• 한국환경교육학회지:환경교육
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• 제19권3호
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• pp.150-164
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• 2006

This study reviewed a recently developed environmental education model 'ENVISION' and analyzed the value of the ENVISION program with environmental education(EE) perspective. Also this study proposed a prototype model of a inquiry-based water environmental education model with watershed concepts as a result of discussion of tills research. In the review of ENVISION, this research followed the theoretical framework of 'Inquiry-Based EE' that was previously proposed by the author. The ENVISION was characterized in tills research as two directions: watershed and scientific inquiry. Tills research argued that the watershed concept has a potentially very good meaning in EE because watershed enables 'holistic' view in EE area, and that the scientific inquiry in ENVISION seeks evidence-based explanation about local watershed environmental problems. That belongs to the scientific inquiry, which is also 'Inquiry-Based EE' and has internal value under EE perspective. Finally, this research proposed a prototype EE model that is about watershed concept, and is based on inquiry as general sense (scientific and insightful inquiries) and 'Environmental Studies for EE, (ESEE)' as the inquiry directions. The proposed model can be said a combination of the watershed concept and inquiry-based EE, and it seems that the model materializes better the EE nature than the ENVISION model.

• JSTS:Journal of Semiconductor Technology and Science
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• 제12권2호
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• pp.175-185
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• 2012

Predictive watershed transform is a popular object segmentation algorithm which achieves a speed-up by identifying image regions that are different from the previous frame and performing object segmentation only for those regions. However, incorrect segmentation is often generated by the predictive watershed transform which uses only local information in merge-split decision on boundary regions. This paper improves the predictive watershed transform to increase the accuracy of segmentation results by using the additional information about the root of boundary regions. Furthermore, the proposed algorithm is processed in a block-based manner such that an image frame is decomposed into blocks and each block is processed independently of the other blocks. The block-based approach makes it easy to implement the algorithm in hardware and also permits an extension for parallel execution. Experimental results show that the proposed watershed transform produces more accurate segmentation results than the predictive watershed transform.

• 한국농공학회논문집
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• 제49권5호
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• pp.81-90
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• 2007

Watershed topographical information is required in hydrologic analysis, supporting efficient hydrologic model operation and managing water resources. Watershed topographical data extraction systems based on desktop GIS are abundant these days placing burdens for spatial data processing on users. This paper describes development of a Web-based Geographic Information Systems that can delineate the Geum River sub-basins and extract watershed topographical data in real time. Through this system, users can obtain a watershed boundary by selecting outlet location and then extracting topographical data including watershed area, boundary length, average altitude, slope distribution about the elevation range with Web browsers. Moreover, the system provides watershed hydrological data including land use, soil types, soil drainage conditions, and NRCS(Natural Resources Conservation Service) curve number for hydrologic model operation through grid overlay technique. The system operability was evaluated with the hydrological data of WAMIS(Water Management Information System) with the government operation Web site as reference data.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.82-84
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• 2003

Watershed boundaries and flow paths within the watershed are the most important factors required in watershed analysis. Most often the derivation of watershed boundaries and stream network and flow paths is based on topographical maps but spatial variation of flow direction is not clearly understandable using this method. Water resources projects currently use 1: 50, 000-scale ground survey or aerial photography-based topographical maps to derive watershed boundary and stream network. In basins, where these maps are not available or not accessible it creates a real barrier to watershed geo-spatial analysis. Such situations require the use of global datasets, like GTOPO30. Global data sets like ETOPO5, GTOPO30 are the only data sets, which can be used to derive basin boundaries and stream network and other terrain variations like slope aspects and flow direction and flow accumulation of the watershed in the absence of topographic maps. Approximately 1-km grid-based GTOPO 30 data sets can derive better outputs for larger basins, but they fail in flat areas like the Karkheh basin in Iran and the Amudarya in Uzbekistan. A new window in geo-spatial hydrology has opened after the launching of the space-borne satellite stereo pair of the Terra ASTER sensor. ASTER data sets are available at very low cost for most areas of the world and global coverage is expected within the next four years. The DEM generated from ASTER data has a reasonably good accuracy, which can be used effectively for hydrology application, even in small basins. This paper demonstrates the use of stereo pairs in the generation of ASTER DEMs, the application of ASTER DEM for watershed boundary delineation, sub-watershed delineation and explores the possibility of understanding the drainage flow paths in irrigation command areas. All the ASTER derived products were compared with GTOPO and 1:50,000-based topographic map products and this comparison showed that ASTER stereo pairs can derive very good data sets for all the basins with good spatial variation, which are equal in quality to 1:50,000 scale maps-based products.

• 한국농공학회논문집
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• 제51권5호
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• pp.69-78
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• 2009

In order to improve water quality of upper watershed of Paldang reservoir, it is necessary to evaluate non-point source pollution loads and identify critical watershed pollution sources. A GIS based Soil and Water Assessment Tool was applied to evaluate model application and reliability, estimate NPS pollution load, identify critical watershed by NPS pollution sources, and suggest various best management practices for Kyongan Stream watershed. Yearly NPS pollution loads were estimated 30.0% SS, 60.1% TN and 35.4% TP, respectably. The watershed pollution load is mainly decided by precipitation condition and SS and nutrients load have a significant regression relationship. Based on 10-year average yearly NPS pollution load, critical sub-watersheds were identified. The No. 5 and 17 which have lots of relatively intensive agricultural fields and scattered industrial area were vary critical sub-watersheds and under more intensive pollution load. In order to control critical watershed, watershed best management practices such as scientific fertilizer, contour farming and parallel terrace, transferring the sloppy farmland to grass or forest and constructing a buffer zone, and constructing wetlands and retention ponds will be applied. Overall the SWAT model can be efficiently used for identification of critical sub-watersheds in order to develop a priority watershed management plan to reduce water pollutions.

• 한국물환경학회지
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• 제28권6호
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• pp.819-832
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• 2012

HSPF model based on BASINS was applied for the Hwaseong Reservoir watershed (HRW) to evaluate the feasibility of water quality management. The watershed was divided into 45 sub-basins considering various watershed environment. Streamflow was calibrated based on the measured meteorological data, discharge data of treatment plants and observed streamflow data for 2010 year. Then the model was calibrated against the field measurements of water qualities, including BOD, T-N and T-P. In most cases, there were reasonable agreements between observed and predicted data. The validated model was used to analyze the characterization of pollutant load from study area. As a result, Non-point source pollutant loads during the rainy season was about 66~78% of total loads. In rainy-season, water quality parameters depended on precipitation and pollutant loads patterns, but their concentration were not necessarily high during the rainy season, and showed a decreasing trend with increasing water flow. As another result of evaluation for load duration curves, in order to improve water qualities to the satisfactory level, the watershed managements considering both time-variant and pollution sources must be required in the HRW. Overall, it was found that the model could be used conveniently to assess watershed characteristics and pollutant loads in watershed scale.

• 한국안전학회지
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• 제29권1호
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• pp.31-36
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• 2014

In this study, the methodologies for evaluating the low-flow at the ungauged watershed are reviewed and assessed. The ungauged watershed can be classified into different situations such as the partially recorded watershed and the completely ungauged watershed. The extension method and the percentile method are used to evaluated the low-flow at the partially recorded watershed. The drainage-area ratio method and the regional regression method are used at the completely ungauged watershed. These four methods are applied and validated based on the hydrological and geometric data acquired from unit watersheds in Han River basin for TMDLs. In case of partially recorded watershed, the values of low-flow evaluated by the extension method are in better agreement with measured flow-rate rather than those by the percentile method. In case of completely ungauged watershed, the drainage-area method is broadly used to estimate the low-flow. It must be paid attention to consider the treated sewage discharge produced at watersheds when applying the method.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(3)
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• pp.59-62
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• 2002

Watershed Segmentation with Multiple Merging Conditions in Region Growing Process The watershed segmentation method holds the merits of edge-based and region-based methods together, but still shows some problems such as over segmentation and merging fault. We propose an algorithm which overcomes the problems of the watershed method and shows efficient performance for .general images, not for specific ones. The algorithm segments or merges regions by thresholding the depths of the catchment basins, the similarities and the sizes of the regions. The experimental results shows the reduction of the number of the segmented regions that are suitable to human visual system and consciousness.

• 한국농공학회논문집
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• 제51권6호
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• pp.1-9
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• 2009

Watershed topographical data is essential for the management for water resources and watershed management in terms of hydrology analysis. Collecting watershed topographical and meteorological data is the first step for simulating hydrological models and calculating hydrological components. This study describes a specialized Web-based Geographic Information Systems, Soil Water Assessment Tool model data generation system, which was developed to support SWAT model operation using Web-GIS capability for map browsing, online watershed delineation and topographical and meteorological data extraction. This system tested its operability extracting watershed topographical and meteorological data in real time and the extracted spatial and weather data were seamlessly imported to ArcSWAT system demonstrating its usability. The Web-GIS would be useful to users who are willing to operate SWAT models for the various watershed management purposes in terms of spatial and weather preparing.

• 한국지리정보학회지
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• 제10권4호
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• pp.22-34
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• 2007

우리나라는 그 동안 국토를 이용하고 관리함에 있어 생태적 계획에 입각한 지속가능한 보전 및 관리보다는 효율성과 경제성을 중심으로 한 개발지향적 논리에 초점을 맞춤으로써 국토 환경보전에 커다란 기여를 하고 있는 농경지 및 산지면적이 지속적으로 감소하고 있는 추세이다. 지역생태계의 가치에 대한 생태학적 인식이 부족한 가운데 이루어진 일련의 지속적인 개발압력은 자연환경의 자정능력을 초과하는 환경압력으로 작용함에 따라 지역생태계의 건전한 물질순환과 에너지 흐름에 부정적인 결과를 초래하고 있다. 이에 본 연구에서는 기존의 물환경 문제해결을 위한 공간단위로서의 유역개념이 아닌 생태계를 평가하고 관리할 수 있는 공간 단위개념으로서 유역을 분석하기 위하여 다양한 경관요소가 혼재하고 있는 낙동강 유역권을 대상으로 경관구성 요소 중 토지이용을 중심으로 공간분석기법을 활용하여 서로 유사한 패턴을 보이는 유형으로 분류하고, 각 유형별 지역에 대한 특징을 분석하였다.