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        검색결과 15

        1.
        2001.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        토양이나 암반의 물성을 조사하기 위하여 시추공조사가 흔히 이루어진다. 그러나 시추조사의 결과는 불연속적이고 시추공과 시추공 사이의 물성은 두 시추공의 조사결과를 내삽하여 구할 수 밖 에 없다. 그러나 이러한 내삽법을 이용한 해석은 지반의 수평적 변화가 심하지 않은 경우에만 가능하다. 연약지반의 연속적인 2차원 S파 속도구조를 구하기 위하여 표면파 역산 방법을 사용하였다. 역산 결과를 해석하기 위하여 역산 결과의 해상도를 역산 결과와함께 제시하였다.
        4,000원
        2.
        2000.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        어류군집을 이용한 생물보전지수(Index of Biological Integrity, IBI)와 서식지 평가지수 (qoalitativeHabitatEvaluationlndex, QHEI)를 적용하여 금호강의 수서 생태계를 평가하였다. 총체적으로 금호강의 IBI값은 13-37 범위에 있었으며, 연 평균값은 23(n=25, Std. error=1.16)으로서 Karr(1981) 와 U.S. EPA (1993) 기준에 따르면 "Poor" 또는 "Very Po
        4,300원
        5.
        1988.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to understand the variation characteristics of suspended solid in the Keum River Estuary. Water sampling was carried out regularly with response to the tidal cycle from September, 1986 to August, 1987. Analyzed or observed items were sea water temperature, salinity, TS, TDS, TSS, VSS, FSS. and also the relationships between wind velocity, precipitation, tidal cycle and TSS were investigated. It is found that the sea water temperature is the lowest in January(2.5℃)and the highest in August(24.4℃), and increases toward upstream in summer and vice versa in winter. Salinity is the lowest in August (13.6‰) and the highest in December(20.3‰), and the annual mean value shows 13.6‰. TS and TDS are firmly related with the variation of salinity, thus, high in spring and low in summer. The annual mean values of TSS in 199.8(65.3∼454.5)㎎/ℓ, highest in March 308.2(67.5∼792. 3)㎎/ℓ and lowest in June 36.8(10.9∼200.0)㎎/ℓ. The annual mean values of VSS is 22.0㎎/ℓ, its variation tendency is similar to that of TSS. The annual mean value of VSS /TSS ratio is 13.9(6.8∼20.2)%, which are not high level compared with those of polluted sea areas. This ratio is high in summer(24.1%) and low in autumn(13.3%), and increases toward the downstream direction. It is also revealed that TSS shows a positive correlation with the wind velocity(r=0.59), and a negative with the precipitation in the Keum River basin(r=-0.64). TSS concentration is primarily subjected to the tidal range and the freshwater discharge and also related to the resuspension of bottom sediments by the action of wind force or wind waves. The dilution rate is strongly subjected to the seasonal variation of the freshwater discharge, therefore, TSS concentration shows low in summer and high in winter. Under low discharge condition in spring, autumn and winter, TSS, VSS are high level in spring tide compared with those in neap tide : under high discharge condition in summer, these values are reversed that is, TSS is higher in neap tide than in spring tide.
        5,500원
        6.
        1988.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The structure and change of the salinity front formed by the outflow of Keum River into the adjacent sea is investigated through the analysis of some possible data. The outflow of the river has no peculiar direction and controlled by the various factors. The analysis of data which are obtained at March and October show that at March, the salinity front is weakened as compared with October. The outflow pattern is not uniform but varies significantly with time period less than one week.
        4,000원
        7.
        2015.06 KCI 등재 서비스 종료(열람 제한)
        The objectives of study were to evaluate fish species compositions of trophic guilds and tolerance guilds and apply ecological fish assessment (EFA) models to Bekjae Weir, Keum-River Watershed. The EFA models were Stream Index of Biological Integrity (SIBI) used frequently for running water and Lentic Ecosystem Health Assessment (LEHA) used for assessments of stagnant water. The region of Bekjae Weir as a "four major river project" was originally a lotic ecosystem before the weir construction (2010, BWC) but became more like lentic-lotic hybrid system after the construction (2011, AWC). In the analysis of species composition and ecological bioindicator (fish), fish species with a preference of running water showed significant decreases (p < 0.05), whereas the species with a preference of stagnant water showed significant increases (p < 0.05). After the weir construction, relative abundances of tolerant species increased, and the proportion of insectivores decreased. This phenomenon indicated the changes of biotic compositions in the system by the weir construction. Applications of SIBI and LEHA models to the system showed that the two model values decreased at the same time after the weir construction (AWC), and the region became more like lentic-lotic hybrid system, indicating the degradation of ecosystem health. The model values of SIBI were 19 and 16, respectively, in the BWC and AWC, and the health conditions were both "C-rank". In the mean time, the LEHA model analysis showed that the values was 28 in the BWC and 24 in the AWC, thus the health was turned to be "B-Rank" in the BWC and "C-Rank" in the AWC. indicating a degradation of ecological heath after the weir construction.
        8.
        2007.04 KCI 등재 서비스 종료(열람 제한)
        본 연구는 금강하류 철새조망대 일대의 해안식물과 내륙에 분포하는 식물 및 경작지 주변의 관속식물을 조사한 후 식물구계학적 특정식물종과 귀화식물 등을 조사하여 다음과 같은 결론을 도출하였다. 본 대상지인 금강하류 일대의 관속식물상을 조사한 결과, 74과 179속 211종 24변종 3품종으로 총 238종류가 확인되었다. 이중 목본식물은 총 238종류 중 60종류(25.2%), 초본식물은 178종류(74.8%)로 분석되었다. 또한, 양치식물은 4과 4속 4종류, 나자식물은 2과 2속 3종류, 피자식물은 68과 173속 231종류가 확인되었다. 한국특산식물에는 은사시나무와 개나리가 확인되었으며, 식물구계학적 특정식물종에는 III등급에 참오굴잎버들, I등급에는 물오리나무, 굴참나무, 예덕나무, 개질경이, 뚜껑덩굴, 보풀 등의 6종류가 확인되었다. 귀화식물은 14과 35속 40종 2변종으로 총 42종류와 귀화율은 17.6%로 분석되었다. 귀화식물 중 생태계교란야생식물인 돼지풀(Ambrosia artemisiifolia var. elatior)은 꽃가루 알레르기로 인한 인체에 피해를 주기 때문에 지속적인 관리와 대책이 요망된다.
        9.
        2002.12 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to evaluate water quality in the Keum River using multivariate analysis. The analysis data in Keum river made use of surveyed data by the ministry of environment from January 1994 to December 2001. Thirteen water quality parameter were determined on each sample. The results was summarized as follow; Water quality in the Keum River could be explained up to 71.39% by four factors which were included in loading of organic matter and nutrients by the tributaries (32.88%), seasonal variation (16.09%), loading of pathogenic bacteria by domestic sewage of Gapcheon (13.39%) and internal metabolism in estuary as lakes(9.03%). For spatial variation of factor score, four group was classified by each factor characterization. Station 1 and 2 was influenced by Daechung dam, station 3 was affected by domestic sewage of Gapcheon, station 10~12 was affected by estuary dyke and the rest station. The result of cluster analysis by station was classified into four group that has different water quality characteristics. In monthly cluster analysis, three group was classified according to seasonal characteristic. Also, in yearly cluster analysis, three group was classified. It is necessary to control the pollutant loadings by Gapcheon inflow domestic sewage in Daejeon city for the sake of water quality management of Keum river.
        10.
        2002.10 KCI 등재 서비스 종료(열람 제한)
        용담댐의 건설에 따른 방류조건의 변화가 대청호의 유입수질에 미치는 영향을 파악하기 위하여 WASP5 모델을 이용하여 BOD, 총인 그리고 총질소 농도를 예측하였다. 수질 예측 시나리오는 크게 다음과 같이 세 가지로 구분하였다; 첫째, 금강의 유량이 대청댐의 운영이 시작된 이래 최대 갈수년(1994)과 최대 풍수년(1987)과 같다고 보는 두 가지 조건, 둘째 용담댐에서 방류되는 유량을 연구기간 중(1998년) 실측된 유량과 같다고 보는 경우와 용담댐 방
        11.
        2002.06 KCI 등재 서비스 종료(열람 제한)
        This study was to evaluate the impact of river runoff and salt intrusion by tide on nutrient balance of estuary during a complete tidal cycle. 24 hours time series survey was carried out during a spring tide July 2001 on a tidal estuary in the Keum river. Three stations(A,B,C) were set along a transect line of about 10km, which linked the lower part of estuary dyke to the subtidal zone. Surface water was sampled simultaneously at each station every hours for the determination of nutrients. Water temperature, pH and dissolved oxygen were measured in situ. Riverine input of silicate and nitrate during ebb tide significantly increased the concentration of all stations. Conversely, during high tide, nutrient concentration were lowered by the mixing of fresh water with sea water. Ammonium nitrogen concentration were higher at intertidal zone(Stn.B) due to sewage inflow to Kyeongpo stream and ammonium release under anaerobic conditions. Also, these results was discussed as a biological component that influences the processes of nutrient regeneration within the estuary. Best correlations were found at lower part of estuary dyke(Stn.A) for salinity against DIN(Y=0.121 Sal.+4.97, r2=0.956) and silicate(Y=0.040 Sal.+2.62, r2=0.785). But no significant correlation was found between salinity and ammonium. Unbalanced elemental ratio(N/P, Si/N and Si/P) depended significantly on the import of nutrients (silicate & nitrate nitrogen) from river and stream. The effect of the tidal cycle and river runoff is important that in determining the extend of the variations in nutrient concentrations at all station.
        12.
        2001.04 KCI 등재 서비스 종료(열람 제한)
        The Keum river is one of the important river in Korea and has a drainage area of 9,873 ㎦. The Keum river is deepening pollution state due to development of the lower city and construction of a industrial complex. The water quality of the Keum river come to eutrophication state and belong to Ⅲ grade of water quality standard. The concentration BOD in river is affected by the organic loading from a tributary and the algae biomass that largely happen to under eutrophication state. In the eutrophic water mass such as the Keum river, the autochthonous BOD was very important part for making a decision of water quality management, because it was accounted for majority of the total BOD. The purpose of this study was to survey the characteristics of water quality in summer and to estimate reaction coefficient. Also, we studied to correlationship between chlorophyll a and BOD(COD) for estimation of the autochthonous BOD. The correlationship between chlorophyll a and BOD(COD) were obtained through the culture experiment of phytoplankton in the laboratory. The results of this study may be summarized as follows ; The characteristics of water quality in summer were belong to Ⅲ∼Ⅳgrade of water quality standard as BOD and nutritive condition is very high. The BOD, ammonia nitrogen and phosphate loadings in Miho stream which inflowing untreated sewage from Chungju city was occupied with 64.07%, 26.36%, 46.08%, respectively. Maximum nutrient uptake (Vmax) was 0.4400 μM/hr as substrate of ammonia nitrogen, 0.1652 μM/hr as substrate of phosphate. Maximum specific growth rate (μmax) was 1.2525 hr-1 as substrate of ammonia nitrogen, 1.5177 hr-1 as substrate of phosphate. The correlation coefficient between chlorophyll a and BOD by the culture experiment were found to be 0.911∼0.935 and 0.942∼0.947 in the case adding nutrient and no adding nutrient, respectively. The correlation coefficient between chlorophyll a and COD through the culture experiment were found to be 0.918∼0.977 and 0.880∼0.931 in the case adding nutrient and no adding nutrient, respectively. The autochthonous BOD(COD) was estimated to the relationship between BOD(COD) and chlorophyll a. The regression equation were found to be autochthonous BOD=(0.045∼0.073)×chlorophyll a and autochthonous COD=(0.137∼0.182)×chlorophyll a.
        13.
        2001.02 KCI 등재 서비스 종료(열람 제한)
        The Keum river has been utilized for drinking water supply of several city including Kunsan city and is deepening pollution state due to numerous municipal and industrial discharges. The concentration BOD in river is affected by the organic loading from a tributary and the algae biomass that largely happen to under eutrophication state. In the eutrophic water mass such as the Keum river, the autochthonous BOD was very important part for making a decision of water quality management, because it was accounted for majority of the total BOD. The predict of water quality has important meaning for management of water quality pollution of the Keum river. The purpose of this study will manage and predict water quality of the Keum river using QUAL-2E model considering the autochthonous BOD. The estimation of autochthonous BOD represented that the relationship between BOD and chlorophyll a. The regression equation was shown to be autochthonous BOD=β5×chlorophyll a. The results of this study may be summarized as followed; The QUAL-2E model was calibrated with the data surveyed in the field of the study area in June, 1998. The calculated value by QUAL-2E model are in good agree to measured value within relative error of 7.80∼20.33%. Especially, in the case of the considering autochthonous BOD, the calculated value of BOD were fairly good coincided with the observed values within relative error of 15%. But the case of not considering autochthonous BOD, relative error of BOD was shown to be 43.2%. In order to attain Ⅱ grade of water quality standard in Puyo station which has a intake facility of water supply, we reduced to the pollutants loading of tributaries. In the case of removed 100% BOD of tributaries, the BOD of Puyo station was 4.07㎎/ℓ, belong to Ⅲ grade of water quality standard. But in the case of removed 88% nutrient of tributaries, it was satisfied to Ⅱ grade of water quality standard as below 3㎎/ℓof BOD. For estimation of autochthonous BOD in Keum river, we are performed simulating in accordance with reduction of nutrient load(50∼100%) under conditions removal 90% organic load. Occupancy of autochthonous BOD according to nutrient loading reductions were varied from 25.97∼79.51%. Occupancy of autochthonous BOD was shown to be a tendency to increasing in accordance with reduction of nutrient loading. Showing the above results, the nutrient that one of the growing factor of algae was important role in decision of BOD in the Keum river. For the water quality management of the Keum river, therefore, it is necessary to considering autochthonous BOD and to construction of advanced sewage treatment plant for nutrient removal.
        14.
        1999.04 KCI 등재 서비스 종료(열람 제한)
        To investigate the water quality characteristics and eutrophication of the Keum River, survey were conducted on samples collected from 6 stations in Aug. and Oct. in 1995 and Jan. and May in 1996. The results were summarized as follows ; Concentration of pollutants were in the range of 1.74∼6.35(mean 3.81)㎎/ℓ for BOD and 1.98∼8.21(5.14)㎎/ℓ for COD and 1.46∼51.94(18.52) g/ℓ for TSS. Water quality were evaluate to be 2∼3 grade of station 1 and other stations were 3∼4 grade of water quality criteria. The concentration of nutrients were in the range of 55.2∼735.3(309.3)㎍-at/ℓ for Dissolved inorganic nitrogen(DIN) and 0.06∼6.03(2.80)㎍-at/ℓ for dissolved inorganic phosphate(DIP). Nutrient concentrations in Keum River were usually high and the DIN/DIP ratio ranged from 72 to 2648. The concentration of chlorophyll-a was in the range of 1.1∼143.7(44.3)㎎/㎥. Chlorophyll-a concentration were high 10㎎/㎥ except station 1, which is the value of eutrophication criteria by EPA. Correlations between nutrients and chlorophlly-a were not significant. According to eutrophication evaluation, Keum river was equivalent to the eutrophic state.
        15.
        1998.10 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to evaluate water quality in the Keum River estuary using principal component analysis. The results was summarized as follow; Water quality in the Keum River estuary could be explained up to 70.40% by three factors which were included in the inffluent loading by the Keum River and Kyungpo cheon(38.99%), seasonal variation and organic matter pollution(19.05%), sediment resuspension and internal metabolism(12.35%). For spatial variation of factor score, artificial pollutant loading is highest at st.1, below Keum River barrage, and decreases toward the outer sea. For annual variation of factor score, factor 1 was highly related to artificial pollutant loading, and it was greatly increased in 1994. Also, organic matter pollution, sediment resuspension and internal metabolism were increased to every year. is necessary to control the nutrient loading by Keum river and Kyongpo cheon for Water quality management of estuary.