• 한국물환경학회지
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• 제31권6호
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• pp.637-643
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• 2015

This study has been carried out to provide the basic data obtained from the evaluation of the variation of water quality around the Chudong intake tower in Daechung resevoir, which may be able to help the establishment of a pure water supply policy. Five sites around the Chudong intake tower were selected, and the average data for recent ten years(from year 2004 to year 2013) were analysed. The average water quality around Chudong intake tower are as followed; pH 7.5, DO 8.7 mg/L, BOD 1.0 mg/L, COD 3.0 mg/L, SS 3.0 mg/L, TN 1.495 mg/L, TP 0.017 mg/L, and Chlorophyll-a 6.5 mg/m³ were matched the good class by comparing with the living environment standard of reservoir. COD values of higher than 3.0 mg/L after July were likely due to non-point pollutants and algae outbreak during rainy summer season. Total phosphorus rose sharply in the summer season, and then algae watch was issued consistently for average 40 days. Total nitrogen to total phosphorus ratio was average 90, and it is important to control the inflow phosphrous from small stream for proper management to block an algae growth according to eutrophication. It was recommended to operate the algae removing boats around intake tower from July to October, and was required advanced water treatment processes to remove NBD COD and bad odor and taste due to algae growth.

• 한국물환경학회지
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• 제30권4호
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• pp.377-385
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• 2014

To study the fluctuations and relationship in climate change, environmental factors and cyanobacteria communities, we investigated Chudong station of the Daechung reservoir. The average annual temperature showed the maximum value ($13.9^{\circ}C$) from 1994, showed a gradually increasing pattern from 1969 to 2010 in the Daechung reservoir. The number of days with temperatures over $20^{\circ}C$, minimum temperature of the year and average temperature of the winter season patterns also showed a significant increase. The long-time changed in the annual precipitation were not showed a significant variation. The water temperature record comparatively high value in summer, declined in winter. At all period, the phytoplankton were highest biomass in July 2000, and then, showed comparative higher biomass in the summer months. Cyanobacteria taxa were also showed more than 50%. Emergence of cyanobacteria also appeared in November 2007, were prolonged emergence. The dominant genera of taxa were the dominant sphere (Microcystis spp.) until early 2000. After that, the dominant species were the dominant linear (Aphanizomenon spp., Anabaena spp.). Cyanobacteria were the most correlated with water temperature (r = 0.341, p<0.01) and phosphate concentration (r = 0.355, p<0.01).

• 대한환경공학회지
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• 제37권5호
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• pp.277-284
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• 2015

대청호의 추소수역과 추동수역에서 채취한 퇴적물의 오염도를 평가하기 위하여, 퇴적물의 입도, 유기물 및 영양염류의 농도와 인의 성상별 분석을 수행하였다. 소옥천의 영향을 받는 추소수역의 상류에 비해 추소수역에서 본류로 유입되는 지점과 추동수역의 퇴적물에서 실트 크기 입자의 평균 비율이 92%로 매우 높았다. 추소수역과 추동수역에서 퇴적물 중 총인의 농도는 각각 999 (${\pm}98$)과 1,123 (${\pm}119$) mg/kg sediment로 추동수역에서 상대적으로 높았다. 퇴적물 중 인의 성상분석 결과 외부 기원성 인보다 환경 조건 변화에 의해 쉽게 용출이 되는 것으로 알려진 내부 기원성 인의 비율이 높게 측정되어 이들 지점의 부영양화에 내부부하가 중요한 것으로 판단되었다. 퇴적물 중 총질소의 농도는 모든 시료에서 환경부의 하천 호소 퇴적물 오염평가 기준인 5,600 mg/kg sediment를 초과하여, 퇴적물의 총질소 오염도가 심각한 것으로 판단되었다. 이러한 결과로부터 대청호의 수질 개선을 위해 퇴적물에 대한 관리 대책이 필요한 것으로 판단된다.

• 환경위생공학
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• 제15권1호
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• pp.109-115
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• 2000

This study was designed to investigate the quality of the simplified water supplies by regional groups in Uijoungbu. For this objective physicochemistric and microbiological experiment were performed. Simplified water in Uijoungbu(Howondong Darakwon, Singokdong Chudong, Songsandong Mangadae, Songsandong Gacbawe, Songsandong Gusungmal, Songsandong Baebul, Ganeung3dong) tested by this study physicochemistric elements suited the test. However, Songsandong Mangadae exceeded the minimum level suggested as $NO_3-N(10mg/{\ell})$. The population of general bacteria were exceeded the minimum level suggested as drinkable water(less than $100CFU/m{\ell}$). Some simplified water in Uijoungbu were proven to be contaminated.

• 한국환경복원기술학회지
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• 제21권2호
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• pp.65-75
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• 2018

This study analyzes the characteristics of the urban landscape changes as a result of the introduction of private parks among the long-term uncollected urban planning facilities and enables the analysis of the characteristics of the urban landscape changes as a result of the introduction of private parks, and applied to the private park projects. The DSM with its building was established for the quantitative landscape analysis to examine the view ratio using the stacked visible analysis. The analysis showed that Jikdong Park had a high frequency of view from downtown to green due to its location, and that the development project of a private park on park and town boundaries significantly lowered the view ratio. This implies a large degree of damage to the landscape by development projects provided protection of the view as a natural landscape is of value. Chudong Park also saw its view ratio of views from downtown to the hills green area of Chudong Park was much lower than that of Jikdong Park. And it was confirmed that the ratio of view changes due to development projects was small compared to that of Jikdong Park. In other words, although Jikdong Park and Chu-dong Park were developed in a similar scale in terms of the ratio of views, they were subject to significant damage due to their location characteristics. It is also meaningful to note that the degree of change in the landscape resulting from development projects that could not be found in the assessment or review of the existing Landscape Impact. As private parks are introduced in the urban green belt, apartment development is being pushed for at the edge of the green belt. This study is meaningful in that it is derived based on the calculation that the survey results are derived based on the changes in the views on green areas that urban residents may experience as the private park project is carried out, and it should be introduced based on the calculation of the private parks.

• 보존과학회지
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• 제24권
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• pp.13-22
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• 2008

서천 추동리 문화유적내 토과목관묘에서 출토된 숯과 인근의 기와가마에서 연료로 사용되었던 나무의 숯을 채취하여 수종을 식별하고 각각의 흡습성과 가스 흡착성을 비교하였다. 총 23점의 숯 시료에 대해서 수종을 식별한 결과 토광목관묘에서 출토된 12점의 숯은 모두 활엽수 숯으로 9점이 참나무속의 상수리나무아속 계통, 3점이 팽나무속 숯인 것으로 밝혀졌다. 한편 기와가마에서 출토된 11점의 숯은 모두 침엽수로 경송류의 소나무류인 것으로 식별되었다. 출토 숯의 물리적 성질을 조사한 결과 토광목관묘의 활엽수 숯이 기와가마의 소나무류 숯보다 높은 흡습성을 나타냈으며 에틸렌 가스 흡착 시험에서도 상수리나무아속 숯이 소나무류 숯보다 높은 가스 흡착성을 보였다. 토광목관묘 유구에 활엽수 숯을 사용한 이유는 침엽수 숯에 비하여 활엽수 숯이 미세 세공이 많고 비표면적이 넓어 수분과 가스 흡착력이 우수하여 묘광 내에 보다 양질의 매장 환경을 조성할 수 있기 때문으로 판단된다. 한편, 기와가마에서 소나무류를 연료로 사용한 이유는 비중이 작아 재질이 연하여 연소가 잘되고 특히 재내에 다량의 수지(송진)를 함유하고 있어 발열량이 높고 비교적 화력 조절이 용이했기 때문으로 판단된다.

• 생태와환경
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• 제43권4호
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• pp.492-502
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• 2010

The study objects were to analyze long-term and seasonal variations of nutrients (N, P), suspended solids, N:P ratios, algal chlorophyll, and trophic state along with general water quality parameters in four sampling sites including two intake tower sites supplying drinking water in Daechung Reservoir. For the analysis, we used water quality long-term data sampled during 1998~2007 by the Ministry of Environment, Korea. Interannual and seasonal trends in inflow and discharge near the intake tower facilities over the ten years were directly influenced by rainfall pattern. The distinct difference between wet year (2003) and dry year (2001) produced marked differences in water temperature, pH, dissolved oxygen, organic matter contents, nutrients, and these variables influenced algal biomass and trophic state. Values of TP varied depending on the year and locations sampled, but monthly mean TP always peaked during July~August when river inflow and precipitation were maxima. In contrast, TN varied little compared to TP, indicating lower influence by seasonal flow compared to phosphorus. The number of E. coli were highest in Site 2 (Chudong intake tower) and varied largely, whereas at other sites, the numbers were low and low variations. Contents of chlorophyll-${\alpha}$ (CHL), as an estimation of primary productivity, varied largely depending on the year and season. The maximum of CHL occurred at Muneu intake tower (S4) during 2006 when the precipitation and inflow were lowest. In contrast, another CHL peak was observed in Site 2 (Chudong intake tower) in 2006 when one of the largest typoons (Ewinia) occurred and river runoff were maximum. So the CHL maxima were associated with both wet year (high flow, high nutrient supply) and dry year (low flow, nutrient supply by littoral zone). Such conditions influenced trophic states, based on Trophic State Index of nutrients and CHL. Based on all analyses, we can provide some clues for management and protection strategies of two intake tower sites.

• 상하수도학회지
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• 제35권6호
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• pp.507-516
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• 2021

In this study, the machine learning which has been widely used in prediction algorithms recently was used. the research point was the CD(chudong) point which was a representative point of Daecheong Lake. Chlorophyll-a(Chl-a) concentration was used as a target variable for algae prediction. to predict the Chl-a concentration, a data set of water quality and quantity factors was consisted. we performed algorithms about random forest and gradient boosting with Python. to perform the algorithms, at first the correlation analysis between Chl-a and water quality and quantity data was studied. we extracted ten factors of high importance for water quality and quantity data. as a result of the algorithm performance index, the gradient boosting showed that RMSE was 2.72 mg/m³ and MSE was 7.40 mg/m³ and R² was 0.66. as a result of the residual analysis, the analysis result of gradient boosting was excellent. as a result of the algorithm execution, the gradient boosting algorithm was excellent. the gradient boosting algorithm was also excellent with 2.44 mg/m³ of RMSE in the machine learning hyperparameter adjustment result.

• 한국환경복원기술학회지
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• 제19권6호
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• pp.111-121
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• 2016

This study was carried out to assess the riparian vegetation health in the fluctuation area and vicinity of reservoirs. The results of this study could be a basic data to improve the ecological function and establish green-network of waterside ecosystem. The study site is Daecheong lake reservoirs which the representative landscape of Geum river and with great number of visitors near metropolitan city. The 6 survey plots of 2 survey area were selected, survey area 1 had 4 survey plots and survey area 2 had 2 survey plots, and to compare the study results 4 control plots were selected in Gyeongcheon reservoir. The main dominant specie of survey sites was Salix koreensis in tree and subtree layer, were Salix koreensis and Salix glandulosa. in shrub layer. 2 survey plots of Samjeongdong and Kyeongcheon reservoir were assessed as 'Good', 2 survey plots of chudong were assessed as 'Fair' in vegetation health assessment. In the fluctuation area from flood water level to low water level, 58 populations of Salix koreensis were found in survey sites and Salix koreensis, Salix glandulosa and Acer tataricum subsp. ginale were found in control sites. The most adequate species at the condition affected by inundation impacts would be Salix koreensis and Salix glandulosa was more healthy at the area less affected by inundation. This study was carried out the vegetation health assessment on Daecheong reservoir which has been advanced natural succession for more than 30 years after the construction. Further, it should carry continuously out the research on the planting model of the waterside ecosystem for ecological restoration.

• 한국미생물·생명공학회지
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• 제27권4호
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• pp.273-277
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• 1999

From each sediments collected at Chudong(static) and Hoenam(streaming) site of Lake Daechung on May 18(before rainy season) and on August 24 in 1998(after rainy season), different strains of Actinomycetes were isolated and identified to genus level. For comparison, the genus diversity of Actinomycetes in control soils such as grass land around lake, lake shore, and shallow(5-10cm) lake was also investigated. In consequence, the isolation of Streptomyces from the sediments of Lake Daechung was the most copious(41 strains) at the streaming site before rainy season and the least(27 strains) at the static site before rainy season, which were 2.4- and 1.6-fold larger than the average(17 strains) of control soils, respectively. In addition, the isolation of rare Actinomycetes from the sediments of Lake Daechung was the most copious(23 strains) at the streaming site before rainy season and the least(12 strains) at the static site after rainy season, which were 3.2-and 1.6-fold larger than the average(17 strain) of controls, respectively. Therefore, it is considered that lake sediments exhibit higher diversity of Streptomycete as well as rare Actinomycetes than general soils, and thereby can be utilized as useful sources to isolate diverse Actinomycetes.