댐 및 하천제방에 대한 위험도 해석을 위해 유역의 상류부에 두 개의 댐이 공존하고 있는 하천유역에 적용하였다. 그 결과, A댐의 경우 200년 빈도의 강우조건에 대해서는 안전했으나 PMP 조건하에서 위험도를 나타내고 있었고, B댐의 경우는 200년 빈도 및 PMP 조건하에서 안전한 것으로 나타났다. 유역의 유출계수, 초기수위 및 댐과 여수로와 관련된 자료의 불확실도를 고려하여 계산된 위험도는 Monte-Carlo 기법과 AFOSM 기법에 있어 대등한 결

본 연구는 댐 및 하천제방에 대한 수문학적 위험도 평가를 위해서 Monte-carlo 기법과 AFOSM 기법에 의한 위험도 모형을 개발하였다. 댐 및 제방에 대한 위험도 해석을 위하여 fault tree를 작성하였고, 단계별 위험도 평가과정을 제시하였다. 본 연구의 위험도 모형은 모형 매개변수에 대한 변동성을 고려하여 강우-유출해석, 저수지 추적, 하도추적 등으로 구성하였다. 강우-유출해석에 있어서는 200년 빈도 및 PMP에 의한 설계강우에 대한 KR

전자파를 이용한 하천수 표면 유속계를 하천 유량 측정에 사용하여 실용성과 문제점을 분석하였다. 표면 유속계의 평가는 선박 실험용 선형수조를 이용하여 수행하였다. 그 결고, 수직각을 20, 35, 45로 하였을 때 유속측정 평균값의 오차는 5.5% 이하였다. '95년 8월 26일 8~10시 사이에는, 남한강 여주대교 지점에서 홍수 유속을 측정하였다. 500m 길이의 교량에 대하여 23개 지점에서 측정한 결과, 표면 유속값은 약 2~4m/s였다. 수심평균

본 연구에서는 (1) 운동과 이론에 기초한 강우, 유출 특성을 파악하고, (2) 강우 및 유수에 의해서 발생하는 침식, 퇴적량을 산정하는 모형을 연구하며, (3) 유사량 산정식, 유역의 불할 수 등이 하상변동 예측에 미치는 영향을 분석하고, (4) 평창강 유역에서 하도자료, 강우, 유츨량, 유사량 등을 실측하여 모형의 적용성을 검증하였다. 운동파 방정식을 평창강 유역에 적용하여 유출해석을 실시한 결과, 첨두 유량의 발생시간은 다소 빠르게 계산되었으나 전

Still today, many streams are channelized and embanked in Korea. On the other hand, some urban streams are being restored to their natural shapes by landscape planners. It would be better to improve rural streams in a way that would not require restoration in later days. Then, one important question is what kind of embankments the residents prefer for what reasons. Five simulated photos showing from very natural to artificial embankments were used in surveying 90 residents of three villages. Major findings are ; 1. Residents regard safety(from flooding) is the most critical factor to be considered in selection of stream bank materials. 2. They think ideal materials are natural stones or concrete blocks as they look tidy. Concrete retaining walls or vegetated natural slopes are not regarded good. 3. The most preferred material is concrete retaining wall, and the least preferred is vegetated natural slope. They prefer concrete retaining wall which they do not think an ideal material, because it will make a safe bank. 4. Natural stone bank is most preferred for its apperance, and vegetated natural slpoe is most disliked as it may collapse and as it does not look clean.

본 연구는 중소하천 유역에서 강우-유출과정의 모의절 위한 정도 높은 개념적 모형을 결정하기 위하여 기존의 개념적 선형 모형인 Clark 모형, Nash 모형과 개념적 비선형 모형인 Laurenson 모형과 WBN 모형을 위천 유역을 대상으로 적용 및 비교검토를 하였다. 선형 모형에서 산정된 매개변수들의 변동성은 비선형 모형의 매개변수의 변동성 보다 크게 나타났으며, 계측유역에서 4개 개념적 모형으로부터 합성한 수문곡선을 분석한 결과 첨두유량은 4개 모형

하천환경의 개선을 위하여 필수적인 요소인 하천 내 수목의 분포현황을 조사하고, 이들 수목의 외력에 저항하는 내력에 대한 현장실험을 통해 연구하였다. 하천 내 수목의 분포 현황은 전국의 11개 하천 수계의 직할하천 구간을 중심으로 조사되었다. 수목분포 조사결과 국내의 하천에 전국적으로 자생하는 수목은 버드나무과에 속하는 갯버들, 버드나무, 왕버들 등의 수목임을 확인하였다. 현장시험은 홍수시 하천 내의 수목이 물의 흐름에 의해 인발되어 하류에 있는 하천구조

The purpose of this study is to analyze structural and ecological characteristics of streams in rural village. The methods used in this study were measuring the section and surveying the vegetation of the stream at three points(upstream, inner village, downstream ) of 10 rural villages. The major findings of this study can be summarized as follows : 1) The average width of streams is 9 m, and the height of banks 3.1 m. the downstreams are the widest(average 10 m), and the inner-villages are the narrowest (average 8 m), and the slopes of basin are 7.33 %, 2.67 %, 1.39 % at upstream, inner-village, downstream respectively. 2) The downstreams are more contaminated than upstreams due to the sewage from the residents, especially livestock wastewater. 3) The dominant species in the streams are Persicaria thunbergii H. Gross (average Cover 17.76 %) and cumulus japonicas Sieb et. Zucc (average Cover 7.75 % ). 4) The average area covered by vegetation is 53.31 % the downstreams are covered 65.7 %, but inner-village area covered by vegetation is 46.6 %. 5) The problem found in this study are severe water contamination, poor accessibility to stream and poor vegetation of inner-village area, etc.

소하천 수계인 원주천의 지형학적 특성은 Hortoh-Strahler의 하천 차수법칙에 따라 일정한 규칙을 갖고 발달하였다. 이미 인접 유역에의 적용을 통해 검정과 검증이 이루어진 강우-유출모형인 NWS-PC 모형에 의해 모의발생한 일유량과 Manningtlr의 적용결과로 원주교 지점에서의 수리특성을 분석하였다. 산정된 원주천의 형태학적 특성계수에 의한 단위유량도의 첨두유량 및 이의 발생시간을 분석하였다. 비록 이같은 연구가 초기단계이기는 하나, 이 결과

The sediment in the highly contaminated Gamjeon brook was collected, mixed with the raw material of the tile, and then the commercial tile was produced using the mixture. The concentrations of the heavy metals in the mixture-before and after the tile was produced-were analyzed and the effects of the acid solution on the produced file were examined. The production of the tiles was successful and the result of heavy metal analysis showed that the concentration of Fe was the highest and that of Cd was the lowest The amount of heavy metal in the sediment - the raw material of the tile mixture was more than that of the produced tile. The elution concentration of the heavy metal by the acid solution(pH = 4 - 7) was low and the quality of the produced tile was better than the commercial tile. The result of this study suggested that the contaminated sediment was removed to produce good tiles, therefore the water pollution and soil pollution were reduced.

The purpose of this study Is to develop water quality management system fort a farm village stream. The framework design of the system and the ecological monitoring of a test watershed were carried out, The system consists of GIS(Geographic Information System ), database, pollution source management, water quality and hydrologic analysis. Suri watershed located on Idong, Yongin city, Kyunggi Province, was selected as the test watershed for the application of the system. The fifteen's monitoring stations were chooses at up- and down-stream of the watershed. The results of an aquatic ecological monitoring were analyzed by the GPI(Group Pollution Index) method. The GPI revealed that water quality was varied within the stream. GPI and DO map for the watershed stream were developed, These maps facilitated to analyze the spatial distribution of the water quality.

This study aims at the estimation of a river management flow in urban basin analyzing Sinchun basin to be the tributary of Kumho river basin. The river management flow has to satisfy a low flow as natural flow and an environmental preservation flow estimated by a dilution flow to satisfy a target water quality in drought flow. Therefore for the estimation of a river management flow in Sinchun in this study, first Tank model as a basin runoff model estimates a low flow, a drought flow from a flow duration curve in Sinchun, second QUAL2E model as water quality model simulates water quality in Sinchun and estimates environmental preservation flow to satisfy a target water quality, BOD 8 ㎎/ℓ by a dilution flow derived from Kumho river, Nakdong river and ground water. And the river management flow is estimated by addition of a use flow and a loss flow to more flow between a low flow and an environmental preservation flow.

The purpose of this study is to develop a linear reservoir model with Kalman filter using Kalman filter theory which removes a physical uncertainty of rainfall-runoff process. A linear reservoir model, which is the basic model of Kalman filter, is used to calculate runoff from rainfall in river basin. A linear reservoir model with Kalman filter is composed of a state-space model using a system model and a observation model. The state-vector of system model in linear reservoir model with Kalman filter takes the ordinate of IUH from linear reservoir model. The average value of the ordinate of IUH for a linear reservoir model with Kalman filter is used as the initial value of state-vector. A linear reservoir model with Kalman filter shows better results than those by linear reserevoir model, and decreases a physical uncertainty of rainfall-runoff process in river basin.

Gernerally, it is difficult to predict water quality in a tidal river, because tidal flows make the transport phenomena more complicated. The purpose of this study is to clarify long-term mass transport in a tidal river through suggestion of simulation model. A simulation model based on a Lagrangian coordinate system, which has the advantage reducing numerical dispersion, was used to calculate changes in concentration of chlorides. Several field surveys were conducted to verify calculated results. Concludingly, long-term behavior of mas transport in a tidal river can be represented using the model.

Laboratory batch experiments were conducted,using suspended solids and sediments taken from a tidal section of the Rokkaku river,to study the effect of salinity on nitrification and to estimate kinetic parameters of it. Experimental results indicated much more inhibitation of NO_2-N oxidation by chlorides than that of NH_4-N oxidtion. Nitrifying bacteria in sediments were less sensitive to chlorides than those in SS. The change of nitrogen concentration with time was clearly explained with the Monod growth model and the kinetic parameter, were obtained by the curve fitting method.