• 한국환경과학회지
• /
• 제31권9호
• /
• pp.757-766
• /
• 2022

This study is to examine how well the hydrologic model reproduces the dam collapse. To do this, A hydrologic model FLO-2D is being operated to reproduce dam collapse with rainfall data and surface data in a small dam. In order to examine the performance of the model, the simulation was compared and reviewed with the data collected through the field survey. The results show that it takes about 2 hours to reach 1 km downstream. Inundation areas are about 188,640 m2 by the simulation and the difference from the field investigation is about 6.1%. Ten representative points were selected from the areas where the simulation and the field survey did not match. The discrepancy is less than about 0.08 m and does not appear to be significant. This study will present basic information on disaster preparedness operation and planning to minimize damage caused by sudden collapse of agricultural soil dams in the future.

• Ecology and Resilient Infrastructure
• /
• 제3권1호
• /
• pp.54-61
• /
• 2016

미국의 수질교환법의 제정 이후 이 법안의 적용을 위하여 많은 파일럿 프로그램과 프로젝트가 생성되었으나 실제로 수질교환이 이루어 지는 경우는 흔치 않은 현실이다. 수질교환법의 적용이 용이하지 않은 이유로 가장 큰 것은 교환 지역 양측간의 공정성을 확보하기가 쉽지 않기 때문이다. 또한 도시개발로 유발되는 비점오염원의 유출량으로 인한 하천의 환경영향의 불확실성이 정책입안자의 법안 적용을 더욱 어렵게 하고 있다. 본 논문은 수질 모델링 프로그램 중 도시의 불투수면의 유출을 모의하기에 유용한 Hydrological Simulation Program-Fortran (HSPF)을 이용하여 미래의 도시개발 시나리오에 대응하는 점오염과 비점오염원 유출량을 도출하였다. 도시개발의 정도와 강우강도에 따른 부유탁도의 증가분을 계산 함으로써 향후 도시개발이 미치는 수질 영향을 하천 상 하류 간의 수질교환 단위로 전환하여 제시하였다. 제시된 지역 특화된 수질교환단위는 정책입안자와 이해관계자들에게 수질교환법 적용을 위한 정책결정 시스템으로 사용될 수 있다.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
• /
• pp.167-174
• /
• 2004

Several metalliferous and coal mines, including Myungjin, Seojin and Okdong located at the upper watershed of Okdong stream, were abandoned or closed since 1988 due to the mining industry promotion policy and thus disposed an enormous amount of mining wastes without a proper treatment facilities, resulting in water pollution in the downstream areas. AMD and waste effluents from the closed coal mines were very strongly acidic showing pH ranges of 2.7 to 4.5 and had a high level of total dissolved solid (TDS) showing the ranges of 1,030 to 1,947 mg/L. Also heavy metal concentrations in these samples such as Fe, Cu, Cd and anion such as sulfate were very high. These parameters of AMD and effluents were considered to be highly polluted as compared to those in the main stream area of the Okdong river and be major pollutants for water and soil in tile downstream area. Pollution indices of the surface water at the upper stream of Okdong river where AMD of the abandoned coal mines was flowed into main stream were in the ranges of 16.3 to 47.1. On the other hand, those at the mid stream where effluents from tailing dams and coal mines flowed into main stream were in tile ranges of 10.6 to 19.5. However, those at the lower stream were ranged from 10.6 to 14.9 These results indicated that mining wastes such as AMD and effluents from the closed mines were tile major source to water pollution at the Okdong stream areas.

• 자원환경지질
• /
• 제28권3호
• /
• pp.221-229
• /
• 1995

The heavy metal contents and their dispersion patterns in stream water, stream sediments, land plants and aquatic larvae collected from the hydrologic system flowing via the wasted ore dump of the Moak Au-Ag mine were investigated systematically in order to evaluate the environmental impacts of the abandoned metal mine. The heavy metal content increases abruptly in the vicinity of the wasted ore dump, then attenuated with increasing distance from the mine area. Attenuating rates were stream water > stream sediments > land plants > aquatic larvae. On the other hand, the cumulative content of heavy metals was stream sediments >aquatic larvae > land plants > stream water. Each element tends to be enriched selectively according to media; Zn > Cu > Cd > Pb in stream water, Zn > Pb > Cu > Cd in stream sediments and land plants, and Zn > Cu > Pb > Cd in aquatic larvae. These results show that the degree of enrichment and dispersion of pollutant extruded from the wasted ore dump are different according to elements and media, and that the circulation system of materials of each medium is different. The heavy metals, especially Cu, Pb and Zn, of polluted downstream sediments occur in high proportions of Fe-Mn oxides and organic bounded forms, which show high potential of a secondary pollution source. The content of heavy metals and their dispersion patterns in stream sediments are different from those of ten years ago; pollution levels of heavy metals were degraded in various ranges. The Zn and Cu-polluted areas were widened whereas Fe and Pb-polluted areas were reduced. In crops collected from the farm lands in downstream area, the pepper was more concentrated in all heavy metal than rice. The pepper showed some contaminated level in Cu(9.7ppm) and Zn(149ppm), and the rice in Zn(90ppm). However, both crops showed no significant level in Cd(<0.2ppm) and Pb(<0.5ppm).

• 한국수자원학회논문집
• /
• 제41권12호
• /
• pp.1163-1172
• /
• 2008

본 연구는 댐 건설 전 후 항공사진을 활용하여 댐 하류하천의 사주와 식생의 면적변화, 변화지수, 변화정도와 경년변화를 비교 분석 하였다. 사주면적 변화를 분석한 결과, 댐 건설전의 사주면적은 하천면적의 38 %이었으나, 댐 건설후에는 21 %로 17 %가 감소하였으며, 변화지수는 $-0.9921{\sim}2.9528$ 이었다. 식생면적 변화를 분석한 결과, 댐 건설전의 식생면적은 하천면적의 11 %이었으나, 댐 건설후에 24 %로 13 %가 증가하였으며, 변화지수는 $-0.8908{\sim}12.0736$ 이었다. 안동댐, 임하댐, 합천댐의 사주와 식생의 경년변화를 분석한 결과, 사주면적은 연 $42,600m^2$씩 감소 하였으나 식생면적은 연 $51,700m^2$ 씩 증가하여, 사주면적의 감소 보다 식생면적의 증가가 큰 것으로 분석되었다.

• 생태와환경
• /
• 제43권1호
• /
• pp.117-128
• /
• 2010

본 연구는 2008년 5월부터 2009년 2월까지 양양의 남대천, 강릉의 연곡천과 사천천의 이화학적 수질, 영양단계 및 부착규조를 이용한 생물학적 수질평가를 실시하였다. 남대천, 사천천 및 연곡천의 이화학적 수질은 일부 공사구간 및 하류 정점을 제외하고, BOD가 $2mg\;L^{-1}$ 이하의 농도로 대체적으로 양호한 것으로 나타났으며, 하류정점의 경우 남대천과 사천천이 해수에 의한 염도의 영향과 폐쇄하구의 특성상 영양염의 농축 등 오염이 진행되고 있는 것으로 나타났다. 영양단계 판정결과 남대천은 전지점이 대체적으로 중영양단계를 나타내며, 연곡천은 상류에서 하류로 갈수록 부영양화가 진행되고, 사천천은 전체적으로 부영양단계로 나타났다. 영양단계의 판정은 각 정점간의 결과와 영양염의 유엽 정점을 잘 반영하고 있으나, 강우 및 유량의 변화로 계절별 영양단계는 큰 차이를 나타냈다. 생물학적 수질평가 결과, 남대천은 하류 정점을 제외하고 $\beta\sim\alpha$-빈부수성 이고, TDI는 50 이하로 생물학적 수질이 대체로 양호한 것으로 나타났으며, 일부 공사구간과 하류정점은 $\beta$-중부수성이며, TDI는 70 이상으후 생물학적 수질이 다소 오염된 것으로 나타났다. 연곡천은 $\beta\sim\alpha$-빈부수성이며, TDI는 40 이하로 대체적으로 생물학적 수질이 양호한 것으로 나타났으며, 사천천은 2008년 5월과 2009년 2월의 상류정점을 제외하고 $\beta\sim\alpha$-중부수성 이며, TDI는 70 이상으로 오염된 것으로 나타났다. 상관분석 결과, 생물학적 수질평가 지수인 DAIpo와 TDI 간에 높은 상관성을 나타냈다. 또한 규조지수인 DAIpo와 TDI는 BOD보다 수질 영 양단계(TSI)와 상관성이 높은 것으로 나타났다.

• Journal of Species Research
• /
• 제5권1호
• /
• pp.157-165
• /
• 2016

The hyporheic zone is an ecologically important area for investigating habitat biodiversity. However, only few studies have been conducted on this aspect in Korea. This study aimed to investigate the distribution of arthropod communities in the hyporheic zone of Nakdonggang River between 2012 and 2013. The meiobenthic arthropod communities found in the hyporheic zone were identified using a stereomicroscope and classified into 9 taxanomic groups. The abundance of arthropod communities was higher in the hyporheic zones of streams having well-formed sandbanks and gravelly areas. The arthropod communities found along the Nakdonggang River differed depending on the conditions of levees and the regions of the river from where they were collected. The frequency of species of the order Harpacticoida was high in the Nakdonggang main stream and western downstream region. The abundance of species belonging to Cyclopidae was high in the upstream region, midstream region, and eastern downstream region of the river. The frequency of species of the order Bathynellacea was high in the riverside parks or cement levees, but that of species belonging to Cyclopidae was high in the natural levees and gabion levees. Our findings suggested that arthropod communities preferred natural levees.

• 한국환경보건학회지
• /
• 제16권2호
• /
• pp.83-87
• /
• 1990

This study was carried out to investigate the pollution of heavy metals in soil of seven stations from the upper spot (Yeungchun Dam) of Kumho River to the downstream(Gangchang Bridge). The results obtained were as follows: 1. The content of heavy metals in soil of Kumho River basin was highest at Gangchang Bridge [expresed in $\mu$g/g : Mn(246.0), Cd(1.90), Fe(551.2), Cu(108.2), Zn(86.4), Cr(80.2), respectively]. Whereas, the content of heavy metals expect for Mn, Cu was lowest at Yeungchun Dam [Cd(0.40), Fe(548.0), Zn(30.7), Cr(6.2), respectively] Also, the content of Cr, Zn was increased when the sampling areas are changed from upstream to downstream except for Hayang Bridge, and Hayang Bridge was the diverging point of the heavy metals content. 2. There were relatively correlated between Mn : FE, Cu, Zn, Cr, Fe : Cu, Zn, Cr(0.40 < $\left$\mid${r}\right$\mid$$ < 0.70), and were high correlated between Cd : Mn, Fe, Cu, Zn, Cu : Zn, Zn : Cr(0.70 < $\left$\mid${r}\right$\mid$$ < 0.90). Particularly, there was higest correlated between Cd : Cr, Cu : Cr(0.90< $\left$\mid${r}\right$\mid$$ < 1.0)

• 한국농공학회논문집
• /
• 제55권4호
• /
• pp.83-93
• /
• 2013

Annual average precipitation of Korea is 1,277 mm and around 2/3 of annual precipitation and 74 % of available water resources occurred during monsoon period. In recent years, many agricultural reservoirs have been heightened to increase flood control capacity, reduce flooding damage at downstream areas, and provide sustainable environmental flow during drought period. Thus in this study, the flood control effects of heightening of reservoir banks were simulated with HEC-ResSim and HEC-RAS models. These modes were applied to Bonghak reservoir and it was found that flood control effects were 3~4.5 % with 7 -m heightening. Also, with proper operation (1 m lower of full water level) of reservoir right before the monsoon period, flooding at downstream could be prevented even with design storm of 80 -year recurrence interval. As shown in this study, heightening of agricultural reservoir provides positive effects in flood control and flood damage reduction.

• 생태와환경
• /
• 제54권3호
• /
• pp.221-228
• /
• 2021

Recently, environmental DNA (eDNA)-based metabarcoding approaches have been proposed to evaluate the status of freshwater ecosystems owing to various advantages, including fast and easy sampling and minimal habitat disruption from sampling. Therefore, as a case study, we applied eDNA metabarcoding techniques to evaluate the effects of an abandoned mine land located near a headwater stream of Nakdonggang River, South Korea, by examining benthic macroinvertebrate diversity and compared the results with those obtained using the traditional Surber-net sampling method. The number of genera was higher in Surber-net sampling (29) than in the eDNA analysis (20). The genus richness tended to decrease from headwater to downstream in eDNA analysis, whereas richness tended to decrease at sites with acid-sulfated sediment areas using Surber-net sampling. Through cluster analysis and non-metric multidimensional scaling, the sampling sites were differentiated into two parts: acid-sulfated and other sites using Surber-net sampling, whereas they were grouped into the two lowest downstream and other sites using eDNA sampling. To evaluate freshwater ecosystems using eDNA analysis in practical applications, it is necessary to constantly upgrade the methodologies and compare the data with field survey methods.