• 한국토양비료학회지
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• 제46권6호
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• pp.417-425
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• 2013

This study investigated the runoff from rice paddy located on reclaimed fine sandy loam soil to provide data for the development of policies to protect water quality of estuaries. Total N (TN), Total P (TP) concentrations and runoff loads at outlet were monitored from 2006 to 2008. Soil phosphate adsorptivity was measured and compared with typical paddy soil in watersheds. TP concentration of the paddy water and TP runoff loads were much greater than those of typical paddy field in watershed because phosphate adsoptivity in reclaimed paddy field of fine sandy loam appeared to be a third of those of typical paddy soils by relatively low soil OM and high sand content of the reclaimed soil. Thus, nutrient runoff, particularly phosphate from the reclaimed paddy field needs to be managed more thoroughly to protect estuarine water quality.

• 한국물환경학회지
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• 제24권4호
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• pp.473-479
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• 2008

Environment problem has been arising in many countries. Especially, soil erosion has been deemed as one of the biggest issues because sediment causes muddy water and pollutants, such as agricultural chemicals, flow in the stream with this sediment. Many studies, regarding soil loss and non-point source pollution from watershed, has been performed while serious problem has been known. Soil loss occurred in most agricultural area by rainfall and runoff. It makes hydraulic structure unstable, causes environmental economical problems because muddy water destroys ecosystem and causes intake water deterioration. As revealing serious effects of muddy water by sediment, many researches have been doing with various methods. Hydraulic structures establishments such as soil erosion control dams and grit chamber are common. Vegetative filter strip is investigated in this study because vegetative filter strip is designed for reducing sediment from upland areas of the watershed, and it has many functions, not only sediment reduction but also runoff water quality improvement and wildlife habitat. With these positive functions of the vegetative filter strip, the study about vegetative filter strip has been increasing for reducing sediment because it is more effective than hydraulic structures from an environmental perspective. But the sediment trapping efficiency by vegetative filter strip, needs to be investigated and designed first. Therefore the model, VFSMOD-W, was used in this study as it can estimate sediment trapping efficiency of vegetative filter strip under various field, vegetation, weather condition. Sensitive factors to sediment trapping efficiency are studied with VFSMOD-W, and sediment trapping efficiency equation has been derived using two most sensitive factors. It is thought that the equation suggested in this study can be used in Soil and Water Assessment Tool (SWAT), to overcome the limit of SWAT filter strip module, which is based solely on filter strip width.

• 한국물환경학회지
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• 제38권5호
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• pp.220-230
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• 2022

Seasonal variability of water quality in the upland headwater streams in ten forested catchments (37.0~209.0 ha) was examined from April to November 2021. Here, seven physicochemical parameters were analyzed including pH, electrical conductivity (EC), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen (T-N), total phosphorous (T-P), and BOD/TOC. The parameters were compared with those of lowerland rivers as middle and lower reaches within a watershed. The pH showed was low (6.4~6.9) during all the seasons, however, BOD and BOD/TOC in the fall season were 2-fold higher than in the spring and summer seasons. Based on environmental standards, the water quality level revealed that the upland headwater streams maintained the purity and cleanliness of water except for pH in the summer season. BOD/TOC of all the seasons and BOD of the fall season in the upland headwater streams were higher than that in the lowerland rivers, whereas the rest of the physicochemical parameters in the upland headwater streams were lower than that in the lowerland rivers. Additionally, the water quality level maintained the purity and cleanliness of water as "Good" in two reaches. The unique aspects of our study design enabled us to draw inferences about water quality characteristics with temporal and spatial analysis in upland headwater streams. This design will be useful for the long-term strategy of effective water quality management for integrated upland headwater streams and lowerland rivers within a watershed.

• 한국농림기상학회지
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• 제25권4호
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• pp.404-414
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• 2023

본 연구에서는 미래 SSP 기후변화 시나리오 자료를 생산하기 위해 과거 30년(1981-2010)에 대한 한반도 농업용 전자기후도를 생산하고 평가하였다. ERA5 재분석 자료와 기상청 ASOS 자료에 지형인자를 고려하는 IGISRM 통계 모형을 이용하여 기후요소 6종(강수량, 평균기온, 최고기온, 최저기온 풍속, 상대습도, 일사량)에 대한 1km 해상도의 격자형 상세자료를 생산하였다. 연 평균(누적) 분포도를 살펴본 결과, 모든 변수는 기상청 ASOS 관측에서 나타난 일반적인 특성을 잘 모의하면서 지형적 효과가 적절하게 반영되었다. 농진청 농업기상 AWS와 기상청 방재기상 AWS를 이용하여 상관계수, Slope, NRMSE를 계산한 결과, 기온관련 변수에서는 재현성이 우수하게 나타났으며, 그 외 변수에서는 재현성이 다소 낮고 지역적 편차가 큰 것으로 나타났다. 관측정보 기반의 농업용 전자기후도는 미래 SSP 기후변화 시나리오 자료를 상세화하는데 기본 자료로 활용될 것이다.

• 한국물환경학회지
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• 제32권6호
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• pp.552-561
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• 2016

For the prediction of hydrologic phenomenon, predicting future land use change is a very important task. This study aimed to compare and analyze the two land use change models, CLUE-S and SLEUTH3-R. The analysis of two models were performed based on the MSR value such that the model with more reliable MSR value can be recommended as an appropriate land use change prediction model. The model performance was examined by applying to the Gapcheon A watershed. Land use map of the study area of 2007 obtained from the Ministry of Environment was compared with the predicted land use map obtained from each of the two models. The result from both models showed somewhat similar results. The MSR value obtained from CLUE-S was 0.564, while that from SLEUTH3-R was 0.586. However, when land use map of 2010 was compared with predicted land use map obtained from the two models in same manner, the MSR value obtained from CLUE-S' was 0.500 while that from SLEUTH3-R was decreased to 0.397, an approximately 32.3% decrease from previous value of 2007. Moreover, SLEUTH3-R showed more sensitivity in conversion of urban areas, as compared to other land use types. Therefore, for the prediction of future land use change, CLUE-S model is more reliable than SLEUTH3-R.

• 한국물환경학회지
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• 제23권6호
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• pp.934-944
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• 2007

Fine suspended solids (SS) induced into a reservoir after flood events play important ecological and water quality roles by presenting persistent turbidity and attenuating light. Thus the origin and physical features must be characterized to understand their transport processes and associated impacts, and for the establishment of watershed based prevention strategies. This study was aimed to characterize the physical properties of the SS sampled from Daecheong Reservoir and its upstream rivers during flood events. Extensive field and laboratory experiments were carried out to identify the turbidity-SS relationships, particle size distributions, settling velocity, and mineral compositions of the SS. Results showed that the turbidity-SS relationships are site-specific depending on the locations and flood events in the system. The turbidity measured within the reservoir was much greater than that measured in the upstream rivers for the same SS value. The effective diameters ($D_{50}$) in the rivers were in the range of $13.3{\sim}54.3{\mu}m$, while those in the reservoir were reduced to $2.5{\sim}14.0{\mu}m$ due to a fast settling of large particles in the rivers. The major minerals consisting of the SS were found to be Illite, Muscovite, Albite, and Quartz both in the rivers and reservoir. Their apparent settling velocities at various locations in the reservoir were in the range of 0.06~0.13 m/day. The research outcome provides a fundamental information for the fine suspended particles that cause persistent turbidity in the reservoir, and can be used as basic parameters for modeling study to search watershed based optimal control measures.

• 환경영향평가
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• 제18권5호
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• pp.281-291
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• 2009

In Total Water Pollutant Load Management System of Korea, unit load approach based on land register data is currently used for the estimation of non-point pollutant load. However, a problem raised that land register data could not always reflect the actual land surface coverages which determine runoff characteristics of non-point pollution sources. As a way to overcome this, we tried to establish quantitative relationships between the aerial images (0.4m resolution) which reflect actual land surface coverages and the land registration maps according to the 19 major designated land-use categories in Kyeongan watershed. Analyses showed different relationships according to the land-use categories. Only a few land-use categories including forestry, road and river showed essentially identical and some categories such as orchard, parking lot and sport utility site showed no relationships at all between image data and land register data. Except for the two cases, all the other categories showed statistically significant linear relationships between image data and land register data. The analyses indicate that using high resolution aerial maps is a better way to estimate non-point pollutant load. If the aerial maps are not available, application of the linear relationships as conversion factors of land register data to image data could be an possible option to estimate non-point pollutant loads for the specific land-use categories in Kyeongan watershed.

• 한국물환경학회지
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• 제32권2호
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• pp.135-141
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• 2016

This study investigated changes of hydrology, soil characteristics, riparian vegetation communities, and geomorphology in sandbars before and after sand-mining to determine the effect of sand-mining at upstream of Guemgang and Bochungcheon streams in Korea. Sand-mining events affected the mining area. They supplied organic matters and nutrients during flood. Sediment deposition caused soil texture change and expansion of vegetation area. However, riverbeds were stabilized after the disturbance. According to the analyses of aerial photographs, the vegetation area was significantly expanded in both dam-regulated streams and dam-unregulated streams after sand-mining. Willow shrubs advanced in disturbed area at an average of 10 years after sand-mining. It took willows trees 10.6 years to become dominant communities. Therefore, it took a total of 20.6 years for new riparian forest to form in sandbar after sand-mining. Our results confirmed that stream flow condition were dependent on vegetation recruitment in dam-regulated streams and dam-unregulated streams. For willow recruitment in unregulated streams, calculation of water level below dimensionless bed shear stress is important because low water level variation is a limiting factor of vegetation recruitment.

• 한국지리정보학회지
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• 제25권4호
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• pp.19-31
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• 2022

우리나라 도시숲은 「도시숲 등의 조성 및 관리에 관한 법률」에 의거하여 자연공원을 제외한 모든 산림과 수목으로 정의되고 있으나, 일반적인 인식으로서의 도시 내 존재하는 숲의 개념과는 이질성이 있다. 본 연구에서는 도시숲을 "도시 내에 존재하는 산림과 수목"으로 규정하였으며, 도시의 경계를 설정하기 위한 시나리오를 제안하고 그에 따른 도시숲의 면적 변화를 모의하였다. 법률상 도시지역의 정의, WHO에서 제안한 주거지로부터 도시숲에 접근 가능한 거리(300m), 산림유역을 고려한 네 가지 시나리오를 설정하여 각 시나리오에 따라 도시숲의 양적 분포를 분석하였다. 첫 번째로 "용도지역상 도시지역"의 최외곽 경계와 연접하는 산림유역까지를 도시숲 경계로 규정한 경우, 도시숲 면적은 약 183만ha, 1인당 도시숲 면적은 약 386㎡로 분석되었다. 두 번째로 "용도지역상 도시지역"의 최외곽 경계로부터 300m 이내까지 도시로 규정하고 해당 경계와 연접한 산림유역 내에 존재하는 숲을 도시숲으로 규정한 경우, 도시숲 면적은 약 192만ha, 1인당 도시숲 면적은 약 405㎡로 분석되었다. 세 번째로 "행정구역 상 읍·동 지역"내 "용도지역상 도시지역"의 최외곽 경계와 연접하는 산림유역까지를 도시숲 경계로 규정한 경우, 도시숲 면적은 약 108만ha, 1인당 도시숲 면적은 약 230㎡로 분석되었다. 네 번째로 "행정구역 상 읍·동 지역" 내 "용도지역상 도시지역"의 최외곽으로부터 300m 경계와 연접하는 산림유역까지를 도시로 규정한 경우, 도시숲 면적은 약 120만ha, 1인당 도시숲 면적은 약 256㎡로 분석되었다. 이렇듯 도시의 정의에 따라 도시숲의 면적이 다양하게 추정될 수 있기 때문에, 국가통계를 집계하기 위해서는 도시에 대한 정의가 먼저 정립되어야 하고, 그에 따라 현실적·과학적 분석에 근거하여 도시숲의 면적이 산출되어야 한다.

• 한국수자원학회논문집
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• 제33권6호
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• pp.689-699
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• 2000

본 논문에서는 홍수유출의 해석·예측을 위한 홍수추적 모형으로서 현재 국내에서 널리 이용되고 있는 저류함수모형을 개선하였다. 유출 해석의 정확성에 가장 큰 영향을 미치는 요인 중의 하나인 매개변수 산정에 최적화기법을 도입하여 기존의 경험식 등에 의한 매개변수 결정의 비객관성을 개선하였으며, 결정된 매개변수들을 시변성으로 취급하고 이의 실시간 자동보정에 퍼지제어를 사용하여 시간에 따른 유역의 변동 특성에 적절히 대응 할 수 있도록 하였다. 또한 홍수유출 해석시 가장 까다로운 문제점 중의 하나인 잔유역 유입량의 처리를 위하여 유역모형과 하도모형을 하나의 단일모형으로 하는 통합저류함수모형을 제안하였다.