scholarly journals An approach for decomposing river water-quality trends into different flow classes

2021 ◽  
Vol 755 ◽  
pp. 143562
Author(s):  
Qian Zhang ◽  
James S. Webber ◽  
Douglas L. Moyer ◽  
Jeffrey G. Chanat
Keyword(s):  
Water Quality ◽  
River Water ◽  
River Water Quality ◽  
Water Quality Trends

Estimating river water-quality trends under different flow conditions

2021 ◽  
Author(s):  
Qian Zhang ◽  
James Webber ◽  
Douglas Moyer ◽  
Jeffrey Chanat
Keyword(s):  
Water Quality ◽  
River Water ◽  
Total Nitrogen ◽  
Nitrogen Concentration ◽  
High Flow ◽  
River Water Quality ◽  
Low Flow ◽  
Flow Conditions ◽  
Particulate Nitrogen ◽  
Water Quality Trends

<p>A number of statistical approaches have been developed to quantify the overall trend in river water quality, but most approaches are not intended for reporting separate trends for different flow conditions. We propose an approach called FN<sub>2Q</sub>, which is an extension of the flow-normalization (FN) procedure of the well-established WRTDS (“Weighted Regressions on Time, Discharge, and Season”) method. The FN<sub>2Q</sub> approach provides a daily time series of low-flow and high-flow FN flux estimates that represent the lower and upper half of daily riverflow observations that occurred on each calendar day across the period of record. These daily estimates can be summarized into any time period of interest (e.g., monthly, seasonal, or annual) for quantifying trends. The proposed approach is illustrated with an application to a record of total nitrogen concentration (632 samples) collected between 1985 and 2018 from the South Fork Shenandoah River at Front Royal, Virginia (USA). Results show that the overall FN flux of total nitrogen has declined in the period of 1985–2018, which is mainly attributable to FN flux decline in the low-flow class. Furthermore, the decline in the low-flow class was highly correlated with wastewater effluent loads, indicating that the upgrades of treatment technology at wastewater treatment facilities have likely led to water-quality improvement under low-flow conditions. The high-flow FN flux showed a spike around 2007, which was likely caused by increased delivery of particulate nitrogen associated with sediment transport. The case study demonstrates the utility of the FN<sub>2Q</sub> approach toward not only characterizing the changes in river water quality but also guiding the direction of additional analysis for capturing the underlying drivers. The FN<sub>2Q</sub> approach (and the published code) can easily be applied to widely available river monitoring records to quantify water-quality trends under different flow conditions to enhance understanding of river water-quality dynamics. <span>(Journal article: https://doi.org/10.1016/j.scitotenv.2020.143562; R code and data release: https://doi.org/10.5066/P9LBJEY1).</span></p>

scholarly journals Attribution of river water-quality trends to agricultural land use and climate variability in New Zealand

2021 ◽  
pp. NULL
Author(s):  
T. H. Snelder ◽  
C. Fraser ◽  
S. T. Larned ◽  
R. Monaghan ◽  
S. De Malmanche ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
New Zealand ◽  
Climate Variability ◽  
River Water ◽  
Agricultural Land ◽  
River Water Quality ◽  
Agricultural Land Use ◽  
Water Quality Trends

Using historical data to identify future water quality trends at a regional scale

2020 ◽  
Author(s):  
Anna Lintern ◽  
Natalie Kho ◽  
Danlu Guo ◽  
Shuci Liu ◽  
Clement Duvert
Keyword(s):  
Climate Change ◽  
Water Quality ◽  
River Water ◽  
Historical Data ◽  
River Water Quality ◽  
Quality Deterioration ◽  
Droughts And Floods ◽  
Extreme Hydrological Events ◽  
Water Quality Trends ◽  
Water Quality Deterioration

<p>Using historical data to identify future water quality trends</p><ol><li>Lintern</li> <li>Kho</li> <li>Guo</li> <li>Liu</li> <li>Duvert</li> </ol><p> </p><p>Climate change is expected to have a severe impact on water resources management in Australia. This is expected to lead to increasing frequency in extreme hydrological events such as droughts and floods, which will in turn contribute to higher risks of bushfires, fish kills, and water shortage for both humans and the environment. The potential impacts of these climate-change-induced extreme events on the quantity of water available to humans and the environment are relatively well understood. However, we have little understanding of the effect on the water quality of Australian rivers. This project aims to start filling this gap in our understanding.</p><p>Our key objectives are:</p><p>(1) to identify how extreme hydrological events such as droughts and floods have affected river water quality over the last two decades, and explore how spatially variable these impacts have been across the Australian continent.</p><p>(2) to use these past observations as a basis to predict how river water quality will be affected by climate change across the continent, and identify the locations within Australia that will be most vulnerable to water quality deterioration in the near future.</p><p>There is a wealth of historical water quality data for each state in Australia, but these datasets have not yet been investigated systematically to develop a nation-wide understanding of water quality patterns. We believe that only a continental-scale understanding of the response of river water quality to extreme hydrological events will allow for the development of robust predictive models of climate change impacts on water quality. Knowing the potential hotspots for future water quality deterioration will be a key step towards identifying priorities for catchment planning and management.</p><p>In this poster, we will present the preliminary findings of this project by detailing the spatial variability in the impact of hydrological events on water quality across the state of Victoria in South-East Australia.</p>

MULTIVARIATE STATISTICAL ANALYSES OF DANUBE RIVER WATER QUALITY AT GALATI, ROMANIA

2018 ◽  
Vol 17 (5) ◽  
pp. 1249-1266
Author(s):  
Gabriel Murariu ◽  
Paula Popa ◽  
Mihaela Timofti ◽  
Lucian Puiu Georgescu
Keyword(s):  
Water Quality ◽  
River Water ◽  
River Water Quality ◽  
Statistical Analyses ◽  
Danube River ◽  
Multivariate Statistical Analyses ◽  
Multivariate Statistical

Klamath River Water Quality and Acoustic Doppler Current Profiler Data from Link River Dam to Keno Dam, 2007

2008 ◽  
Author(s):  
Annett B. Sullivan ◽  
Michael L. Deas ◽  
Jessica Asbill ◽  
Julie D. Kirshtein ◽  
Kenna D. Butler ◽  
...  
Keyword(s):  
Water Quality ◽  
River Water ◽  
Acoustic Doppler Current Profiler ◽  
River Water Quality ◽  
Klamath River ◽  
Current Profiler ◽  
Profiler Data
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