• 한국지역지리학회지
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• 제1권1호
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• pp.93-101
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• 1995

라오스 북부에 위치하는 남칸강 유역 분지는 석회암대지(1000m 전후)와 이를 둘러싼 급경사지(700-1000m), 넓은 산록 완사 구릉지(300-700m), 좁은 층적평야로 이루어져 있다. 대지 상에는 아편, 산록완사 구릉지에는 밭벼가 재배되고 있는데 이들 농업은 이동식 화전농업의 형태로 이루어져 삼림과 토양을 황폐시키는 심각한 환경문제를 일으키고 있다. 이 지역의 화전과 살밈의 분포 상태를 계량적으로 파악하고 환경문제를 검토하기 위하여 남칸강의 한소지류인 H.Khane 강 유역분지에 대하여 MOS-1외 위성영상을 분석하고 40지점에 대하여 토양 샘플을 채취하여 토성을 분석하였다. 삼림과 토지이용상태를 분류한 것이 사진 2이고, 이의 고도별 분포면적을 계산한 것이 <표 2>이며, 토성을 분석한 것이 <표 3>이다. 남칸강 유역분지의 과다한 화전활동은 식생적 측면에서 삼림의 면적을 축소시키고 교목위주의 1차림이 관목위주의 2차림으로 바뀌어 가며, 토양적 측면에서 토양침식을 활성화시켜 구릉지 토양은 척박한 산성토양으로 변해가고 있고, 완경사 구릉지면은 우곡(雨谷)(gully)침식에 의하여 심하게 개석된 악지역형(惡地地形)으로 바뀌어가고 있다. 이와 같은 환경문제의 해결을 위해서는 무엇보다도 농업을 정착시키는 것이 급선무이다.

• 한국수자원학회논문집
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• 제46권8호
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• pp.873-884
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• 2013

우리나라는 몬순기후의 영향으로 여름철 강우가 집중되기 때문에 작은 기후변화에도 심각한 수자원의 문제를 야기시킬 수 있다. 이로 인해 기후변화에 대한 많은 관심이 집중되어 그에 따른 연구도 활발히 진행되고 있다. 본 연구는 남강유역에서의 미래 기후변화에 의한 하천의 흐름과 수질변화를 예측하기 위해 유역-하천모형을 연계하여 하고자 하였다. 인공신경망기법을 이용하여 기후시나리오를 예측한 후 유역수문 모형인 SWAT모형을 구축하였고 모형의 적용성 평가를 위해 환경부자료를 이용하여 검보정한 결과 $R^2$이 0.7 이상으로 적정수준으로 모의되었다. SWAT의 결과와 HEC-ResSIM을 이용한 미래 남강댐 방류량을 QUALKO의 입력 자료로 사용하였다. 그 결과 저수기에는 풍수기와는 달리 연도별 유량에 따라 BOD가 많게는 약 2mg/L의 차이를 보이는 등 변화 폭이 크게 나타났다. 강우와 유역의 유출이 하천의 수질에 큰 영향을 끼치기 때문에 풍수기에 비해 유량이 적은 저수기에 수질 농도가 높은 것을 알 수 있다. 그러므로 남강댐의 저수기의 용수확보를 통해 남강하류 하천의 유지용수를 확보하고 효율적인 관리를 통해 향상된 수질을 관리 할 수 있을 것으로 판단된다.

• 한국물환경학회지
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• 제24권4호
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• pp.488-498
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• 2008

Soil and Water Assessment Tool (SWAT) model have been widely used in simulating hydrology and water quality analysis at watershed scale. The SWAT model extracts topographic feature using the Digital Elevation Model (DEM) for hydrology and pollutant generation and transportation within watershed. Use of various DEM cell size in the SWAT leads to different results in extracting topographic feature for each subwatershed. So, it is recommended that model users use very detailed spatial resolution DEM for accurate hydrology analysis and water quality simulation. However, use of high resolution DEM is sometimes difficult to obtain and not efficient because of computer processing capacity and model execution time. Thus, the SWAT Topographic Feature Extraction Error (STOPFEE) Fix module, which can extract topographic feature of high resolution DEM from low resolution and updates SWAT topographic feature automatically, was developed and evaluated in this study. The analysis of average slope vs. DEM cell size revealed that average slope of watershed increases with decrease in DEM cell size, finer resolution of DEM. This falsification of topographic feature with low resolution DEM affects soil erosion and sediment behaviors in the watershed. The annual average sediment for Soyanggang-dam watershed with DEM cell size of 20 m was compared with DEM cell size of 100 m. There was 83.8% difference in simulated sediment without STOPFEE module and 4.4% difference with STOPFEE module applied although the same model input data were used in SWAT run. For Imha-dam watershed, there was 43.4% differences without STOPFEE module and 0.3% difference with STOPFEE module. Thus, the STOPFEE topographic database for Soyanggang-dam watershed was applied for Chungju-dam watershed because its topographic features are similar to Soyanggang-dam watershed. Without the STOPFEE module, there was 98.7% difference in simulated sediment for Chungju-dam watershed for DEM cell size of both 20 m and 100 m. However there was 20.7% difference in simulated sediment with STOPFEE topographic database for Soyanggang-dam watershed. The application results of STOPFEE for three watersheds showed that the STOPFEE module developed in this study is an effective tool to extract topographic feature of high resolution DEM from low resolution DEM. With the STOPFEE module, low-capacity computer can be also used for accurate hydrology and sediment modeling for bigger size watershed with the SWAT. It is deemed that the STOPFEE module database needs to be extended for various watersheds in Korea for wide application and accurate SWAT runs with lower resolution DEM.

• 농촌계획
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• 제7권1호
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• pp.77-88
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• 2001

In order to evaluate the applicability of GWLF model which can efficiently estimate non-point and point source pollutant loadings in rural watershed including urban district, the model was applied to an experimental watershed. The model was calibrated using observed data such as daily runoffs, sediment yields, T-N, and T-P. Simulated daily runoffs and sediment yields by the model using calibrated parameters were in food agreement with the observed data. There were difference between the simulated and observed nutrient loading which was considered resonable. The simulated results by the model showed that T-N, T-P and sediment yields were dependent on the amount of stream runoff discharge and land use. GWLF model is believed to applicable to estimate amount of pollutant loading of non-point source pollution for the water qualify control of agricultural watersheds.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2003년도 학술발표논문집
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• pp.467-470
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• 2003

The size, scale, and number of subwatersheds can affect a watershed modeling process and subsequent results. The objective of this study was to determine the appropriate level of subwatershed division for simulating streamflow. The Soil and Water Assessment Tool(SWAT) model with a GIS interface(BASINS SWAT) was applied to Yongdam Dam watershed. Daily output was analyzed from simulation, which was executed for 10 years using climate data representing the 1987 to 1996 period. The optimal number of subwatersheds and HRUs to adequately predict streamflow was found to be around 15, 174. Increasing the number of subwatersheds and HRUs beyond this level does not significantly affect the computed streamflow. this number of subwatersheds and HRUs can be used to optimize SWAT input data preparation requirements and simplify the interpretation of results without compromising simulation accuracy.

• 한국환경과학회지
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• 제22권5호
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• pp.523-531
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• 2013

In this study, a method of simulating ephemeral stream runoff characteristics in Jeju watershed is newly suggested. The process based conceptual-physical scheme is established based on the SWAT-K and applied to Cheonmi-cheon watershed which shows the typical pattern of ephemeral stream runoff characteristics. For the proper simulation of this runoff, the intermediate flow and baseflow are controlled to make downward percolation should be dominant. The result showed that surface runoff simulated by using the modified scheme showed good agreement with observed runoff data. In addition, it was found that the estimated runoff directly affected the groundwater recharge rate. This conceptual model should be continuously progressed including rainfall interception, spatially estimated evapotranspiration and so forth for the reasonable simulation of the hydrologic characteristics in Jeju island.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2012년도 하계학술대회
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• pp.71-74
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• 2012

본 논문에서는 새로운 문자 분할 알고리즘을 제안한다. 고전적인 문자 분할 알고리즘은 학술적인 문서영상과 같이 단순한 구조를 가진 문서영상을 대상으로 하여 좋은 성능을 보였지만 다양한 문자 크기와 색상, 그림, 복잡한 배경 등으로 구성된 문서영상에서는 좋지 못한 성능을 보인다. 최근에 제안고 있는 방법들은 복잡한 문서영상에서도 좋은 성능을 보이도록 다양한 기법들을 적용하여 우수한 성능을 보이고 있지만, 대부분의 방법들이 영상을 일정한 크기의 블록으로 나누어 문자분할을 하기 때문에 세밀한 부분에서는 성능이 어느 정도 한계를 보인다. 따라서 본 논문에서는 블록의 크기에 제한을 갖지 않는 새로운 방법으로서, watershed 알고리즘을 이용한 문자분할 방법을 제시한다. 구체적으로, watershed 알고리즘을 이용하여 문서영상의 구조(docstrum)를 파악하고 이를 기반으로 문자를 분할한다. 제안하는 방법은 크게 엣지 검출, distance transform, watershed 알고리즘을 이용한 docstrum 분석, 문자 분할의 네 단계를 거친다. 실험 결과 블록에 기반한 기존의 방법들이 놓치는 세밀한 부분에서도 제안된 알고리즘은 올바른 분할결과를 얻을 수 있음을 확인하였다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2005년도 학술발표회(2)
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• pp.1333-1334
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• 2005

• 한국환경과학회지
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• 제20권10호
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• pp.1347-1355
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• 2011

In Jeju island, runoff has frequently happened when the rainfall depth is over a threshold value. To simulated this characteristic rainfall-runoff model structure has to be modified. In this study, the TRSM (Threshold Runoff Simulation Method) was developed to overcome the limitations of SWAT in applying to the hydrologic characteristics of Jeju island. When the precipitation and soil water are less than threshold value, we revised the SWAT routine not to make surface/lateral or groundwater discharge. For Hancheon watershed, the threshold value was set as 80% of soil water through the analysis of rainfall-runoff relationship. Through the simulation of test watershed, it was proven that TRSM performed much better in simulating pulse type stream flow for the Hancheon watershed.

• 한국농공학회논문집
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• 제54권4호
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• pp.55-63
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• 2012

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.