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1996년과 1997년도 2년동안 1월부터 12월까지의 영남지역의 5개소를 선정하여 실험하였다. 본 실험에서 조사한 지역은 낙동강 유로연장 521.1km중 57%에 해당하는 경상북도 유로구간 298.1km로서 상류지역 3개소(안동, 상주, 구미), 중류지역 2개소(왜관, 고령)로 총 5개소에 대해 실시하여 낙동강의 수질오염 특성을 알아보고 낙동강 수질 개선 및 장례에 예상되는 수질악화에 대비한 물 관리의 기초자료로서 활용하고자 본연구를 시도하였으며 그 결과는 아래와 같다. 1. 낙동강의 조사지역 5개소의 pH는 공히 6.5~8.6 정도를 나타내었다. 2. 용존산소량(DO), 화학적 산소요구량(COD), 생물학적 산소요구량(BOD)은 여름철에 낮아지고 겨울철에 높아지는 현상이 관찰되었다. 3. 부유물질(SS)은 여름철에 급격히 높아지는 현상이 관찰되었다. 4. 총인과 총질소는 조류가 번식하여 부영양화를 일으킬 만큼 높은 수준은 관찰되지 않았으나 상당한 수준의 양이 관찰되었다. 5. -N와 -N는 비교적 높은 수준이 관찰되었다.

The purpose of this survey was to investigate the regional and seasonal characteristics of a water system and to obtain basic information of a water system at Andong bridge, Nakdan bridge, Kangjung, Waekwan bridge and Koryung bridge along Nakdong River. We surveyed the water quality in the Nakdong River for 2 years from Jan. 1996 to Dec. 1997. The results summarized were follows; 1) The pH in the Nakdong River on the basic of 2 years average were 6.5-8.6. 2) The DO, the COD and the BOD were low level in summer and high level in winter, respectively. 3) The suspended solids(SS) contents was high especially in summer. 4) The T-P and the T-N contents were higher than the lower level of nitrogen and phosphorous for algae growth and the contents were high especially in winter. 5) The -N and -N were also observed to be quite high.

도시지역 하천으로 직접 배출되는 교량도로 유출수의 수질과 입자의 유출특성을 파악하고자 강우 유출수 시료를 분석하였다. 도로유출수에는 미세입자물질, 중금속, 유기물질 성분을 다량 함유하고 있다. 교통량이 많은 4차선과 6차선 도로 4개 지점을 대상으로 총 7회의 강우 시료를 채수하여 분석하였다. 분석항목은 유량, COD, SS, T-N, T-P, $PO_4-P$ 그리고 입경분포이다. 도로유출수 수질농도 범위는 SS $35\sim2,390$ mg/L, COD $40\sim1,274$ mg/L, T-N $0.03\sim21.25$ mg/L, T-P $0.05\sim4.58$ mg/L으로 조사되었다. 교량도로유출수의 입경을 분석한 결과 $D_{Mean}$값의 범위는 $4.75\sim14.05{\mu}m$이고 $D_{90}$입경의 범위는 $17.33\sim58.15{\mu}m$로 분석되었다.

Water quality constituents, and particle size distributions were characterized in urban bridge road runoff, Bridge road runoff contains significant loads of micro-particles, heavy metals and organic constituents. Bridge road runoff was monitored on four sites of four and six lanes bridge road areas along with traffic volume. A total seven storm events were monitored to characterize the bridge road runoff. The quantity of road runoff and quality constituents, including chemical oxygen demand(COD), suspended solids(SS), total nitrogen(T-N), ortho-phosphorus$(PO_4-P)$, total phosphorus(T-P), and particle size distribution were analyzed. The results indicate that the concentrations of SS, COD, T-N and T-P ranges were $35\sim2,390$ mg/L, $40\sim1,274$ mg/L, $0.03\sim21.25$ mg/L, and $0.05\sim4.58$ mg/L, respectively. And the results showed that the mean range of particle size and $D_{90}$ for bridge road runoff were $4.75\sim14.05{\mu}m$ and $17.33\sim58.15{\mu}m$, respectively.

하상 굴착 공사는 골재 채취, 토사준설, 교량 건설 또는 하천을 횡단하여 매설하는 관로 공사 등 여러 가지 경우에 이루어지고 있다. 이러한 하상 굴착 공사 과정에서 발생하는 다량의 부유물질(SS)은 수질을 오염시키며 환경에 악영향을 미치게 된다. 본 논문에서는 현장 여건상 정교한 수치해석모형을 적용할 수 없는 경우에, 2차원 이송-확산 모형을 단순화하여 유도한 Fick 확산 모형에 의하여 부유물질의 농도를 산정하고 오탁 방지 시설 설치에 따른 부유물질 농도의 저감 효과를 평가하는 방법을 검토하였다. 강원도 동해시에 위치한 전천의 송유관로 매설공사를 대상으로, Fick 확산 모형이 하상 굴착으로부터 발생하는 부유물질의 농도 산정과 오탁방지막의 설치에 따른 오염 저감 효과를 사전에 예비적으로 평가하는 실무적인 방법이 될 수 있음을 제시하였다.

Excavation works on stream beds have been done for various reasons including aggregate collection, sediment dredging, bridge constructions, or laying pipes under the ground. These activities may cause significant loadings of SS (suspended solids) resulting in water pollution and other detrimental effects to the surrounding environment. This research investigates application potential of a fickian diffustion model, derived from two dimensional advection-diffusion equation through some simplifying assumptions, as a planning tool for the estimation of SS loadings from excavation works and evaluation fo pollution prevention measures in case that sophisticated numerical simulation models are not applicable due to various practical reasons. Through a case study of the Juncheon stream in the Donghae City on the Kangwondo Province, this study demonstrates applicability of the fickian diffustion model as a practical method for the preliminary estimation of Ss loadings from excavation works and evaluation of performance of fabrics made of synthetic fiber for the reduction of downstream SS concentration with deficient field data.

강릉 주문진항 입구로 유입되는 신리천 유역의 수질을 2003년 4월 2일부터 10월 29일까지 2주 간격으로 관측하였으며, 미계측 유역의 유량추정에 이용되는 TANK 모형을 이용하여 신리천의 하천수량을 일별로 산정하였다. 관측된 수질자료의 지점별$.$시기별 변화양상을 분석하였으며, 유역의 강수량과 하천수량과의 상관관계를 분석하였다. 분석결과, 신리하교 지점의 BOD 농도와 강우량과는 상관계수 0.75로 높은 상관성을 보였으며, SS농도와 2일 선행강우량과는 상관계수 0.36으로 약한 상관성을 보였다. COD, TN, TP 항목의 농도는 강수량, 하천유량과는 전혀 상관성이 없는 것으로 파악되었다. 따라서, 본 연구에서 제시한 BOD 항목의 유역 오염부하량은 신뢰할 만한 수준이며, SS 항목의 오염부하량도 정확도가 다소 감소하지만 전체적인 오염부하량 변화양상은 반영하는 것으로 평가되었다. 반면, COD, TN, TP 항목의 유역 오염부하량 추정결과는 평균 오염부하량 수치정도로 활용 할 수 있으나, 시기적인 변화양상을 파악하기 위해서는 인위적인 요소 및 토지이용 양상 등을 고려한 연구가 필요하다.

Water qualities (WQ) were measured biweekly from April 2nd to October 29th, 2003 in Sillicheon flowing into the entrance of Jumunjin Harbour and daily water quantities (river discharges) were estimated by the TANK model which has been widely used to compute the runoff discharges in the ungauged watersheds. The spatial and temporal change patterns of the measured WQs were analysed in detail and the correlation between rainfall - WQ and river discharge - WQ were also analysed. From this results, it is found that the correlation coefficient between BOD concentration and rainfall is 0.75 and between the SS concentration and 2-days river discharge is 0.36. The correlation between the COD, TN, TP in the station of Silli Lower Bridge and rainfall runoff quantity was analysed as un-correlated items. As a consequence, the estimated BOD and SS pollutants loads are reliable and show good change patterns even though the accuracy of SS pollutants load is slightly low. The estimated COD, TN and TP pollutants loads, however, can be used only as the reference or averaged values. In order to analyse more accurately the temporal change patterns of these items, more-detailed researches considering the artificial effects and landuse patterns are highly required.

무심천의 오염실태와 그 방지책을 강구하기 위하여 1989년 8월과 9월 2회에 걸쳐 채수한 수질을 분석하여 다음과 같은 결과를 얻었다. 1. 8, 9월의 주간 무심천 수온은 미생물과 조류의 생육에 지장이 없는 것으로 보이는25.8-$30.8^{\circ}C$로써 자정능력이 있는 것으로 판단되었다. 2. 동 기간중 무심천수의 pH는 St 14를 제외하고는 6.5-8.5 범위이었다. 3. St 18(분뇨처리장 배수구와 무심천의 합류지점)에서 9월에 DO가 0.7 ppm까지 내려가는 현상이 관찰되었다. 4. St 18에서 BOD가 최고 62.1 ppm으로써 분뇨 처리장 방류수의 BOD 허용치인 40 ppm 을 크게 초과하였다. 또한 SS도 8, 9월에 각각 200과 520ppm으로써 허용치인 70 ppm을 3-7배 초과 하였다. 5. St 18에서 9월중에 $NH_3-N$이 46.2 ppm이나 되는 것은 분뇨로 크게 오염되어 있음을 말해 준다. 6. 9월중 사직동 하수의 BOD 부하량은 약 0.306ton/day이었다. 7. 무심천 본류보다 무심천으로 유입되는 지천과 가정하수구 및 분뇨처리장 방류수에서 오염도가 훨씬 높았다. 8. St 12(사직동 하수)의 2시간별로 채수한 시료에서 오염물질의 부하량이 인근 주민의 생활주기와 밀접한 관계가 있음을 알 수 있었다. 9. 1979년 무심천 수질 분석 결과와 비교해 볼 때 영운동 취수장(St 9)에서는 큰 차이가 없었으나 사직동 하수(청주대교 밑, St 12)와 제2운천교(St 15)에서는 최근 10년 동안 수질이 더욱 악화되었음을 알 수 있다.

In order to disclose the contamination of the Mushim-Cheon by pollutants in August and September of 1989 and to establish countermeasures, the collected water samples were analyzed to obtain the following results : 1. The water temperature of the period ranged from 25.8 to $30.8^{\circ}C$ acceptable for the growth of microorganisms and algae to allow the self-purification of the stream. 2. The pHs at the sites during the same period ranged from 6.5 to 8.5 which fall within the allowed values for the first grade water supplies except for site 14. 3. At site 18 which is the confluence of the sewer of the excretion disposal facilities and the main stream, the DO was observed to fall down to 0.7 ppm in September. 4. The BOD value reached a maximum of 62.1 ppm at site 18, which far exceeded the limit of 40 ppm, the allowed value for the discharges from the disposal facilities. In addition, the SS values were 200 and 520 ppm in August and September, respectively, which were three to seven times as high as the allowed limit of 70 ppm. 5. The high $NH_3-N$ value of 46.2 ppm at site 18 in September suggested that the water was heavily contaminated with excretions. 6. The BOD load of the sewage from site 12, the Sajik-Dong Sewer, in September was estimated to be about 0.306 ton/day. 7. The contamination of the influents, the family wastewater, and the discharges from the disposal facilities was greater than that of the main stream. 8. In the samples collected from site 12, the Sajik-Dong sewer at an interval of every two hours, a close correlation was observed between the pollutant load and the life cycle of the nearby inhabitants. 9. Compared with the results obtained from the water samples in 1979, it was observed that the water was heavily contaminated at site 12 (the Sajik-Dong Sewer, under the Chung Ju Great Bridge) and site 15 (Under the 2nd Uncheon Bridge) over the last 10 years, with little difference at site 9(Young Un-Dong water supply source).

강우시 유출되는 비점원오염물질의 유출특성을 조사하고, 수영만에 있어서 하천오염물질이 만내로 유입되어 미치는 영향을 4가지 경우인 점원오염부하가 미치는 영향(Case 1), 연간 비점원오염부하가 미치는 영향(Case 2), 우기시 오염부하가 미치는 영향(Case 3)과 실측강우 조사기간동안 비점원오염부하가 미치는 영향(Case 4)으로 나누어 예측 및 평가하였다. 이상의 연구 결과를 요약하면 다음과 같다. 비점원오염물질의 특성을 보면 강우시 하천의 수질변동은 강우강도와 유량의 증감과 매우 밀접한 관계를 가지고 증감한다 COD, TSS와 VSS의 경우는 2차 강우 후 유량이 최대인 $65.736m^3/s$가 될 때 오염물질의 최대치가 나타났는데 최대치는 각각 121.4mg/l, 1148.0mg/l와 262.0mg/l를 보여주었다. 그리고 영양염류인 경우는 1차 강우가 시작되어 유량이 1차 최대치인 $4.686m^3/s$로 증가할 패 최대치를 보여주는데 $TIN,\;NH_4\;^+-\;N,\;NO_2\;^--N$과 $PO_4\;^{3-}-P)$는 각각 20.306mg/l, 14.154mg/l, 9.571mg/l와 1.785mg/l를 나타내며 2차 강우가 시작된 후 약간 증가하다가 감소하였다. 해수유동모델에 의한 결과를 보면 만내 유향은 낙조시에 시계방향으로 창조시에 반시계방향으로 북동-남서방향이다. 만내 조류속은 최대 0.3m/s이고 만외 유속은 0.4m/s 정도이며 계산치는 관측치와 매우 유사하게 재현되고 있다. 확산모델의 보정은 점원오염부하량이 만내에 미치는 영향을 수영만내 관측치를 이용해 반복 시뮬레이션하여 보정하였고 보정결과 COD, SS의 계산 결과는 관측치와 잘 일치하였다. 확산모델의 적용결과 수영강의 오염부하는 낙조시에는 해운대 해수욕장으로 창조시는 광안리 해수욕장으로 수질을 악화시켰다. 비점원오염부하가 만내에 미치는 영향을 재현시킨 결과 연간 강우로 인한 비점원오염부하(Case 2)와 우기시 강우로 인한 오염부하(Case 3)가 미치는 영향은 점원오염부하(Case 1)가 만내 수질이 미치는 영향과 비교해 광안리 해수욕장의 오염부하를 약간 증가시키며 큰 차이는 보이지 않았다. 강우 조사시 비점원오염부하가 미치는 영향(Case 4)은 수영만내에 매우 심각한 오염현상을 보여준다. 낙조시에는 COD와 SS의 만내의 농도 분포는 각각 2.0-30.0mg/l와 7.0-200.0mg/l를 보여준다. 낙조시에는 창조시보다 낮은 오염정도를 나타내나 해운대 해수욕장으로는 높은 오염을 가중시키는 것을 볼 수 있다. 그러나 강우가 멈춘 후 24시간이 경과하여 실측한 수영만의 오염분포를 보면 건기시 해역농도에 비해 약간 높은 농도분포를 보여 주는 것으로 보아 입자가 큰 침강성 고형물질의 빠른 침강과 수영만내 해수유동으로 인해 빠르게 확산되어 농도가 감소되는 것으로 보인다. 그러나 강우가 시작한 후 매우 높은 오염물질을 함유하는 강우유출수가 만내로 유입될 때의 충격부하는 수영만의 해양생태계에 심각한 영향을 미치리라 예상되며 만약 이들 강우유출수를 처리하여 만내로 유출시키면 만내 수질은 개선되리라 사료된다.

The most obvious and easily recognizable sources of potential water pollution are point sources such as domestic and industrial wastes. But recently, the potential effects of nonpoint sources on water quality have been increased apparently. In order to evaluate the characteristics and the effects of nonpoint sources on water quality, this study was performed in Suyeong Bay from May, 1992 to July, 1992. The depth-averaged 2-dimensional numerical model, which consists of the hydrodynamic model and the diffusion model was applied to simulate the water quality in Suyeong Bay. When flowrate was $65.736m^3/s,$ the concentration of pollutants (COD, TSS and VSS) at Oncheon stream (Sebeong bridge) during second flush were very high as much as 121.4mg/l of COD, 1148.0mg/l of TSS and 262.0mg/1 of VSS. When flowrate was 4.686m^3/s, the concentration of pollutants $(TIN,\;NH_4\;^+-\;N,\;NO_2\;^--N\;and\;PO_4\;^{3-}-P)$ during the first flush were very high as much as 20.306mg/1 of TIN, 14.154mg/1 of $NH_4\;^+-N$, 9.571mg/l of $NO_2\;^--N$ and l.785mg/l of $PO_2\;^{3-}-P$ As results of the hydrodynamic model simulation, the computed maximum velocity of tidal currents in Suyeong Bay was 0.3m/s and their direction was clockwise flow for ebb tide and counter clockwise flow for Hood tide. Four different methods were applied for the diffusion simulation in Suyeong Bay. There were the effects for the water quality due to point loads, annual nonpoint loads and nonpoint loads during the wet weather and the investigation period, respectively. The efforts of annual nonpoint loads and nonpoint loads during the wet weather seem to be slightly deteriorated in comparison with the effects of point loads. However, the bay was significantly polluted by the nonpoint loads during the investigation period. In this case, COD and SS concentrations ranged 2.0-30.0mg/l, 7.0- 200.0mg/l in ebb tide, respectively. From these results, it can be emphasized that the large amount of pollutants caused by nonpoint sources during the wet weather were discharged into the bay, and affected significantly to both the water quality and the marine ecosystem. Therefore, it is necessary to consider the loadings of nonpoint pollutants to plan wastewater treatment plant.

강우시 유출되는 비점원오염물질의 유출특성을 조사하고, 수영만에 있어서 하천오염물질이 만내로 유입되어 미치는 영향을 4가지 경우인 점원오염부하가 미치는 영향(Case 1), 연간 비점원오염부하가 미치는 영향(Case 2), 우기시 오염부하가 미치는 영향(Case 3)과 실측강우 조사기간동안 비점원오염부하가 미치는 영향(Case 4)으로 나누어 예측 및 평가하였다. 이상의 연구 결과를 요약하면 다음과 같다. 비점원오염물질의 특성을 보면 강우시 하천의 수질변동은 강우강도와 유량의 증감과 매우 밀접한 관계를 가지고 증감한다 COD, TSS와 VSS의 경우는 2차 강우 후 유량이 최대인 $65.736m^3/s$가 될 때 오염물질의 최대치가 나타났는데 최대치는 각각 121.4mg/l, 1148.0mg/l와 262.0mg/l를 보여주었다. 그리고 영양염류인 경우는 1차 강우가 시작되어 유량이 1차 최대치인 $4.686m^3/s$로 증가할 패 최대치를 보여주는데 $TIN,\;NH_4\;^+-\;N,\;NO_2\;^--N$과 $PO_4\;^{3-}-P)$는 각각 20.306mg/l, 14.154mg/l, 9.571mg/l와 1.785mg/l를 나타내며 2차 강우가 시작된 후 약간 증가하다가 감소하였다. 해수유동모델에 의한 결과를 보면 만내 유향은 낙조시에 시계방향으로 창조시에 반시계방향으로 북동-남서방향이다. 만내 조류속은 최대 0.3m/s이고 만외 유속은 0.4m/s 정도이며 계산치는 관측치와 매우 유사하게 재현되고 있다. 확산모델의 보정은 점원오염부하량이 만내에 미치는 영향을 수영만내 관측치를 이용해 반복 시뮬레이션하여 보정하였고 보정결과 COD, SS의 계산 결과는 관측치와 잘 일치하였다. 확산모델의 적용결과 수영강의 오염부하는 낙조시에는 해운대 해수욕장으로 창조시는 광안리 해수욕장으로 수질을 악화시켰다. 비점원오염부하가 만내에 미치는 영향을 재현시킨 결과 연간 강우로 인한 비점원오염부하(Case 2)와 우기시 강우로 인한 오염부하(Case 3)가 미치는 영향은 점원오염부하(Case 1)가 만내 수질이 미치는 영향과 비교해 광안리 해수욕장의 오염부하를 약간 증가시키며 큰 차이는 보이지 않았다. 강우 조사시 비점원오염부하가 미치는 영향(Case 4)은 수영만내에 매우 심각한 오염현상을 보여준다. 낙조시에는 COD와 SS의 만내의 농도 분포는 각각 2.0-30.0mg/l와 7.0-200.0mg/l를 보여준다. 낙조시에는 창조시보다 낮은 오염정도를 나타내나 해운대 해수욕장으로는 높은 오염을 가중시키는 것을 볼 수 있다. 그러나 강우가 멈춘 후 24시간이 경과하여 실측한 수영만의 오염분포를 보면 건기시 해역농도에 비해 약간 높은 농도분포를 보여 주는 것으로 보아 입자가 큰 침강성 고형물질의 빠른 침강과 수영만내 해수유동으로 인해 빠르게 확산되어 농도가 감소되는 것으로 보인다. 그러나 강우가 시작한 후 매우 높은 오염물질을 함유하는 강우유출수가 만내로 유입될 때의 충격부하는 수영만의 해양생태계에 심각한 영향을 미치리라 예상되며 만약 이들 강우유출수를 처리하여 만내로 유출시키면 만내 수질은 개선되리라 사료된다.

The most obvious and easily recognizable sources of potential water pollution are point sources such as domestic and industrial wastes. But recently, the potential effects of nonpoint sources on water quality have been increased apparently. In order to evaluate the characteristics and the effects of nonpoint sources on water quality, this study was performed in Suyeong Bay from May, 1992 to July, 1992. The depth-averaged 2-dimensional numerical model, which consists of the hydrodynamic model and the diffusion model was applied to simulate the water quality in Suyeong Bay. When flowrate was $65.736m^3/s,$ the concentration of pollutants (COD, TSS and VSS) at Oncheon stream (Sebeong bridge) during second flush were very high as much as 121.4mg/l of COD, 1148.0mg/l of TSS and 262.0mg/1 of VSS. When flowrate was 4.686m^3/s, the concentration of pollutants $(TIN,\;NH_4\;^+-\;N,\;NO_2\;^--N\;and\;PO_4\;^{3-}-P)$ during the first flush were very high as much as 20.306mg/1 of TIN, 14.154mg/1 of $NH_4\;^+-N$, 9.571mg/l of $NO_2\;^--N$ and l.785mg/l of $PO_2\;^{3-}-P$ As results of the hydrodynamic model simulation, the computed maximum velocity of tidal currents in Suyeong Bay was 0.3m/s and their direction was clockwise flow for ebb tide and counter clockwise flow for Hood tide. Four different methods were applied for the diffusion simulation in Suyeong Bay. There were the effects for the water quality due to point loads, annual nonpoint loads and nonpoint loads during the wet weather and the investigation period, respectively. The efforts of annual nonpoint loads and nonpoint loads during the wet weather seem to be slightly deteriorated in comparison with the effects of point loads. However, the bay was significantly polluted by the nonpoint loads during the investigation period. In this case, COD and SS concentrations ranged 2.0-30.0mg/l, 7.0- 200.0mg/l in ebb tide, respectively. From these results, it can be emphasized that the large amount of pollutants caused by nonpoint sources during the wet weather were discharged into the bay, and affected significantly to both the water quality and the marine ecosystem. Therefore, it is necessary to consider the loadings of nonpoint pollutants to plan wastewater treatment plant.

광주천의 5개 지점에서 2003년 4월부터 2004년 2월 까지 부유 및 부착 조류를 조사한 결과 총 8강 19목 6아목 35과 4아과 79속 274종이 동정되었다. 군집 구조는 규조류가 절대우점하는 가운데, 녹조류와 남조류 등이 포함된 다양한 종조성을 나타냈다. 조사기간 동안 부유조류는 방림교정점과 양동시장정점에서 총 137종이 채집되어 가장 다양한 부유조류 분포를 나타냈고, 유촌교정점에서 118종이 출현하였으며 동산타워정점에서는 50종이, 증심천정점에서는 43종이 출현하였다. 월별 출현종 변화는 양동시장정점에서 가장 컸고 동산타워정점에서 가장 작았으며 강우가 출현종 변이의 큰 요인이었다. 부착조류도 규조류가 가장 높은 비율을 차지하였다. 광주천 조류의 성장에 영향을 미치는 요인의 분석에서 조류의 총 개체수와 성관성을 가장 크게 보인 요소는 클로로필 a (평균: R=0.795)의 농도인 것으로 나타났다. 조류 성장에 중요한 영양염류인 TN과 TP도 양동시장정점에서 상관성이 높은 것으로 나타났으며, 기상요인으로는 7일 전 강우와 총 개체수 사이에 비교적 높은 상관성이 나타났는데 광주천의 상류인 동산타워정점에서 R=0.810의 상관도를 기록하였다. 기온과 습도는 거의 상관관계를 보이지 않았고, BOD와 COD, DO, pH의 경우도 미미한 상관관계를 나타냈다. 총 개체수에 영향을 미치는 여러 가지 요인들에 대한 상관관계를 지점별로 살펴 보면, 동산타워정점에 가장 큰 영향을 미치는 요인은 조사시점의 7일 전 강우로 상류에서 하류로 갈수록 그 영향력이 감소되었다. 클로로필 a의 농도와 개체수의 상관성은 개체수가 점차로 증가하는 하류에서 그 상관성이 높았으며, 이 두 가지 요인을 제외한 나머지 pH, DO, BOD, COD, SS, TN, TP 등은 모두 가장 하류인 유촌교정점에서보다 양동시장정점에서 더 높은 상관관계를 나타냈다.

The distributions of planktonic and periphytic algae were studied from April 2003 to February 2004 at Gwangju Stream. A total of 274 species, belongs to 8 classes, 19 orders, 6 suborders, 35 families, 4 subfamilies, 79 genera, was identified as algal flora of Gwangju Stream. The most diverse phytoplankton flora was observed at Bangrim bridge and Yangdong market sites with 137 species, and followed by Yuchon bridge site (118 species). The richness of phytoplankton fluctuated throughout the studied period from all the sampled sites. The precipitation was a major factor affected the richness of phytoplankton. The diatoms predominated the phytoplankton of Gwangju Stream with 57.7~77.0% of total phytoplankton. The maximum cells of phytoplankton was observed at Yuchon bridge site with 23,792 cells $mL^{-1}$ in August 2003, and minimum at Jeungsimsa site with 82 cells $mL^{-1}$ in April 2003. The periphyton of Gwangju Stream was predominated by the diatoms. In February 2004, all the periphyton of Yuchon bridge site were diatoms. Other sites also showed the predominance of diatoms throughout the studied period. The standing crops of phytoplankton were highly correlated with chlorophyll-a concentration with R=0.795. TN and TP also showed high relationships with phytoplankton standing crops in Yangdong market site with R=0.796 and R=0.760, respectively. The rains of 7-days ago showed high relationships with phytoplankton standing crop at Dongsan tower site with R=0.810. However, other climatic factors showed no clear relationships with phytoplankton cells.

최근 해상 교량공사에서는 환경적인 문제로 인해 수심이 낮은 구간에서도 축도 대신 가교를 통한 시공이 요구되고 있으며 이에 따라 가설교량 구간이 크게 증가하고 있다. 이렇게 수심이 낮은 구간에서의 가교 가설은 해상장비의 사용이 제한되므로, 크레인을 이용한 단계별 전진가설 공법으로 공사가 수행되지만 크레인의 용량에 따라 장경간화 제약 및 가설 기간 증가를 초래한다. 따라서 해상공사의 경쟁력 확보 및 효율적 시공을 위해 가설교량의 설계최적화를 통한 물량 감소 및 절대 공기를 단축 할 수 있는 공법에 대한 연구가 필요하다. 본 연구에서는 고강도 강재의 적용 및 트러스형 안전난간을 부재로 활용하여 가교의 장경간화 및 처짐 제어 방안을 제시하였다. 연구 결과, 동일한 단면 및 하중 조건에서 SS400 강재 적용 시 최대경간이 14 m까지 가능했지만, SM490강재 및 트러스형 안전난간 적용 시 경간을 21 m까지 증가시킬 수 있었다. 또한 가교의 총 연장 1050 m를 기준으로 가설교량의 경간 수를 33% 줄여 하부 및 기초 가설 물량을 크게 줄일 수 있었으며, 약 2달의 공기를 단축할 수 있을 것으로 판단된다.

Recently, environmental issues have been raised in offshore bridge constructions, which requires constructing temporary bridges in shallow water levels instead of temporary embankment roads. Therefore, this has significantly increased the amount of trestle required in offshore bridge projects. Due to limitations in using marine equipments to approach shallow waters, the phased forward method needs to be implemented in constructing a trestle in shallow waters. However, depending on the capacity of the crane, the phased forward method restricts the span length of the trestle, which would critically increase the construction period. Therefore, in order to perform offshore bridge projects, more competitive approaches are required to reduce the construction period and the quantity of trestle through optimized designs. This research adopts high strength steel and truss type safety barrier as members to control deflection and propose ways of elongating the span of the trestle. Under the same conditions, the application of SM490 steel and truss type safety barrier enable the trestle span to increase up to 21 m. In addition to considering a trestle at a total length of 1050 m, the proposed approach can reduce the number of spans by 33% and decreasing the quantities of sub-structures and the construction period by approximately 2 months.

본 연구에서 개발한 시스템은 기존에 사용되던 유수분리기를 유류가 혼입되어 발생하는 도로, 교량 등의 도시 불투수면 비점 오염저감장치로 업그레이드한 것으로서 유적입자가 coalescence 원리에 의하여 고밀도 고분자 폴리에틸렌 소재를 사용하여 제작된 메디아의 표면과 공간 사이를 타고 이동하면서 합체되어 유적의 크기가 증가한 후 부상하여 제거되는 기전과 SS 성분의 고형물이 침전에 의해 제거되는 원리를 이용한 도시 비점오염저감시설이다. 따라서 본 연구에서는 coalescence 기전을 통해 유수분리가 일어나는 나선형 고분자 여재의 유수분리 특성을 image analysis를 통해 규명하였으며 또한 도로노면 먼지와 폐엔진오일을 이용하여 비점오염원 저감시설에 유입되는 폐수를 모사하여 비점오염원 저감시설의 유수분리 성능을 실험하였다. 연구에 사용된 여재는 부정형의 투명한 나선형 구조를 갖고 있으며, SEM 사진 및 BET 측정 결과 매끄러운 표면 특성을 나타내고 있다. 직접 측정 방법으로 여재의 표면적을 측정한 결과, 여재 1립당 표면적은 1,428 $mm^2$으로 나타났으며, 단위당 중량은 45.3 $kg/m^3$으로 조사되었다. 또한 폐수 내 기름 입자의 액적크기를 현미경으로 촬영하여 이미지 분석을 수행한 결과, 메디아를 통한 폐수내 기름성분의 제거가 coalescence에 의해 일어나고 있음을 증명하였다. 마지막으로 나선형 부유 메디아를 적용한 비점오염저감시설의 성능평가 결과, 유량에 따라서 부유성 고형물은 $86.6\sim95.2%$, $COD_{Cr}$, $87.3\sim95.4%$, n-Hexane 추출물 $71.8\sim94.8%$의 제거효율을 나타내어 본 장치의 처리성능은 기존의 비점오염원 저감시설의 처리대상물질인 유기물과 부유물질 뿐만 아니라 유류의 제거에도 효과적인 것으로 평가되었다.

Non-point source control system which had been designed only for oil-water separation in the fields of oil refinery and garage was upgraded in this research for the removal of runoff pollutants in impervious urban area. Pollutants including oil from driveway and bridge were eliminated by two types of pathway in the system. One is the coalescence mechanism that the oil droplets in the runoff come into contact with each other in the spiral buoyant media surface and form larger coalesced droplets of oil that are carried upstream to the oil layer. The other is the precipitation that solids in runoff were settled by gravity in the system. In this research, coalescing characteristics of oil and water separation were investigated through image analyses, and efficiencies of the non-point source control system were evaluated using dust in driveway and waste engine oil. Media made of high density and high molecular weight polyethylene was indeterminate helical shape and had sleek surface by analysing SEM photographs and BET. Surface area and specific gravity of media which were measured directly were 1,428 $mm^2$ and 45.3 $kg/m^3$ respectively. From the image analyses of the oil droplets photographs which were taken by using microscope, it was proved clearly that the coalescence was the main pathway in the removal of oil from the runoff. Finally, the performances of the non-point source control system filled up with the media were suspended solid $86.6\sim95.2%$, $COD_{Cr}$, $87.3\sim95.4%$, n-Hexane extractable materials $71.8\sim94.8%$ respectively.

In this paper, a communication method is proposed for the development of a main engine remote control system. The main engine control system compriese three subsystems such as RCS (Remote Control System) BCS (Bridge Control System) and SS (Safety System), Thus it is required to exchange data each other among these subsystems. The communication method has simplified hardware through the minimization of communication components where the interrupt method are employed for receiving and the polling method for transmitting. We discuss a methodology of using a ring buffer for data storage physically which has two buffers virtually for the effective use of memory. This communication method presents a good performance in the system which has rather small numbers of communication data.

This study was conducted to investigate of water qualities in the upper and middle reaches of the Han River. For this purpose, water was sampled at Kwangjin and 1st Han-River Bridges of the Han River in Seoul and analysed from August, 1988 to September, 1989. The results are summarized as follows : 1. Water quality at 1st Han-River Bridge was more polluted than that at Kwangjin Bridge. 2. Except biological oxygen demand (BOD), turbidity, suspended solid (SS), dissolved oxygen (DO), DO saturation (DOS), ammonia nitrogen ($NH_3-N$), nitrite nitrogen ($NO_2-N$) and chloride ion ($Cl^-$) at Kwangjin and 1st Han-River Bridges were lower as compared with the previous data before redevelopment of the Han River. 3. SS, DO and pH at Kwangjin and 1st Han-River Bridges could be classified to the 1st grade in environmental water quality standard. DOS at Kwangjin Bridge was over 100% and that at 1st Han-River Bridge was below 100% in the Han River. BOD at Kwangjin Bridge could be classified to End grade and that at 1st Han-River Bridge to 3rd grade in environmental water quality standard. 4. The higher the level of water was, the lower the levels of turbidity and SS, and $NH_3-N$ was decreased with increasing water level at 1st Han-River Bridge. DO was decreased as water temperature went up but DOS was increased with DO. BOD was positively correlated with nitrite-nitrogens. 5. Turbidity and SS at the both sites and Chloride ion ($Cl^-$) at Kwangjin Bridge were increased in July and August. And DO at the both sites and $NH_3-N$ at 1st Han-River Bridge were decreased in at July and August.

This study was carried out forecasting of pollution inflow of the Small Mountainous Catchment, namely; Seolma-cheon experimental catchment. Pollutographs of DO, BOD, T-N, Conductivity, T-p, pH. COD, SS from this catchment were obtained from in-situ data of total ten events using QUAL2E-PULS model. From the analysis results, between up stream(Sabang-bridge) and down stream (Memorial-bridge, outlet) obtained relation formula of water quality component. Determination coefficient of relation formula, Conductivity, COD, BOD, DO, pH, T-N, T-P, and SS showed high relation of $0.87{\sim}0.99$. The increases of DO, BOD, COD, and pH concentration of Memorial-bridge were associated with pollution inflow by road building far 2.25km from Sabang-bridge to down stream. The analysis results of QUAL2E-PULS simulation and up/down stream relation formula, pollution amounts of DO, BOD, COD and pH increased at Memorial-bridge and pollution source site. Therefore, pollution inflow can be forecasted exactly by up/down stream relation formula at pollution source site.

This study was performed to investigate the stream water quality characteristics in Hengjeong Bridge Basin of Dongjin River during twelve months from October, 2010 to September, 2011. Also, pollutant loads were calculated on the basis of the water quality and runoff results. The results showed that ranges of water temperature, pH and EC were $6.2{\sim}23.90^{\circ}C$, 6.32~7.78, $84.4{\sim}126.5{\mu}S/cm$ respectively. The Concentration of DO, BOD, COD, SS, Tot-N and Tot-P were observed as 6.80~9.20 mg/L, 0.40~1.60 mg/L, 1.96~4.41 mg/L, 59.60~142.20 mg/L, 1.28~3.52 mg/L, 0.001~0.07 mg/L respectively. Tot-N showed correlativity with BOD, and Tot-P showed correlativity with SS. The runoff pollutant loading of Tot-N and Tot-P were 117.94 kg/ha and 2.06 kg/ha respectively, in Hengjeong bridge of Dongjin river watershed. In the case of the correlativity between runoff pollutant loads and concentrations, Tot-N and Tot-P show low significant relationships.

The purpose of the present study is to analyze pollutant runoff characteristics from non-point sources in Joman River basin. The present study contains analyzed results of rainfall and SS, BOD, COD, TN, TP runoff from Joman River basin. This study contains a sensitivity analysis of parameters that affect the simulation results of rainfall and pollutants runoff. Result of the sensitivity analysis shows that proportion of watershed and impervious areas is the most sensitive to peak discharge and total flowrate for rainfall runoff and that WASHPO is the most sensitive parameter for pollutants runoff. For parameter estimation and verification, flowrate and water quality is measured at the Kangdong Bridge in Haeban stream. A single rainfall event is use to perform parameter estimation and verification. Results of the present study show that total pollutant loads of Joman River basin is 11,600 ton of SS, 452 ton of BOD, 1,084 ton of COD, 515 ton of TN, and 49 ton of TP, respectively. In addition, it is found that contribution ratio of non point source and total source is 89% of SS, 63% of BOD, 61% of COD, 21% of TN, and 32% of TP, respectively.

In view of ever rising water pollution problems of river in the vicinity of large urban communities, the author has made an investigation on the pollution of water sampled from Han River (Seoul area) and Nakdong River (Daegu city area) during the period from July to December, 1970. The water samples were taken twice a month during the study period of 6 months from 7 points (locations) along the main stream of Han River at Seoul city and 5 points of Nakdong River at Daegu city. The samples ware measured and analyzed in accordance with the recognized methods in the 'Standard Methods for Examination of Water and waste' by American Public Health Association. The obtained results are as follows : I. Han River. 1. Average turbidity was 5.1 units ranging from 1 to 10 units and the turbidity of down stream was higher than that of the upper stream. 2. pH value showed slight alkalinity (mean;7.2) except Yunchang-Dong (6.9). 3. The mean value of Dissolved Oxygen contents (D.O) was 7.2 ppm. (range of 3.4-10.5ppm.). D.O. of the upper stream (8.2 ppm. at Walker Hill boating place, 8.0 ppm. at the Gwangzang Bridge and Ddookdo) was higher than that of he downstream (5.6ppm. at Yumchang-Dong, 6.4 ppm. at the 2nd Han River Bridge), and D.O. in the winter season was higher than that in the summer season, respectively. 4 The mean value of the Biochemical Oxygen Demand (B.O.D.) was 28.3 ppm. (range of 6.2-64.8 ppm.). The mean value of B.O.D. was 48.7 ppm. at Yumchang-Dong, 42.3 ppm. at the 2nd Han River Bridge, 34.0 ppm. at the 1st nan River Bridge, 28.5 ppm. at the 3rd Han River Bridge, 19.2 ppm. at Dookdo, 13.2 ppm. at the Gwangzang Bridge, and 10.2 ppm. at the Walker Hill boating place in order of value. B.O.D. in July and August (35.6 and 34.5 ppm.) were the highest and that in November and December (18.6 and 21.2 ppm.) were the lowest. 5. Suspended Solids (SS) were from 15.0 to 667.0 ppm. with the mean of 222.1 ppm. 'Suspended Solids' of the water samples at Yumchang-Dong and the 2nd Han River Bridge were found to be 378.1 ppm. and 283.9 ppm. respectively which were higher than at the Gwangzang Bridge (134.1 ppm.) and at Walker Hill boating place (79.3ppm.). 6. Coliform colonies counting of the water samples ranged from $0-2,500{\times}10/100ml$. with the mean value of $205.6{\times}10/100ml$. The most contaminated water sample by coliform were from the point of the 2nd Han River Bridge with $640.8{\times}10/100ml$ while the lowest ones were from Walker Hill boating place with $17.2{\times}10/100ml$. There was also a seasonal variation in coliform contamination that is the higher in summer and the lower in winter. II. Nakdong River 1. The mean value of turbidity was 2.3 units with range of 0 to 9.0 units. The highest point was at Geumho River (7.2 units). and the lowest point was at Gangzung and Moonsan (0.45 and 0.41 units). 2. The mean value of pH was 7.5 (range of 7.1-8.5) and highest point was Geumho River with 8.5. 3. The mean value of D.O. was 8.1 ppm. (range of 3.4-11.2 ppm.). D.O. of the upper stream showed higher value than that of the down stream, and the winter season than the summer season. 4. B.O.D. ranged from 2.6 to 57.0 ppm. (mean; 20.4ppm.). The water sample at Geumho River showed the highest value (41.5 ppm.) while at Moonsan and Gangzung showed the lowest (4.6 and 4.7 ppm.). 5. The mean value of suspended solids was 48.7 ppm. (range of 4.0-182.0 ppm.). The highest month was July (63.7ppm.) and August (62.1 ppm.) and the lowest month was October (37.0 ppm.) and December (24.4 ppm.). 6. The mean value of the coliform colonies was $22.7{\times}10/100ml$. (range of $0-243{\times}10/100ml$.). The highest number of the colonies was found in the sample water at the Whawon recreation area ($50.5{\times}10/100ml$.) followed by the Geumho River ($33.9{\times}10/100ml$.), the Goryung Bridge ($28.3{\times}10/100ml$.), Gangzung($0.7{\

The tributaries of Daechung Lake play an important role in controlling eutrophication in the lake, which is used for agricultural purposes and as potable water. However, water quality properties were not extensively studied in the tributaries of Daechung Lake. The objectives of this study are to investigate spatial and temporal properties of water quality and to characterize streams which could threaten water quality of Daechung Lake. For this study, water samples were weekly or monthly collected from February 2014 to October 2014 in 9 streams. Water quality parameters analyzed in this study include biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), total nitrogen and phosphorus (TN and TP), suspended solids (SS), and chlorophyll a. Based on temporal distribution and principal component analysis, BOD, COD, TOC, SS, and TP were controlled by not only river discharge that increased during summer due to heavy rain fall, but also due to anthropogenic input (e.g., bridge construction and/or agricultural activity). Dilution is also one of the factors explaining TN and conductivity, both of which decreased with increased discharge. Generally, concentrations of contaminants (BOD, COD, TOC, TN and TP) in the tributaries were higher than those of Daechung Lake. However, pollution load indicated that only the main channel of Geum River and Sook Stream may largely influence lake waters, attributed mostly to their large volumes. This implies that the main channel and Sook Stream are the major influences on the water quality of Daechung Lake.

The pollution characteristics of water quality analysis and the heavy metal analysis of river sediment in the Western Nakdong river, and then a commercial tile using the polluted sediment was produced. The analytical results of the riverbed structure and the depth distribution in the Western Nakdong river were that Macdo Stream(site 2) was the deepest(13 ft). The analytical result of water quality showed that BOD was the highest in the Hogei Stream(site 6); COD, Syanduengchi Island(site 1);SS, Macdo Stream(site 2);T-N, Suanduengchi Island(site 1);T-P, Macdo Stream(site 2). Therefore the deeper the site was the higher the pollution concentration was. The result of heavy metal analysis of the river sediment was that Pb and Cr were the highest in Kangdong Bridge(site 9); Cd, Macdo Stream(site 2), so the deeper the site was the higher the pollution concentration was. The production of tile using the mixure of the polluted sediment and the raw material was successful, so the reuse of polluted sediment was possible.