High-resolution temporal and spatial variation in the water quality of Lake Bolmen, Sweden
(2025) In TVVR 5000 VVRM01 20251Division of Water Resources Engineering
- Abstract
- This study presents a comprehensive analysis of the spatiotemporal dynamics of water quality in Lake Bolmen, southern Sweden, based on high-resolution monitoring data (2022–2024) from five regions. Key parameters—including temperature, dissolved oxygen, pH, turbidity, electrical conductivity, oxidation-reduction potential, and chlorophyll fluorescence—were assessed using data analysis method including quantile regression and kernel density estimation to examine vertical stratification, spatial and temporal variability, and inter-parameter relationships. Results reveal distinct regional and seasonal patterns, with turbidity peaking in late spring and autumn, particularly in the northeastern area, where algal growth exhibits a... (More)
- This study presents a comprehensive analysis of the spatiotemporal dynamics of water quality in Lake Bolmen, southern Sweden, based on high-resolution monitoring data (2022–2024) from five regions. Key parameters—including temperature, dissolved oxygen, pH, turbidity, electrical conductivity, oxidation-reduction potential, and chlorophyll fluorescence—were assessed using data analysis method including quantile regression and kernel density estimation to examine vertical stratification, spatial and temporal variability, and inter-parameter relationships. Results reveal distinct regional and seasonal patterns, with turbidity peaking in late spring and autumn, particularly in the northeastern area, where algal growth exhibits a threshold-dependent dual-phase effect on turbidity. While natural drivers (e.g., wind, precipitation) dominate, sporadic anomalies in conductivity and pH suggest anthropogenic influence. These findings enhance understanding of lake ecosystem responses to environmental stressors and provide a scientific basis for sustainable management of this critical drinking water source. (Less)
- Popular Abstract
- Lake Bolmen, located in southern Sweden, is not only a beautiful natural landmark but also a critical source of drinking water for nearby communities. Over the years, concerns about water quality—such as algal blooms, sediment disturbances, and changes in oxygen levels—have prompted scientists to investigate how the lake's environment functions. This study, conducted from 2022 to 2024, aimed to uncover the hidden patterns in Lake Bolmen's water quality by analyzing data from five different regions of the lake.
Key Findings.
Temperature and Oxygen: A Delicate Balance
Like many lakes, Lake Bolmen experiences seasonal changes in water temperature. In summer, the sun warms the surface, creating distinct layers: a warm top layer... (More) - Lake Bolmen, located in southern Sweden, is not only a beautiful natural landmark but also a critical source of drinking water for nearby communities. Over the years, concerns about water quality—such as algal blooms, sediment disturbances, and changes in oxygen levels—have prompted scientists to investigate how the lake's environment functions. This study, conducted from 2022 to 2024, aimed to uncover the hidden patterns in Lake Bolmen's water quality by analyzing data from five different regions of the lake.
Key Findings.
Temperature and Oxygen: A Delicate Balance
Like many lakes, Lake Bolmen experiences seasonal changes in water temperature. In summer, the sun warms the surface, creating distinct layers: a warm top layer (epilimnion), a middle transition zone (metalimnion), and a cold bottom layer (hypolimnion). These layers prevent mixing, which can lead to oxygen depletion in deeper waters—a problem for fish and other aquatic life. The study found that colder years, like 2023, slowed this process, helping maintain higher oxygen levels.
Algae and Turbidity: A Complicated Relationship
Algae growth, measured by chlorophyll fluorescence, plays a dual role in water clarity. While algae can make water murky, they can also help particles settle, improving clarity. Interestingly, the northeastern part of the lake showed the highest turbidity (cloudiness), likely due to wind stirring up sediments. Algal blooms peaked in late autumn, driven by nutrients from rainfall and decaying organic matter.
Human and Natural Influences
While natural factors like wind, temperature, and rainfall dominated water quality changes, some human impacts were detected. For example, spikes in electrical conductivity (a measure of dissolved ions) in 2022 suggested possible pollution from agricultural runoff. pH levels occasionally dipped below the recommended range for drinking water, highlighting the need for ongoing monitoring.
Regional Differences
The lake isn’t uniform—its regions behave differently. The southern area, for instance, had more stable water temperatures, while the northeast experienced more turbidity. These variations are important for managing the lake, as each region may require tailored strategies to maintain water quality.
Understanding these patterns helps scientists and policymakers protect Lake Bolmen as a vital resource. For example, knowing how wind affects turbidity can guide efforts to reduce sediment disturbance, while tracking oxygen levels ensures healthy habitats for fish. The study also underscores the importance of long-term monitoring to detect emerging threats, such as climate change or pollution.
Future research could benefit from more frequent sampling and additional weather stations around the lake to capture localized effects. By combining this knowledge with sustainable practices, stakeholders can ensure Lake Bolmen remains a clean and reliable water source for generations to come.
Lake Bolmen’s water quality is shaped by a dance of natural forces—wind, temperature, and algae—with occasional human influences. By decoding these patterns, researchers can better safeguard the lake’s health and the communities that depend on it. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9195160
- author
- Jiang, Xuekai LU
- supervisor
- organization
- course
- VVRM01 20251
- year
- 2025
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Lake Bolmen, water quality, stratification, statistic analysis, spatiotemporal variability
- publication/series
- TVVR 5000
- report number
- TVVR-25/5006
- ISSN
- 1101-9824
- language
- English
- additional info
- Examiner. Erik Nilsson
- id
- 9195160
- date added to LUP
- 2025-06-09 16:55:58
- date last changed
- 2025-06-10 09:06:10
@misc{9195160,
abstract = {{This study presents a comprehensive analysis of the spatiotemporal dynamics of water quality in Lake Bolmen, southern Sweden, based on high-resolution monitoring data (2022–2024) from five regions. Key parameters—including temperature, dissolved oxygen, pH, turbidity, electrical conductivity, oxidation-reduction potential, and chlorophyll fluorescence—were assessed using data analysis method including quantile regression and kernel density estimation to examine vertical stratification, spatial and temporal variability, and inter-parameter relationships. Results reveal distinct regional and seasonal patterns, with turbidity peaking in late spring and autumn, particularly in the northeastern area, where algal growth exhibits a threshold-dependent dual-phase effect on turbidity. While natural drivers (e.g., wind, precipitation) dominate, sporadic anomalies in conductivity and pH suggest anthropogenic influence. These findings enhance understanding of lake ecosystem responses to environmental stressors and provide a scientific basis for sustainable management of this critical drinking water source.}},
author = {{Jiang, Xuekai}},
issn = {{1101-9824}},
language = {{eng}},
note = {{Student Paper}},
series = {{TVVR 5000}},
title = {{High-resolution temporal and spatial variation in the water quality of Lake Bolmen, Sweden}},
year = {{2025}},
}