• Environmental Engineering Research
• /
• v.20 no.1
• /
• pp.19-24
• /
• 2015

This paper mainly focuses on the research of the monitoring data about the total nitrogen (TN), total phosphorus (TP) of ten monitoring points of Hongze Lake in 28 years. Our study adopts the technical methods such as difference comparison, correlation analysis, Mann-Kendall, etc. to analyze the statistical characteristics, regional differences, and temporal and spatial variation condition of ten monitoring points of Hongze Lake in 1986-2013 as well as the reason for the time and space variation of TN and TP. The results show that the TN and TP of Hongze Lake change dramatically during the period of 1994-2004. In all the monitoring periods, TN and TP of the HZ5, HZ6, HZ7, HZ8 monitoring points in the estuary surrounding the Huaihe River are the highest, which suggests that TN and TP of Hongze Lake should not be ignored for the pollution along the Huaihe River. The TN concentration in the core area is the highest, but that in the development control area is the lowest. In most of the years, TN concentration is higher than 2 mg/L, and the water quality is V class and poor V class water quality in China's Environmental Quality Standards for Surface Water (GB3838-2002). TP concentration of the three areas is basically close, that is lower than 2 mg/L in most of the years, and the water quality is within the V class. The TN and TP concentration of Hongze Lake decreased and intensifying trend of eutrophication is controlled after 2004.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.47 no.3
• /
• pp.77-86
• /
• 2005

A monitoring study has been conducted to identify hydrologic conditions, water quality and nutrient loading characteristics of small watershed in Juam Lake. Climate data of the watershed were collected; flow rate was measured and water quality sampling was conducted at the watershed outlet for this study. Water quality data revealed that T-P concentrations meet I grade of lake water quality standard during non-storm period, but degraded up to II-III grade of lake water quality standard during storm period. The observed T-N concentrations always exceeded lake water quality standard. Therefore, T-P was identified as limiting chemical constituent for eutrophication of Juam Lake. T-P concentration of non-storm period also revealed that point source pollution is not serious in the watershed. Three year monitoring results showed that the observed T-N losses were $10.85\~18.88$ kg/ha and T-P losses were $0.028\~0.323$ kg/ha during six month (Mar. - Oct.), respectively. Major portion of runoff amount discharged by a few storm events a year and nutrient load showed apparent seasonal variation. Huge runoff amounts were generated by intense storms, which make application of water treatment or detention facilities ineffective. Monitoring results confirmed that water quality improvement by abating nonpoint source pollution in rural watershed of monsoon climate should be focused on source control. T-P losses from paddy field seemed to consist of significant amount of total load from study watershed. Therefore, management of drainage from paddy field is considered to be important for preventing algal blooming problem in Juam Lake.

• International Journal of Contents
• /
• v.7 no.1
• /
• pp.45-51
• /
• 2011

To protect water pollution and scarcity in lake and river, water quality monitoring applications have become important tools to understand the change of aquatic ecosystem. KLEON (Korean Lake Ecological Observatory Network) is designed to manage and share the ecological observations. The various kinds of water quality and phytoplankton observations are collected from the selected observatories such as seven lakes/rivers/wetlands. To deeply understand the collected observations with weather, KLEON also manages the observatory information such as lake, dam, floodgate, and weather. The accumulated observation and analyzed results are used to improve the water quality index of the observatories and encourage the ecologists' cooperation.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.66 no.2
• /
• pp.25-34
• /
• 2024

The long-term monitoring of the Soyang Lake's water quality, covering 25% of the North Han River watershed, is crucial for effective management of both lake water quality and pollution sources in the broader region. This study utilized continuous monitoring data from the front of the Soyang Dam spanning 2003 to 2022, aiming to analyze trends and provide foundational insights for water quality management. Results revealed a slightly poor grade (IV) for total nitrogen (T-N) in both surface and mid-depth layers, indicating a need for concentrated T-N management. Trend analyses using the Mann-Kendall test and Sen's Slope depicted a decreasing trend in total phosphorus (T-P) for both layers, attributed to non-point source pollution reduction projects initiated after the Soyang Lake's designation as a pollution control area in 2007. The LOWESS analysis showed a T-P increase until 2006, followed by a decrease, influenced by the impact of Typhoon Ewiniar in that year. This 20-year overview establishes a comprehensive understanding of the Soyang Lake's water quality and trends, allowing for a seasonal and periodical analysis of water quality changes. The findings underscore the importance of continued monitoring and management strategies to address evolving water quality issues in the Soyang Lake over time.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.63 no.3
• /
• pp.87-95
• /
• 2021

The Doam Lake Watershed is one of Gangwon-do's non-point source management areas. This area has a lot of snowfall in winter, and it is expected that there will be a lot of soil erosion in early spring due to snow melting. In this study, snow melting was monitored in the Doam Lake watershed from February to 3, 2020. It was conducted to analyze the water quality changes by calculating the concentration of non-point source pollution caused by snowmelt, and to compare the concentration of water quality during snowmelt event with rainfall and non-rainfall event. As a result of water quality analysis, Event Mean Concentration (EMC) at the first monitoring was SS 33.9 mg/L, TP 0.13 mg/L, TN 4.33 mg/L, BOD 1.35 mg/L, TOC 1.84 mg/L. At the second monitoring, EMC were SS 81.3 mg/L, TP 0.15 mg/L, TN 3.12 mg/L, BOD 1.32 mg/L, TOC 3.46 mg/L. In parameter except SS, it showed good water quality. It is necessary to establish management measures through continuous monitoring.

• Journal of Korean Society on Water Environment
• /
• v.20 no.1
• /
• pp.1-11
• /
• 2004

Water quality is monitored at 1,837 points which are streams and sources for water supply in Karea. The monitoring carry out the measurement of 16 parameters of pH, BOD, SS, DO and so on with once a month, and of other parameters such like heavy metal with once a quarter. But most of the monitoring is carried out uncontinuously, so it is very difficult to understand exactly the changes of water quality compared with continuous monitoring. Therefore, real time monitoring system was equipped with basic parameters such as pH, temperature, DO, turbidity and electric conductivity at 25 major sources of water supply after installation of Noryangjin and Dukdo in 1974. But the systems have some problems which cannot be considered the sampling sites to represent for water quality of stream of lake, and can be caused a change of water quality by long distance from analyzer to intake pipe. Therefore, it has carefully to evaluate selection of sample sites for real time monitoring system. Also, problems on the area has been to identify which parameters are best suited to monitoring stream of lake water and the differences, of analyzing results compared with manual analyzing. This paper presents some approaches to handle such problems, namely selection of sampling site and measurable parameters, to connect with bio-monitoring system solving a Limitation of measurable parameters, The bio-monitoring system of an early alarm that is desirable to perceive a toxic material inflow into stream can be applied to continuos water quality monitoring system effectively. Also, this paper presents to build a on line system transmitting immediately from a mobile analyzer house or container to main monitoring center the results of analyzer by a telemeter.

• Journal of Korean Society on Water Environment
• /
• v.35 no.6
• /
• pp.470-480
• /
• 2019

The Doam lake watershed was designated as a non-point pollution management area in 2007 to improve water quality based on watershed management implementation. There have been studies of non-point source reduction with respect to the watershed management impacting the pollutant transport of the reservoir. However, a little attention has been focused on the impact of water quality improvement by the management of the dam operation or the guidelines on the dam operation. In this study, the impact of in-lake management practices combined with watershed management is analyzed, and the appropriate guidelines on the operation of the dam are suggested. The integrated modeling system by coupling with the watershed model (HSPF) and reservoir water quality model (CE-QUAL-W2) was applied for analyzing the impact of water quality management practices. A scenario implemented with sedimentation basin and suspended matter barrier showed decrease in SS concentration up to 4.6%. The SS concentration increased in the scenarios adjusting withdrawal location from EL.673 m to the upper direction(EL.683 m and EL.688 m). The water quality was comparably high when the scenario implemented all in-lake practices with water intake at EL.673 m. However, there was improvement in water quality when the height of the water intake was moved to EL.688 m during the summer by preventing sediments inflow after the rainfall. Therefore, to manage water quality of the Doam lake, it is essential to control the water quality by modulating the height of water intake through consistent turbidity monitoring during rainfall.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2005.04a
• /
• pp.122-126
• /
• 2005

Groundwater monitoring wells (about 70 wells) were extensively installed in 28 sites surrounding Lake Texoma, located on the border of Oklahoma and Texas, to assess the impact of geochemical stressors to shallow groundwater quality. The monitoring wells were classified into three groups (residential area, agricultural area, and oil field area) depending on their land uses. During a two-year period from 1999 to 2001 the monitoring wells were sampled every three months on a seasonal basis. Water quality assay consisted of 25 parameters including field parameters, nutrients, major ions, and trace elements. Occurrence and level of inorganics in groundwater samples were related to the land-use and temporal change.

• Journal of Korea Water Resources Association
• /
• v.57 no.1
• /
• pp.9-19
• /
• 2024

As using public monitoring data, analysing a trends of water quality change, establishing a criteria to determine abnormal status and constructing a regression model that can predict Chlorophyll-a, an indicator of eutrophication, was studied. Accordingly, the three freshwater lakes were selected, approximately 20 years of water quality monitoring data were analyzed for periodic changes in water quality each year using regression analysis, and a method for determining abnormalities was presented by the standard deviation at confidence level 95%. By calculating the temporal change rate of Chlorophyll-a from irregular observed data, analyzing correlations between the rate and other water quality items, and constructing regression models, a method to predict changes in Chlorophyll-a was presented. The results of this study are expected to contribute to freshwater lake water quality management as an approximate water quality prediction method using the statistical model.

• Journal of Korea Water Resources Association
• /
• v.34 no.5
• /
• pp.487-497
• /
• 2001

Investigated data on Lake Okjeong were used for the simulation of water quality. According to the simulation results, the effective scheme of water quality management on reservoir has been proposed. It has been recognized that the water quality of Lake Okjeong is under eutrophic and mesotrophic condition even though there are seasonal variation. The water quality of lake is mainly affected by the inflow of pollutant load from watershed. Therefore, to estimate and quantify the accurate amounts of pollutants flowing into reservoir is absolutely necessary for the effective management of water quality on Lake Okjeong. When the pollutant load measured during 7 different rainy periods in 1999 was compared with total pollutant load in 1999. TN and TP measured during 7 different rainy periods showed almost 50% of total pollutant load. In case of SS, it was 72.8%. On the other hand, the rainfall amount measured during the 7 different rainy periods was about 17.5% of total rainfall amount in 1999. Release rate of TP shows 11.92 mg/L at fish farm site and 0.2∼1.9 mg/L at monitoring station of water quality on Lake Okjeong, and which is considered to be less than that of other foreign reservoirs under the circumstances of anoxic condition. For the effective management of water quality on Lake Okjeong. WASP5 water quality simulation model has been applied and verified, and the verified model was used to propose the effective scheme of water quality management. In this case, 6 different scenarios were applied, by changing the amount of inflow of pollutant load in each subbasin. The most effective scheme has turned out that pollutant load generated from Imsil and Gwanchon subbasin should be reduced, and the best way to improve the water a quality is to reduce the pollutant load at every subbasin. According to the simulation result, wastewater treatment facility should be located at every subbasin.