Responses in river water quality during summers with extreme weather periods in Europe
(2021) In Student thesis series INES NGEM01 20201Dept of Physical Geography and Ecosystem Science
- Abstract
- Europe has experienced several climate extremes during the past decades. These extreme events have increased in number and intensity and are projected to further intensify. Previous studies show that heatwaves, drought, and flood can have an impact on water quality in several ways. Drought can cause reduced dilution of nutrients, limiting oxygen availability as a result of increased water temperature, and reduced primary production are all example of such impacts and which can affect many biological processes. The aim of this study was to determine the impact on water quality caused by extreme events over a wider geographical extent covering Europe and across multiple rivers. This was done by using Waterbase database, water sample data... (More)
- Europe has experienced several climate extremes during the past decades. These extreme events have increased in number and intensity and are projected to further intensify. Previous studies show that heatwaves, drought, and flood can have an impact on water quality in several ways. Drought can cause reduced dilution of nutrients, limiting oxygen availability as a result of increased water temperature, and reduced primary production are all example of such impacts and which can affect many biological processes. The aim of this study was to determine the impact on water quality caused by extreme events over a wider geographical extent covering Europe and across multiple rivers. This was done by using Waterbase database, water sample data retrieved during the years 2013-2015, and climate data retrieved from Copernicus Climate Change Service. Changes in the concentration of dissolved oxygen, nitrate, phosphate and chlorophyll-a during years that experienced summer climate extremes (2013 and 2015) relative to the values of a reference year were tested statistically, and further explored through correlation and regression analyses. The nutrients and dissolved oxygen were expected to increase and decrease, respectively, with higher air temperature, especially in rivers with small catchment areas. Dissolved oxygen concentrations increased significantly during 2013 and 2015 at mid latitudes compared to concentrations in 2014. A spearman’s correlation analysis was performed to determine any driver of the oxygen concentration patterns, showing a significant correlation between temperature and concentrations and both mid and high latitudes. To visualize the results of the correlation analysis, a linear regression was performed on the relationship between temperature and concentration of dissolved oxygen and showed significant results at both mid and high latitude, though contradictory to each other. No significant differences between concentrations of neither nutrient nor chlorophyll and year were found. Therefore, results were only in part consistent with findings of previous studies, making an overall interpretation difficult and not straightforward. The question about the effect of climate extremes on water quality is complex and includes a variety of variables not accounted for, but potentially highly influential on the parameters used in this study. Additionally, a more geographical spread of sample locations, and a higher consistency in sampling, and increase in frequency, would allow for a more robust and precise analysis. (Less)
- Popular Abstract (Swedish)
- Det senaste decenniet har flera allvarliga perioder och händelser av extremväder drabbat Europa. Tidigare studier visar att dessa händelser och perioder har ökat i antal och i intensitet och en fortsatt intensifiering är förväntad i framtiden. Extremväder såsom värmeböljor, torka och floder kan påverka vattenkvalitén i våra floder på olika sätt. Det är viktigt då flodernas ekologi är grundläggande för Europa på flera sätt. Floder är rika på biologisk mångfald, en källa för mat och dricksvatten för människan, ger vattenkraft och bevattning inom jordbruket.
Under perioder av torka minskar tillförseln av vatten från nederbörd till floderna vilket kan göra att koncentrationer ökar då det under normala förhållanden skulle spädas ut. En ökande... (More) - Det senaste decenniet har flera allvarliga perioder och händelser av extremväder drabbat Europa. Tidigare studier visar att dessa händelser och perioder har ökat i antal och i intensitet och en fortsatt intensifiering är förväntad i framtiden. Extremväder såsom värmeböljor, torka och floder kan påverka vattenkvalitén i våra floder på olika sätt. Det är viktigt då flodernas ekologi är grundläggande för Europa på flera sätt. Floder är rika på biologisk mångfald, en källa för mat och dricksvatten för människan, ger vattenkraft och bevattning inom jordbruket.
Under perioder av torka minskar tillförseln av vatten från nederbörd till floderna vilket kan göra att koncentrationer ökar då det under normala förhållanden skulle spädas ut. En ökande vattentemperatur till följd av värmeböljor kan minska koncentrationen av löst syre i floderna då lösligheten av syre minskar med varmare vattentemperaturer. Flera av dessa konsekvenser påverkar i sin tur biologiska processer som är viktiga för vattenkvalitén i våra floder. Då tidigare studier på hur vattenkvalité i floder kan påverkas av extrema väderperioder eller händelser är begränsade geografiskt eller i antal floder studerade var syftet med den här studien att därför att studera påverkan på vattenkvalitén av extrem väder/perioder i en större skala genom att se på hela Europa. Tidsramen bestämdes utefter tillgängligheten av vattendata och rapporterade extremvädersperioder och blev satt till juni-augusti under åren 2013–2015 där 2014 användes som referensår. Vattendata för analys till studien kom från Waterbase databas, utvecklat av Europeiska miljöbyrån (European Environmental Agency), och klimatdata, i detta fall lufttemperatur och nederbörd, från Copernicus (Copernicus Climate Change Service). Floder delades in i 3 latitudgrupper och 3 grupper beroende på storleken på avrinningsområdet. Statistiska analyser utfördes för att se om eventuella skillnader i vattenkvalitén mellan extrem-år och referensåret var statistiskt signifikanta. Baserat på de resultaten utfördes korrelationsanalyser för att studera eventuell relation mellan olika vattenkvalitéparametrar och lufttemperatur eller nederbörd. Resultatet visade att löst syre var signifikant högre under 2013 och 2015 extremväder i centrala Europa. Det två andra latitudgrupperna och grupperna baserat på olika storlek på avrinningsområden visade inga signifikanta resultat. Näringsämnen och klorofyll-a visade inga signifikante skillnader mellan år av extrema väderperioder och referensperiod. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9041902
- author
- Claeson, Felicia LU
- supervisor
-
- Martin Berggren LU
- Zheng Duan LU
- organization
- course
- NGEM01 20201
- year
- 2021
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- water quality, rivers, Europe, extremeweather periods, drought, heatwave, floods, dissolved oxygen, nitrate, chlorophyll-a, phosphate
- publication/series
- Student thesis series INES
- report number
- 532
- language
- English
- id
- 9041902
- date added to LUP
- 2021-03-15 12:52:08
- date last changed
- 2021-03-15 12:52:08
@misc{9041902,
abstract = {{Europe has experienced several climate extremes during the past decades. These extreme events have increased in number and intensity and are projected to further intensify. Previous studies show that heatwaves, drought, and flood can have an impact on water quality in several ways. Drought can cause reduced dilution of nutrients, limiting oxygen availability as a result of increased water temperature, and reduced primary production are all example of such impacts and which can affect many biological processes. The aim of this study was to determine the impact on water quality caused by extreme events over a wider geographical extent covering Europe and across multiple rivers. This was done by using Waterbase database, water sample data retrieved during the years 2013-2015, and climate data retrieved from Copernicus Climate Change Service. Changes in the concentration of dissolved oxygen, nitrate, phosphate and chlorophyll-a during years that experienced summer climate extremes (2013 and 2015) relative to the values of a reference year were tested statistically, and further explored through correlation and regression analyses. The nutrients and dissolved oxygen were expected to increase and decrease, respectively, with higher air temperature, especially in rivers with small catchment areas. Dissolved oxygen concentrations increased significantly during 2013 and 2015 at mid latitudes compared to concentrations in 2014. A spearman’s correlation analysis was performed to determine any driver of the oxygen concentration patterns, showing a significant correlation between temperature and concentrations and both mid and high latitudes. To visualize the results of the correlation analysis, a linear regression was performed on the relationship between temperature and concentration of dissolved oxygen and showed significant results at both mid and high latitude, though contradictory to each other. No significant differences between concentrations of neither nutrient nor chlorophyll and year were found. Therefore, results were only in part consistent with findings of previous studies, making an overall interpretation difficult and not straightforward. The question about the effect of climate extremes on water quality is complex and includes a variety of variables not accounted for, but potentially highly influential on the parameters used in this study. Additionally, a more geographical spread of sample locations, and a higher consistency in sampling, and increase in frequency, would allow for a more robust and precise analysis.}},
author = {{Claeson, Felicia}},
language = {{eng}},
note = {{Student Paper}},
series = {{Student thesis series INES}},
title = {{Responses in river water quality during summers with extreme weather periods in Europe}},
year = {{2021}},
}