Water quality above and below pollution sources under low flow situations

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00020699%3A_____%2F23%3AN0000178" target="_blank" >RIV/00020699:_____/23:N0000178 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Water quality above and below pollution sources under low flow situations

Original language description

The identification of river profiles suitable for assessing the effect of drought on water quality includes the entire Czech Republic, however, 46 sources of mainly municipal pollution within the Elbe basin were selected for this contribution. For selected discharge sources, there are situated water quality monitoring sites above and below the wastewater discharge. The share of wastewater discharged from individual selected sources in the flow of watercourses (recipients of wastewater) ranged in the dry period between 1 and 83%. No significant dependence between the size of the discharge source (expressed by both the number of connected inhabitants and the amount of discharged wastewater) and the share of wastewater in the flows in the streams was found. The exception was the largest assessed source, which also had the highest share of discharged wastewater in the stream. This relationship is significantly influenced by the size of the stream into which the wastewater is discharged.To illustrate the water quality situation above and below the discharge sources, the total phosphorus parameter was chosen as the average of the values measured in the summer months. The time period was chosen from 1990, since no measurements are available above discharge sources before that year. Several insights emerge from the graph. Up to about 2004, the concentration ranges are larger than in the later period,but in the later period the occurrence of outliers increased (these situations are often associated with rainfall-runoff events). The situation below the discharge sources is almost always significantly worse than above the sources, although it is not optimal even there (these profiles can be located below other discharge sources). For comparison – the limit for permissible surface water pollution for total phosphorus in Government Regulation No. 401/2015 Coll. is 0.15 mg/l (annual average), and a concentration between 0.03 and 0.07 mg/l (median) is determined for good ecological status of water bodies. For the period from 2006, it is shown that even though the median concentration of total phosphorus above the discharge sources varies in similar values, the situation below the discharge sources differs significantly in individual years. The situation is significantly worse in years 2007 and 2008, 2015, 2017 and 2018, 2022 (median of concentrations above 0.25mg/l).

Czech name

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Czech description

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Type

D - Article in proceedings

CEP classification

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OECD FORD branch

10503 - Water resources

Project

<a href="/en/project/SS02030040" target="_blank" >SS02030040: Prediction, Evaluation and Research for Understanding National sensitivity and impacts of drought and climate change for Czechia</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2023

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Article name in the collection

Magdeburský seminář o ochraně vod 2023

ISBN

978-80-11-03292-0

ISSN

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e-ISSN

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Number of pages

2

Pages from-to

119-120

Publisher name

Povodí Ohře, státní podnik

Place of publication

Chomutov

Event location

Karlovy Vary

Event date

Oct 11, 2023

Type of event by nationality

EUR - Evropská akce

UT code for WoS article

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