• Journal of Environmental Science International
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• v.1 no.2
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• pp.49-57
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• 1992

First, We classified man-made lakes in Korea as 4-type lakes, that is, there were River-run lakes, Dendritic lakes, Reservoir-lakes, River-mouth lakes, We studied on the environmental factors of 3-type lakes except River-mouth lakes, compared these lakes with natural lakes in foreign country. Environmental factors were watershed area, lake storage, mean depth, hydraulic retention time. As a results, 3-type lakes in Korea had remarkable differences one another according to above-mentioned environmental factors. First, We recognized that River-run lakes had higher nutrient loading according to having wider watershed area than natural lakes, and had lower algal growth rate according to shorter hydraulic retention time than natural lakes. Dendritic lake had higher nutrient loading than natural lakes, longer retention time than River-run lake. Reservoir-lakes had environmental factors between Dentritic lakes and River-run lakes. Therefore, If this studies had no quantitative results about various factors, We recognized that man-made lakes in korea had different environmental factors as compared with natural lakes, and had clear classification among 3-type lakes.

• Journal of Environmental Science International
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• v.13 no.1
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• pp.11-17
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• 2004

The purpose of this study is to present the model of ecological restoration through analysis on the condition of hydrach succession process in brackish water lake. To this study, we investigate and research the present condition of brackish water lake in South Korea. Most brackish water lake in South Korea have characteristics that is come into being malignant hydrach succession. Many lakes were reclaimed to increase foodstuff production. And river conservation work seperate lakes from the ocean. In a embryological view, most lakes based on the brackish water lakes, But present lakes show many different types such as a fresh water lake, a salt lake, a brackish water lake, a swamp, and a marshland. As a result, brackish water lakes have greatly damaged by diverse artificial interventions to promote people's activities. Therefore, in order to manage brackish water lakes systematically, criteria of lake preservation must be coincide with the present conditions of hydrach succession in each lake.

• KCID journal
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• v.19 no.1
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• pp.19-29
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• 2012

The data of the agricultural water quality survey network was analyzed between from 1990 to 2010 in order to propose effective plans for water quality management by analyzing the characteristics of agricultural lakes and the change of water quality. The result of the analysis shows that there is a correlation between water quality and items that can be a function of water depth such as dam height, dam length, dam height/dam length ratio and active storage/surface area of lake ratio. This means that, Korean agricultural lakes, there is a correlation between water quality and water depth. Water quality of the lakes that have lower than 5m of active storage/surface area of lake ratio (effective water depth) especially tends to get worse rapidly. The Chl-a and COD concentration of Korean agricultural lakes have a tendency to increase between June and September. Therefore, we recommend first taking a water quality improvement project for the lakes preformed watershed management project, and taking a preventive short-term water quality improvement project for the unperformed lakes before June among lakes that have lower than 5m of effective water depth.

• 한국생태학회:학술대회논문집
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• 1999.05a
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• pp.43-54
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• 1999

1. Hanoi city was built up on the wetland landscape of the Red River delta therefore it has a network of many lakes and rivers. 2. The aquatic biodiversity (Macrophytes, Invertebrates, Fishes, Vertebrates) of the 6 main lakes (Ho Tay, Hoan Kiem, Bay Mau, Giang Vo, Dong Da, Thanh Nhan) are rich and diverse. It represents the patterns of Red River delta one's. Many rare and endangered species are found in these lakes Particularly a giant freshwater turtle species in Hoan Kiem lake. 3. All of these lakes are more or less polluted. Their environments are seriously degrading both in water quality and aquatic biodiversity. 4. Based on socio-economical and cultural role of these lakes of Hanoi city, it is very necessary to preserve and to restore their environments and aquatic biodiversity: water Pollution control, landscape planning, making roads around the lakes and erosion control for their banks, legislation measures, rational exploitation of aquatic biodiversity, restoration the artificial wetlands with macrophytes.

• Economic and Environmental Geology
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• v.29 no.1
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• pp.77-85
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• 1996

The vertical concentration profiles of chromium in sediment cores were measured from Lakes Superior, Michigan, and Ontario in an attempt to determine spatial and historical variations. Pre-industrial concentrations of chromium are typical for soils in the Great Lakes region. Only Lakes Ontario and Michigan exhibit anthropogenic enrichments of chromium in the sediments. Sediment profiles in Lakes Ontario and Michigan indicate that the rates of anthropogenic chromium loading to the Great Lakes region are decreasing. Focusing corrected inventories are similar within each lake and those are higher in Lake Ontario than Lake Michigan. The results are interpreted to indicate that there is a small atmospheric component to chromium inputs to the Great Lakes and that the relative importance of this input decreases from Lake Superior to Lake Ontario.

• Mycobiology
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• v.30 no.2
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• pp.76-81
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• 2002

Aquatic fungi from four brackish water lakes; Edku, Burullus and Manzala lakes which are located at the northern region of Egypt and Qarun lake that located in El-Fayoum city are reported in this manuscript. Twenty-nine fungal species which belong to 19 genera of aquatic fungi were recovered from water samples collected from the studied lakes. The most frequently isolated fungal species were Chytridium conferrop, Allomyces throughout and Rhizoclosmatium globosum. Thraustochytrium amoeboidum and Leptolegniella exoosporus have a moderately occurrence frequency. The maximum fungal count of recovered aquatic fungi was recorded in Burrullus lake followed by EdKu, Manzala and Qarun lakes. This study was extended to test the ability of six selected aquatic fungi(Brevilegniella keratinophila, Blastocladiella cystogena, Chytridium conferrop, Entophlyctis variabilis, Schizochytrium mangrovei and Thraustochytrium rosin), to uptake the radionuclide from their culture medium as a step to biologically treat the waste water or solution with radio-cesium and radio-cobalt. Fifty seven of Cs-137 and 35% of Co-60 could be removed from liquid waste by the selected aquatic fungi.

• Fisheries and Aquatic Sciences
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• v.26 no.7
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• pp.423-436
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• 2023

The objectives of this review were to synthesize the community structure of phytoplankton and the role of atelomix in the phytoplankton dynamics in Ethiopian highland lakes. Changes in a lake's physical structure, light dynamics, and availability of nutrients are closely associated with phytoplankton ecology, and phytoplankton assemblages provide insight into phytoplank- ton responses to these environmental changes. Based on the available information, a total of 173 species of phytoplankton are grouped under seven classes, Chlorophyceae (80 taxa), Bacillariophyceae (55 taxa), Cyanophyceae (24 taxa), Dinophyceae (6 taxa), Eugleonophyceae (6 taxa), Xanthophyceae (1 taxon), and Cryptophyceae (1 taxon) were recorded in five different tropical Ethiopian highland lakes. Chlorophyceae and Bacillariophyceae dominated in terms of species composition. Partial atelomixis, seasonality, and low nutrient concentrations seem to be the main drivers in structuring phytoplankton composition and abun-dances in Ethiopian highland lakes, characterized by a high diversity of atelomix-dependent benthic diatoms and desmids. Thus, this review will help understand the role of atelomix and nutrient availability in the phytoplankton composition and biomass of tropical highland lakes of Ethiopia.

• Journal of Environmental Impact Assessment
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• v.17 no.6
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• pp.373-380
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• 2008

The Ministry of Environment plans to improve quality of water which is achieved over 85% in rivers and 94% in lakes of the whole country as "Good Water" until 2015. Also, the law of evaluation of water quality and water quality goal were made newly. So, the water quality has evaluated by using new law since 2007. This study evaluated whether "Good Water" and" Water Quality Goal" were achieved or not in 22 middle-sized districts and major 10 lakes of Geum river. The achievement rates of rivers decreased and the achievement rates of lakes mostly were the same for 5 years. In 2007, the achievement rates of "Good Water" were 50% in rivers and 50% in lakes. The achievement rate of "Water Quality Goal" were 59.1% in rivers and 20% in lakes. The water quality in 2007 was evaluated worse than last year in case of rivers. The evaluations of Korea-Comprehensive Water Quality Index(K-CWQI) showed that achievement rates of "Water Quality Goal" were 81.8% in rivers and 0% in lakes. The statistical correlation analysis showed that correlations between BOD and COD were meaningful at the downstream, compared to upstream, generally. In case of lakes, correlations between COD and temperature were meaningful. Also, correlations between COD and Chl-a were meaningful. The Trophic State Index ($TSI_{KO}$) showed that the half of lakes are major over eutrophic status in lakes. These analytical methods such as K-CWQI, $TSI_{KO}$, statistical correlation analysis could be additionally helpful for evaluation of water quality and provide basis data for understanding characteristics of watershed in Geum river.

• Journal of Korean Society on Water Environment
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• v.35 no.3
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• pp.271-277
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• 2019

Korean Trophic State Index ($TSI_{KO}$) was developed in 2006, and was composed of COD ($COD_{Mn}$ based on permanganate method), Chlorophyll a (Chl.a) and total phosphorus (TP). However, $COD_{Mn}$ usually represents only 50-60% of total organic matter in stream or lake water due to low oxidizing power of permanganate. This study investigated the relationship between TOC and $COD_{Mn}$ based on the average data for the whole layer in 81 lakes in Korea, during the period 2013-2017. As a result, $COD_{Mn}$ was found to be 1.54 times more than TOC in 66 of the freshwater lakes and 3 brackish lakes (TOC measured using thermo-oxidation method). TOC was about a quarter of $COD_{Mn}$ in 8 coastal lakes (TOC measured using UV-persulfate oxidation method), and it appeared to be underestimated due to chloride interference. Using the data of 69 lakes with exception of 12 brackish lakes, $TSI_{KO}$(TOC) was developed based on the correlation between TOC and $COD_{Mn}$, while $TSI_{KO}$(COD) was replaced with $TSI_{KO}$(TOC). However, for trophic state assessment of brackish lakes, the $TSI_{KO}$(TOC) can only be utilized in case that TOC is measured through thermo-oxidation method. The determination coefficient of $TSI_{KO}$(Chl) to $TSI_{KO}$(COD) in 66 freshwater lakes and 3 brackish lakes was 0.83, while that to $TSI_{KO}$(TOC) was 0.68. This difference could be attributed to the recalcitrant organic part of TOC.

• Korean Journal of Ecology and Environment
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• v.40 no.4
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• pp.553-559
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• 2007

The vertical distributions of sulfate reducing bacteria (SRB) in sediments of lakes in Korea (Lake Sihwa and Lake Soyang) and China (Lake Aha and Lake Erhai) were investigated by fluorescence in situ hybridization (FISH). SRB from sediment of Lakes of China were located to deeper layer than those in Lakes of Korea. SRB were not detected below 19 cm and 10 cm depth in sediments of Lake Sihwa and Lake Soyang, respectively. SRB numbers were, however, detected at all observed sediments in Lake Aha and Lake Erhai. In case of lakes in Korea, the proportion of SRB ranged from 2.9 to 25.6% (Lake Sihwa) and ranged from 0.6 to 7.1% (Lake Soyang). For lakes in China, the proportions of SRB were from 0.6 to 19.4% and from 2.9 to 11.2% within sediments from Lake Aha and from Lake Erhai, respectively. The high peaks of SRB numbers in sediments of all lakes were appearing at depths between 0 cm and 2 cm.