• Journal of Korean Society on Water Environment
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• v.40 no.5
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• pp.243-257
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• 2024

Although lakes are an important part of freshwater, research on biological methods for assessing ecological integrity of Korean lakes is insufficient. Therefore, this study aimed to develop Lakes Benthic Macroinvertebrates Multi-Metric Index (LBMMI) to assess the ecological integrity of lakes in Korea to further understand Korean lake's ecosystem. We used biological data from 388 sampling units of national lake monitoring programs from 2022 to 2023 and water quality data from Water Environment Information System (WEIS). As a result, firstly, reference points and disturbed points were selected through Principal Component Analysis (PCA). Secondly, six core metric elements (Pielou's Evenness index (J), Total number of taxa (To.t), Percent of taxa in insecta (% I.t), Percent of individuals in Oligochaeta and chironomidae(tuble) (% OliCht.i), Percent of taxa in Predator (% Pe.t), and Percent of taxa in Clingers (% CL.t) were selected through discriminant analysis and relationship-test. Lastly, LBMMI was calculated for each sampling point by scoring using core metric elements and five grades were assigned for LBMMI scores using a Beta probability distribution model, with the suitability of LBMMI reviewed by comparing it with TSI_KO. LBMMI developed in this study is expected to appropriately assess ecological integrity of Korean lakes and provide a basis for further research on lake environment conservation.

• Journal of Environmental Science International
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• v.27 no.11
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• pp.1105-1115
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• 2018

The aim of this study was to collect crucial data for the improvement of water quality and ecosystem conservation by analyzing water samples, sediments, benthic macroinvertebrates, and fish in the Seosan reservoir. The average values of water quality parameters from 2001 to 2016 were a chemical oxygen demand of 10 mg/L, total nitrogen of 1.22 mg/L, and total phosphorus of 0.074 mg/L. Cadmium was detected in the range of 0.531-0.748 mg/kg in the reservoir sediment. Fish belonging to 6 families and 9 species were identified in the reservoir. The dominant species were Carassius auratus and Micropterus salmoides. Benthic macroinvertebrates belonging to 22 families and 28 species were identified. The ecological score of the benthic macroinvertebrate community was 15 inside the reservoir (St. 2). Micropterus salmoides, an invasive alien species, was determined to be the subdominant fish species based on the number of captures, and the presence of the invasive species, Sicyos angulatus L. and Paspalum distichum L. was confirmed among the land flora.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.1 no.1
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• pp.84-94
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• 1998

The sources of the pollution on a river are divided into two classes, one the point source and the other non-point source. In raining, especially, the non-point source discharged from paddy, residential area, road ${\cdots}$ etc have correlations with the land use. This study was carried out to find out the model to estimate the quality of water in a river according to the land use. Land use data (Pungse-Myeoun and Kwangduk-Myeoun in Chonan) were produced from Landsat TM (Thematic Mapper) and topographic map. Total nitrogen(TN) and total phosphorus(TP) general indices for the degree of pollution in river were measured during 11 months. Correlations between two variables(Land use and Pollutants(TN, TP)) were explained by the regression coefficient. As a result of this study, we found that among the five types of land use, the residential area, store area and paddy have significant effects upon the quality of water in a river. The results of this study will be applied to pre-estimate the degree of pollution in river broadly and to offer basic data in establishing the land use plan and the concept on the conservation of the river in rural area.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.204-204
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• 2016

Thailand had set the National Water Management Strategy which covered main six areas in the next 12 years, i.e., by priority: (1) water for household, (2) water for agricultural and industrial production, (3) water for flood and drought management, (4) water for quality issue, (5) water from forest conservation and soil erosion protection, (6) water resources management. However due to the climate change impact, there is a question for all strategies is whether to complete this mission under future climate change. If the impact affects our target, we have to clarify how to mitigate or to adapt with it. Vulnerability assessment was conducted under the framework of ADB's (with the parameters of exposure, sensitivity and adaptive capacity) and the assessments were classified into groups due to their different characteristic and the framework of the National Water Management Strategy, i.e., water supply (rural and urban), water for development (agriculture and others), water disasters (floods (flash, overflow), drought, water quality). The assessments identified the parameters concerned and weight factors used for each groups via expert group discussions and by using GIS mapping technology, the vulnerability maps were produced. The maps were verified with present water situation data (floods, drought, water quality). From the analysis result of this water resources management strategy, we found that 30% of all projects face the big impacts, 40% with low impact, and 30% for no impact. It is clear that water-related agencies have to carefully take care approximately 70% of future projects to meet water resources management strategy. It is recommended that additional issues should be addressed to mitigate the impact from climate risk on water resource management of the country, i.e., water resources management under new risk based on development scenarios, relationship with area-based problems, priority definition by viewpoints of risk, vulnerability (impact and occurrence probability in past and future), water management system in emergency case and water reserve system, use of information, knowledge and technology in management, network cooperation and exchange of experiences, knowledge, technique for sustainable development with mitigation and adaptation, education and communication systems in risk, new impact, and emergency-reserve system. These issues will be described and discussed.

• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.3 s.116
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• pp.1-11
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• 2006

This study analyzed characteristics of natural and human environments in Chuncheon's Gongji stream, and suggested nature-friendly planning strategies for self-purification of water quality, biodiversity improvement and conservative waterfront recreation. The environmental analysis included streambed structures, floodplain soils, water quality, vegetation, wildlife, and human facilities. Natural colonization of vegetation for the middle section of the study stream was obstructed by a straightened concrete revetment of baseflow channel, and vehicle movement and concrete parking lots across the floodplain. These human disturbances also deteriorated the naturalness of the stream landscape and limited habitation of bird species. However, natural sedimented wetlands in half of the channel width for the lower section of the stream contributed to a desirable vegetational landscape and greater bird occurrence. Based on BOD measurements, water quality of the stream fell under class $II{\sim}III$ of the stream water-quality standard, but it was worse around sewage outlets due to incomplete sewage collection especially during the dry season. Dominant fish species included typical inhabitants of good water-quality streams that are tolerant of adverse habitat changes. Nature-friendly planning strategies were established based on analysis of the environmental characteristics. They focused on not merely spatial zoning and layout divided into four zones - preservation, partial preservation, conservation and use -, but close-to-nature channel revetment techniques, natural water-purification facilities, biotope diversification, and water-friendly recreation and circulation. Strategies pursued both renewal of stream naturalness and hydraulic stability of streamflow by minimizing transformation of natural channel micro-topography and biotope, and by reflecting natural traces of streambed structures such as revetment scour and sedimentation.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.3
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• pp.30-37
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• 2001

This study was conducted to investigate physicochemical property changes from July 1998 to August 2001 in Mt. Bukhansan National Park. Four water sampling points were selected to measure the quality of stream water in the northeastern part of the Mt. Bukhansan National Park. The results were summarized as follows; In spring, the average pH of stream water was below the first class of the river water quality standard, while it was normal level in summer. The average electrical conductivity was about 2.3~3.3 times higher in downstream water than in upstream water during spring and summer. The contents of anions($Cl^-$, $NO{_3}^-$, $SO{_4}^{2-}$) were about 1.1~7.4 and 0.4~11.4 times higher in downstream than in upstream water, respectively. These results indicate that water quality was poorer in downstream than in upstream water. We suggest that stream water in the Mt. Bukhansan National Park should be protected from impacts of snow melting mineral particles in spring season and human impacts like wastewater of point source in summer season.

• Journal of Korea Water Resources Association
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• v.45 no.9
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• pp.929-941
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• 2012

In recent years, interest in river environment such as riparian landscape, water quality and ecological conservation has been growing with increasing recreation on agricultural river watershed. That caused the increase of necessity of water resources development, one of solutions for the diversification of agricultural water demand and shortages. In this respects, heightening irrigation dam, as a part of the 4-major river restoration project, is necessary to secure not only additional agricultural water but also instream flow for water quality improvement. However, operation plan of irrigation dam still not be clear. In this study, additional storage which secured through heightening irrigation dam was estimated using SWAT model. And instream flow effects on water quality of downstream were evaluated. The findings show that the additional water supply will contribute positively to water quantity and quality of downstream. The results show a 2~10% water quality improvement effect on nutrients, as well as an 1~8% water quantity increasing effect. In particular, additional storage can be effectively supplied from February to April by the reservoir operation. However, maintaining better water quality in irrigation reservoirs is important because the water quality of irrigation reservoirs can be negatively impacts the water quality in downstream of reservoirs.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.198-198
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• 2017

Climate change causes unpredictable and erratic climatic patterns which affects crop production in agriculture and threatens public health. To cope with the challenges of climate change, sustainable and sound growth environment for crop production should be secured. Recent attention has been given to the development of smart irrigation system using sensors and wireless network as a solution to achieve water conservation as well as improvement in crop yield and quality with less water and labor. This study developed the smart irrigation technique for farmlands by monitoring the soil moisture contents and real-time climate condition for decision-making support. Central to this design is micro-controller which monitors the farm condition and controls the distribution of water on the farm. In addition, a series of laboratory studies were conducted to determine the optimal irrigation pattern, one time versus plug time. This smart technique allows farmers to reduce water use, improve the efficiency of irrigation systems, produce more yields and better quality of crops, reduce fertilizer and pesticide application, improve crop uniformity, and prevent soil erosion which eventually reduce the nonpoint source pollution discharge into aquatic-environment.

• Journal of Korea Water Resources Association
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• v.35 no.5
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• pp.525-539
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• 2002

Effects of Yongdam Dam discharge conditions on water quality of the Keum River and Daechung Lake inflow were analyzed for various scenarios using WASP5 water quality model. Three different groups of scenarios were tested: 1) Two different weather conditions; the lowest flow year and the highest flow year since the beginning of Daechung Dam operation in 1981, 2) Fine discharge flow rates; 5.4, 8.9, 12.4, 16.4 ㎥/s and field observed flow during the study period, 3) Three conditions of discharge water quality; first grade, second grade by Korean water quality standard and field observed water quality. Effect of changes in Yongdam Dam discharges was greater for dry year. The increase of discharge from the Yongdam Dam will improve water quality of downstream areas only when the water quality of the discharge is equal or better than that of downstream areas. Field observed water qualify data show that BOD concentrations are lower than first grade level but TN and TP concentrations are exceeding 5th and 3rd grade level in Korean standard, respectively. Considering that nutrient control methods in watershed areas of Yongdam dam are limited, it is expected that nutrient concentrations from Yongdam Dam discharge will be higher than 2nd grade water quality standard level. Therefore, it would be important to develop practical management strategies in the watershed area of Yongdam Dam based on field conditions for conservation of water quality in downstream areas.

• 보존과학연구
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• s.20
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• pp.49-64
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• 1999

According to damage of papers by the chemical cause, papers become to acidify. Among the 3 kinds of method measuring the acidity of paper, one was nondestructive method measuring the surface of the paper by flat type electrode and the others were destructive methods measuring directly by cold water extract method and hot water extract method. In case of the cellulolytic cultural properties, the latter methods were not applied because those methods must bedissociated papers. To measure the paper acidity nondestructively, we investigated the correlation of the nondestructive method and the destructive methods. The conclusions are as follows. 1) In the relationship of the cold water extract method and the hot water extract method, It was indicated that the pH measured by the hot water extract method was high quality printing paper 0.08, rough printing paper 0.13, and Korean paper 0.29 higher than that by the cold water extract method.2) In the relationship of the cold water extract method and the surface measurement method, It showed that the pH value measured by the cold water extract method was high quality printing paper 1.86, rough printing paper 0.80,and Korean paper 0.58 higher than value that by the surface measurement.3) In the relationship of the hot water extract method and the surface measurement method, It showed that the pH value measured by the hot ABSTRACT water extract method was high quality printing paper 1.78, rough printing paper 0.66, and Korean paper 0.29 higher than that by the surface measurement. From the above-mentioned results, the pH value measured by the surface measurement was need to high about 1.78∼1.86 in high quality printing paper, 0.66-0.80 in rough printing paper, and 0.29∼0.58 in Korean paper and the surface measurement with flat type electrode was very available to measure the acidity of Korean papers actually.