• 농촌계획
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• 제17권2호
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• pp.23-32
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• 2011

The purpose of this study is to produce basic planning criteria required in ecological restoration and improvement works of streams in rural area through the application of stream assessment methods (water quality, soil environment, and ecological function assessment) at 6 study sites of Han River basin. The investigation results were as followings; 1) There were the evaluation items like a manure use, salt degree, river peripheral tree, which did not fitted to apply to domestic streams, in the SVAP (Stream Visual Assessment Protocol) and NRCS Riparian Assessment that were evaluation models developed in USDA. The area inhabitants with a little knowledge and education personally seems to utilize the evaluation methods through improvement partly with an aspect that evaluation is slightly easy. 2) From the stream assessment results, the construction of diverse pools, large woody debris and isolated backwater pool are needed to improve a few of problems observed at the mostly study sites. The result of NRCS Riparian Assessment showed that the improvement of stream bank vegetative communities is needed by planting tree with deep-binding root masses, and managing of noxious weeds and exotic undesirable plants. 3) Summing up, the assessment results showed that the assessment scores were higher at upstream than downstream, the stream with totally maintenance than that with partly maintenance, the stream with slope bank than that with vertical bank, and the stream with a flood plain than that without a flood plain. So, the direction of stream maintenance projects must be set by consideration of those results.

• 농촌계획
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• 제24권2호
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• pp.21-29
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• 2018

Riparian management has become important as stream water quality as well as riparian ecosystem gain more public attentions. The objective of this study was to determine riparian widths based on the functions of nutrient removal and wildlife habitat protection and to apply for the Jinwee stream area as a preliminary case. Nitrogen and phosphorus filtration efficiencies were considered in water quality aspect, while the habitat radii of amphibian and reptiles were used for wildlife conservation purpose. In addition, observation of endangered species and human impact on wildlife disturbance in riparian area were also taken into account in determining riparian widths. The stream confluence zone was emphasized by doubling the riparian widths as the focal point for wildlife habitat conservation. As the results, three different levels of riparian widths were proposed depending on the major riparian functions and applied to the Jinwee stream section as the case study. The proposed method can be used to determine riparian width in other stream areas based on different functional focus, ie, water quality or riparian conservation purposes.

• 한국농공학회논문집
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• 제63권6호
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• pp.89-100
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• 2021

The conservation of stream habitats has been gaining more public attention and fish habitat suitability index (HSI) is an important measure for ecological stream habitat assessment. The fish habitat preference is affected not only by physical stream conditions but also by water quality of which HSI was not available due to the lack of field data. The purpose of this study is to estimate the HSI of Zacco platypus for water quality parameters of water temperature, dissolved oxygen (DO), and biochemical oxygen demand (BOD) using the water environment monitoring data provided by the Ministry of Environment (ME). Fish population data merged with water quality were constructed by spatio-temporal matching of nationwide water quality monitoring data with bio-monitoring data of the ME. Two types of the HSI were calculated by the Instream Flow and Aquatic Systems Group (IFASG) method and probability distribution (Weibull) fitting for the four major river basins. Both the HSIs by the IFASG and Weibull fitting appeared to represent the overall distribution and magnitude of fish population and this can be used in stream fish habitat evaluation considering water quality.

• 한국농공학회지
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• 제45권2호
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• pp.116-125
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• 2003

Predictions of stream water quality require both estimation of pollutant loading from different sources and simulation of water quality processes in the stream. Nonpoint source pollution models are often employed for estimating pollutant loading in rural watersheds. In this study, a conjunctive application of SWAT model and WASP model was made and evaluated for its applicability based on the simulation results. Runoff and nutrient loading obtained from the SWAT model were used for generating input data for WASP model. The results showed that the simulated runoff was in good agreement with the observed data and indicated reasonable applicability. Loading for the water quality parameters predicted by WASP model also showed a reasonable agreement with the observed data. It is expected that stream water quality could be predicted by the coupled application of the two models, SWAT and WASP, in rural watersheds.

• 한국수자원학회논문집
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• 제39권11호
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• pp.969-976
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• 2006

본 연구의 목적은 홍수범람 시에도 침수상황의 파악이 가능한 RADARSAT SAR 영상을 이용하여 안성천 농촌유역의 홍수에 의한 침수지역을 추정하고자 하였다. 분석에 사용된 영상은 안성천유역에 1998년 8월 9일에 발생한 홍수피해시기를 중심으로 홍수 전, 직후, 후의 세 시기 영상을 선정하였다. 5m DEM을 이용하여 정사보정을 실시한 후, 세 영상의 RGB 합성방법을 실시한 결과 침수된 지역의 공간적 위치를 파악할 수 있었으며, 영상간의 연산방법인 Ratio 방법을 적용하여 보다 정확한 침수영역을 추출할 수 있었다. 침수지역은 성환천과 학정천의 합류지점 부근의 농경지로 추정할 수 있었으며, 침수영역은 하천으로부터 도로 및 농로의 경계까지 진행되었음을 확인할 수 있었다. 본 연구의 결과는 농촌지역의 소규모로 산재하여 발생한 침수지역의 자료를 작성하고, 그 결과를 정량적으로 제시하는 방법으로 활용될 수 있을 것이다.

• 농촌계획
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• 제30권1호
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• pp.57-66
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• 2024

This study aimed to develop a precise vegetation cover classification model for small streams using the combination of drone remote sensing and support vector machine (SVM) techniques. The chosen study area was the Idong stream, nestled within Geosan-gun, Chunbuk, South Korea. The initial stage involved image acquisition through a fixed-wing drone named ebee. This drone carried two sensors: the S.O.D.A visible camera for capturing detailed visuals and the Sequoia+ multispectral sensor for gathering rich spectral data. The survey meticulously captured the stream's features on August 18, 2023. Leveraging the multispectral images, a range of vegetation indices were calculated. These included the widely used normalized difference vegetation index (NDVI), the soil-adjusted vegetation index (SAVI) that factors in soil background, and the normalized difference water index (NDWI) for identifying water bodies. The third stage saw the development of an SVM model based on the calculated vegetation indices. The RBF kernel was chosen as the SVM algorithm, and optimal values for the cost (C) and gamma hyperparameters were determined. The results are as follows: (a) High-Resolution Imaging: The drone-based image acquisition delivered results, providing high-resolution images (1 cm/pixel) of the Idong stream. These detailed visuals effectively captured the stream's morphology, including its width, variations in the streambed, and the intricate vegetation cover patterns adorning the stream banks and bed. (b) Vegetation Insights through Indices: The calculated vegetation indices revealed distinct spatial patterns in vegetation cover and moisture content. NDVI emerged as the strongest indicator of vegetation cover, while SAVI and NDWI provided insights into moisture variations. (c) Accurate Classification with SVM: The SVM model, fueled by the combination of NDVI, SAVI, and NDWI, achieved an outstanding accuracy of 0.903, which was calculated based on the confusion matrix. This performance translated to precise classification of vegetation, soil, and water within the stream area. The study's findings demonstrate the effectiveness of drone remote sensing and SVM techniques in developing accurate vegetation cover classification models for small streams. These models hold immense potential for various applications, including stream monitoring, informed management practices, and effective stream restoration efforts. By incorporating images and additional details about the specific drone and sensors technology, we can gain a deeper understanding of small streams and develop effective strategies for stream protection and management.

• 한국농공학회논문집
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• 제61권4호
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• pp.11-22
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• 2019

The objective of this study was to improve the cross-sectional area and height estimation method using stream width. Stream water levels should be calculated together to simulate inundation of agricultural land. However, cross-sectional survey data of small rural rivers are insufficient. The previous study has developed regression equations between the width and the cross-sectional area and between the width and the height of stream cross-section, but can not be applied to a wide range of stream widths. In this study, cross-sectional survey data of 6 streams (Doowol, Chungmi, Jiseok, Gam, Wonpyeong, and Bokha stream) were collected and divided into upstream, midstream and downstream considering the locations of cross-sections. The regression equations were estimated using the complete data. $R^2$ between the stream width and cross-sectional area was 0.96, and $R^2$ between width and height was 0.81. The regression equations were also estimated using divided data for upstream, midstream and downstream considering the locations of cross-sections. The range of $R^2$ between the stream width and cross-sectional area was 0.86 - 0.91, and the range of $R^2$ between width and height was 0.79 ? 0.92. As a result of estimating the cross-sections of 6 rivers using the regression equations, the regression equations considering the locations of cross-sections showed better performance both in the cross-sectional area and height estimation than the regression equations estimated using the complete data. Hydrologic Engineering Center - River Analysis System (HEC-RAS) was used to simulate the flood stage analysis of the estimated and the measured cross-sections for 50-year, 100-year, and 200-year frequency floods. As a result of flood stage analysis, the regression equations considering the locations of cross-sections also showed better performance than the regression equations estimated using the complete data. Future research would be needed to consider the factors affecting the cross-sectional shape such as river slope and average flow velocity. This study can be useful for inundation simulation of agricultural land adjacent to an unmeasured stream.

• 농업과학연구
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• 제45권3호
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• pp.521-532
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• 2018

In recent decades, the dry stream phenomena of small and medium sized rivers have been attracting much attention as an important social problem. To prevent dry stream phenomena, it is necessary to build an infrastructure that manages rivers. To accurately determine the progress of dry stream phenomena, it is necessary to continuously measure the discharge and other hydrological factors for small and medium sized rivers. However, until now, the flow data for small and medium rivers in Korea has been insufficient. To overcome the lack of supporting data for supporting rational decision-making in policy and project implementation, a short- and long-term hydrological model was developed that takes into consideration hydrological changes such as the increase of the impervious area due to urban development and groundwater pumping, the construction of a large-scale sewage treatment plant, the maintenance of stream-oriented rivers, etc. In the developed model, the distributed grid is represented by three layers: Surface flow, interflow, and groundwater flow. The surface flow and intermediate flow flowed along the flow direction, and the groundwater flow was calculated by a two-dimensional groundwater analysis model such that the outflow occurred in all directions without a specific flow direction. The effects of land use and cover on evapotranspiration and infiltration and the effects of multiple landscapes can be simulated in the developed model.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.695-700
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• 1999

Stream and groundwater qualities of two rural watershes in the upper North Han river basin were monitored for 14months. Six to eight stream sampling sites and two to there groundwater monitoring wells were chosen and water samples were regularyl collected and analyzed with respect to total nitrogen(T-N), total phosphorus(T-P) and total suspended solids(TSS). Monitoring data were graphically analyzed with respect to time.Rainfall amout and intensity seemed to have an impact on stream T-N and T-P concentration changes. TSS concentrations were generally lower than the first class stream water quality standared, Both stream and groundwater qualities near livesstock feetlot areas were degraded indicating the feedlots have an impact on water quality.

• 농촌계획
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• 제2권2호
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• pp.109-117
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• 1996

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.