorophyll A ◽  
Green Algae ◽  
High Frequency ◽  
Barley Straw ◽  
Efficiency Evaluation ◽  
Diatom Bloom ◽  
Cyanobacteria Blooms ◽  
Frequency Monitoring ◽  
Good Oxygenation

Eutrophication processes were closely examined in a hypertrophic pond that was subjected to a barley straw treatment to inhibit cyanobacteria blooms. A phytoplankton activity was present from February to November 2010 with Chlorophyll a concentrations that ranged between 8 and 83 μg L-1 . The good oxygenation of the pond provided by primary production all along the year seems to maintain an oxic layer at the top of the sedimentary column. A high-frequency monitoring of algal development pointed out the end of the diatom bloom at the end of April and the growth of green algae from beginning of May. One month later, the development of cyanobacteria supplanted other algae several times. The implementation of barley straw does not seem to hinder the growth of cyanobacteria in June, August and September and do not promote the development of other algae potentially favoured by such a treatment. As a consequence, a barley straw treatment does not seem to be really appropriate for this kind of ponds in Northern France and more tests should still be undertaken to prove its real efficiency.

scholarly journals A Simple Solution for Refining Lake Water Temperature Profiles Data Arrayed from High-Frequency Monitoring Sensors

2021 ◽  
Vol 6 (1) ◽  
pp. 25
Author(s):  
Arianto Budi Santoso ◽  
Endra Triwisesa ◽  
Muh Fakhrudin
Keyword(s):  
Water Temperature ◽  
High Frequency ◽  
Information Filtering ◽  
Temperature Data ◽  
Simple Solution ◽  
Temperature Profiles ◽  
West Sumatra ◽  
Frequency Monitoring ◽  
Water Temperature Data ◽  
Upper Mixed Layer

The revolutionized aquatic monitoring sensors are essential in capturing environmental patterns that traditional discrete samplings might not be able to. They allow scientists to further synthesize and better conclude processes in aquatic ecosystems. These sensors produce high-frequency data that provide information on a fine temporal scale, even near real-time. The massive quantities of the streamed data, however, create challenges for scientists to grasp the concrete information. Filtering data quality, on the other hand, is another problem scientists might have encountered as sensor accuracy and precision may drift along the line. Hence, quality assurance and quality control might be quite labouring owing to the size of datasets to handle. This paper proposed a semi-mechanistic algorithm to improved false water temperature data. Using “theoretical” thermal stratification as a reference, this algorithm fixed sensors error readings. A 5-month dataset of water temperature profiles of Lake Maninjau, West Sumatra, captured every 10 minutes from a set of sensors in thermistor chain was applied. We found that most data fit to the theoretical temperature profile, R<sup>2</sup> = 0.962, RMSE = 0.081<sup>o</sup>C. A number of errors, however, were observed in the upper layer of the lake (&lt;20 m), the most dynamic layer in terms of its thermal variation. Sensor drifts in this active upper mixed layer can be related to the generated errors. Through this simple solution, not only improving the quality of the observed water temperature data, but was also able to identify the most probable source of errors

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

&lt;p&gt;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.&lt;/p&gt;&lt;p&gt;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.&lt;/p&gt;&lt;p&gt;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&lt;sup&gt;18&lt;/sup&gt;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&lt;sup&gt;-1&lt;/sup&gt;, 2019 was the sixth lowest discharge year with a significantly lower DOC flux of 4.5 Tg C yr&lt;sup&gt;-1&lt;/sup&gt;. Endmember analysis using electrical conductivity and d&lt;sup&gt;18&lt;/sup&gt;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.&lt;/p&gt;&lt;p&gt;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.&lt;/p&gt;

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

&lt;p&gt;Beyond high frequency monitoring&amp;#160;: an optimised automatic sampling&lt;/p&gt;&lt;p&gt;Mougin J&amp;#233;r&amp;#233;my, Superville Pierre-Jean, Cornard Jean-Paul, Billon Gabriel&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;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.&lt;/p&gt;&lt;p&gt;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.&lt;/p&gt;&lt;p&gt;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.&lt;/p&gt;&lt;p&gt;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.&lt;/p&gt;

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