• 생태와환경
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• 제35권2호통권98호
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• pp.141-144
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• 2002

The construction of river mouth dam has prevented seawater from backwarding to upstream in Kum river estuary since 1990. Field observation on environmental factors, and zooplankton and phytoplankton dynamics have been carried out three times with two month interval in the summer and autumn in 2000 at three selected stations in Kum river estuary. Blockade of seawater flowing backward to upstream caused sharp contrast of zooplankton fauna and phytoplankton flora between upstream and downstream of the river mouth dam. Freshwater cladocerans i.e., Bosmina longisrostris and Daphnia galeata dominated in the upstream, and marine copepods of Acartia omorii and Paracalanus crassirostris occurred abundantly in downstream of the dam. Freshwater diatoms did not distributed in the downstream of the dam except Melosira varians, while marine diatom of Cylidrotheca closterium occurred in benthic waters bath in upstream and downstream of the dam. The construction of the river mouth dam seems to play an ecological role to blockade the input of marine organism into the upstream in Kum river estuary.

• 한국지역지리학회지
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• 제20권2호
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• pp.176-188
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• 2014

일본의 댐 하구언 계획에 대한 전국적 차원의 반대운동은 1990년대 말 나가라강 하구언 반대운동을 계기로 본격화 되었다. 이는 중앙정부차원에서 댐 하구언 계획에 대한 재검토의 제도적 기반을 마련하도록 하는 기폭제가 되었다. 그 후 광역자치단체장들의 "탈 댐 하구언 선언" 참여와 민주당의 집권으로 수자원 및 하천 관리정책은 새로운 국면을 맞이하였다. 그러나 민주당 정권의 미숙한 대응책과 자민당의 재집권으로 댐 하구언 문제는 혼선을 거듭하고 있다. 이에 대한 근본적인 원인은 일본의 공공사업 정책결정 과정에 있어서의 재정에 대한 규범의 미 확립과 수리권 배분 제도의 경직성에서 찾을 수 있다. 향후 일본의 수자원 및 하천 정책이 성공적으로 정착되기 위해서는 최우선적으 로 공공사업 재정에 대한 구체적인 제도적 기반과 정부 조직 간의 실질적인 정책조정 시스템이 정비되어야 할 것이다. 이는 한국의 하천 및 물 관리 정책에 있어서도 시사하는 바가 크다.

• 생태와환경
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• 제34권3호통권95호
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• pp.251-258
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• 2001

낙동강 하구의 어류상과 하구둑에 설치한 어도의 어류 이동을 조사하기 위하여 2000년 6월부터 12월까지Dam을 중심으로 상${\cdot}$하류에 서식하는 어류와 어도를　통과하는 어종을 조사하였다. 하구에 Dam을 건설함으로서 기존에 존재하던 기수지역의 생태계가 완전히 사라지고 Dam을 중심으로 담수생태계와 해양생태계가 선상으로 인접하여 추이대가 형성되지 않았다. 조사기간에 해수와 담수의 두 생태계에서 채집된 어종은 모두 10목 29과 45속 49종이었는데 그 중 담수산 어류가 10종. 주연성 어류는 11종, 해산 어류는 28종이었다. 해수와 담수라는 생태계의 차이 때문에 조사지역별로　종 구성이 달랐는데, 명지지역에서 채집된 어류는 9목27과 36속 39종이며 우점종은 A. flavimanus (39.1%)이었고 담수영역인 사상지역은 6목 9과 19속 21종 중에　우점종은 A. macropterus (44.4%)였다. 낙동강 하구 Dam의 어도에 설치해 둔 video camera로 촬영한 어류를 3회에 걸쳐 확인한 결과 C. ectenes, C. carpio, H. labeo, S. gracilis majimae, P. altivelis, L. japonicus, A. japonica, M. cephalus 및 P. nebulosa 등 9종만이 확인되었다. 채집된 개체수를 기준으로 산출한소하성 어류의 이동율은 10.1%이었는데, 이를 근거로할 때 회유어류의 이동을 위해 어도의 설치는 필요하지만, 현재 운영되고 있는 어도의 효율성은 낮았다.

• 한국지형학회지
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• 제24권1호
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• pp.13-24
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• 2017

This study analyzes altitude changes of riverbed at 6 bridges in the upper and lower reaches of Yeongju Dam in Naeseong River, from 2009 to 2016 just before and after the dam construction. For 5 years from November 2010 to December 2015 when the dam was under construction, approximately 0.091m of the riverbed altitude in average more than twice before the dam construction was lowered, because of the effects of riverbed excavation for riverside maintenance in the upper reaches and transport limitation of flow and sediment by the dam in the lower reaches. Between November 2009 and December 2016 when the dam was in pre-construction and post-construction stages, respectively, the most sites in this study in the upper and lower reaches showed lowering in the riverbed altitudes. On the other hand, the riverbed around Hoeryongpo closed to the river mouth seems to be influenced by channel changes in Nakdong River rather than by the dam construction.

• 한국물환경학회지
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• 제28권4호
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• pp.512-522
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• 2012

This study is focused on fish fauna and distributional features along with physical gradients and stream orders in the Tamjin River basin, Korea. Fish sampling and investigation were conducted for 2 years from 2009 to 2010. Total number of fish species collected were 47 species of 16 family. The group of cyprinidae was mostly abundant. Both fish abundance and biotic index were declined with increasing altitude and longitudinal distance from the river mouth. Two species of Zacco temminckii and Pungtungia herzi were prevalent in most of sampling sites and showed no altitudinal and longitudinal differences. Most other species, however, were spatially restricted to specific regional altitudes. Several species including Zacco platypus, Squalidus gracilis majimae and P. herzi were broadly distributed from river mouth to 50 km. Eight species including Z. temminckii and Rhynchocypris oxycephalus only appeared in over 10 km from the river mouth. Both Odontobutis platycephala and Pseudobagrus koreanus were classified as "upstream dewelling species" observed only in over 30 km from the river mouth. High proportion of tolerant and omnivorous species were more dominated in the downstream zone of the dam, whereas intolerant and insectivorous species were abundant in the upstream zone of the dam. The variable of stream order showed positive relationship between number of fish species and total individuals collected. Sensitive species including insectivore had a declining tendency with increasing stream order, while tolerant specie including omnivore species had relatively increased with stream order. Overall, our study suggested that fish distribution considerably depends on altitudinal gradient and longitudinal distance from the river mouth as well as physical habitat.

• 한국환경과학회지
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• 제26권9호
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• pp.1031-1043
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• 2017

Recently severe drought caused the water shortage around the western parts of Chungcheongnamdo province, South Korea. A Diversion tunnel from the Geum river to the Boryong dam, which is the water supply dam for these areas has been proposed to solve this problem. This study examined hydraulic impacts on the Geum river associated with the diversion plan assuming the severe drought condition of 2015 would persist for the simulation period of 2016. The hydraulic simulation model was verified using hydrologic and hydraulic data including hourly discharges of the Geum river and its 8 tributaries, fluctuation of tidal level at the mouth of the river, withdrawals and return flows and operation records of the Geum river barrage since Feb. 1, 2015 through May 31, 2015. For the upstream boundary condition of the Geum river predicted inflow series using the nonlinear regression equation for 2015 discharge data was used. In order to estimate the effects of uncertainty in inflow prediction to the results total four inflow series consisting of upper limit flow, expected flow, lower limit flow and instream flow were used to examine hydraulic impacts of the diversion plan. The simulation showed that in cases of upper limit and expected flows there would be no problem in taking water from the Geum river mouth with a minimum water surface level of EL(+) 1.44 m. Meanwhile, the simulation also showed that in cases of lower limit flow and instream flow there would be some problems not only in taking water for water supply from the mouth of the Geum river but also operating the diversion facility itself with minimum water surface levels of EL(+) 0.94, 0.72, 0.43, and 0.14 m for the lower limit flow without/with diversion and the instream flow without/with diversion, respectively.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.519-519
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• 2023

Estuarine dams are a recent and global phenomenon. While estuarine dams can provide the benefit of improved freshwater resources, they can also alter estuarine processes. Due to the wide range of estuarine types and estuarine dam configurations, the effect of estuarine dams on estuaries is not well understood in general. To develop a systematic understanding of the effect of estuarine dam location and freshwater discharge interval on a range of estuarine types (strongly stratified, partially mixed, periodically stratified, and well-mixed), this study used a coupled hydrodynamic-sediment dynamic numerical model (COAWST) and compared flow, sediment transport, and morphological conditions in the pre- and post-dam estuaries. For each estuarine type, scenarios with dam locations at 20, 55 and 90 km from the mouth and discharge intervals of a discharge every 0.5, 3, and 7 days were investigated. The results were analyzed in terms of change in tide, river discharge, estuarine classification, and sediment flux mechanism. The estuarine dam location primarily affected the tide-dominated estuaries, and the resonance length was an important length scale affecting the tidal currents and Stokes return flow. When the location was less than the resonance length, the tidal currents and Stokes return flow were most reduced due to the loss of tidal prism, the dead-end channel, and the shift from mixed to standing tides. The discharge interval primarily affected the river-dominated estuaries, and the tidal cycle period was an important time scale. When the interval was greater than the tidal cycle period, notable seaward discharge pulses and freshwater fronts occurred. Dams located near the mouth with large discharge interval differed the most from their pre-dam condition based on the estuarine classification. Greater discharge intervals, associated with large discharge magnitudes, resulted in scour and seaward sediment flux in the river-dominated estuaries, and the dam located near the resonance length resulted in the greatest landward tidal pumping sediment flux and deposition in the tide-dominated estuaries.

• 한국물환경학회지
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• 제28권1호
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• pp.10-17
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• 2012

The middle and lower reaches of the Kum River system become stagnant in dry seasons with florishing of phytoplankton. In this study primary productivity of phytoplankton were measured by the C-14 uptake method and the P-I model method at seven main stream sites of the Kum River from the Daechung Dam outet to the river mouth. Nutrients (TN, TP, DIP, TIN) concentrations were measured in the mainstream and tributaries and compared with the variation of assimilation number. The range of primary productivity was $40{\sim}4,558mgC{\cdot}m^{-2}{\cdot}day^{-1}$ and it was higher than those of lentic ecosystems in Korea. Average TN and TP were $4.1mgN{\cdot}L^{-1}$, $70.6mgP{\cdot}m^{-3}$, respectively. Tributaries showed higher nutrient concentrations than the main stream. After two major tributaries merged with the discharging water of the Daechung Dam phyotplankton biomass and productivity increased drastically and remained at the similar eutrophic level through the downstream reach to the river mouth. Both dissolved phosphorus and nitrogen concentrations showed positive correlation with assimilation number of phytoplankton. In conclusion phytoplankton productivity is at the level of eutrophic water and it was higher than usual lentic habitats. Nutrient concentrations are critical factors in controlling productivity in the lower reach of the Kum River.

• 생태와환경
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• 제40권2호
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• pp.273-284
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• 2007

동물플랑크톤의 공간적 시간적 동태 변화에 대해서 섬진강 중하 류(하구언 댐 무)및 영산강 중 하류(하구언 댐 유)약 100 km구획 내에서 2004년 11월부터 2006년 8월까지 월 간격으로 조사하였다. 두 수계 내 동물플랑크톤 생체량의 공간적 변이는 뚜렷하였다. 영산강 조사 구획 내 총 동물플랑크톤 밀도의 종적 변이는 뚜렷하였다. 강 하류 지역의 하구언 댐으로 향할수록 총 동물플랑크톤 밀도가 증가하였다. 이에 반해 섬진강의 조사 구획 내 총 동물플랑크톤 밀도 변이는 통계적으로 유의하지 않았다. 영산강 구획 내 평균 총 동물플랑크톤 밀도는(평균범위: $199{\sim}817$ 개체수 $L^{-1}$), 3 조사지점, n=20) 섬진강 구획 내 평균 총 동물플랑크톤 밀도(평균범위: $4{\sim}60$개체수 $L^{-1}$, 4 조사지점, n=20)보다 약 $4{\sim}60$ 배 정도 높았다. 영산강 수계(총 동물플랑크톤 밀도의 86% 이상)에서 윤충류의 상대 풍부도는 섬진강 수계에 비해 현저히 높았다. 두 수역에서 우점 한 종은 Polyarthra spp., Brachionus spp., Colurella spp., 및 Keratella spp. 였다. 섬진강 구획 내에서의 요각류의 탄소 생체량은 강 하류로 향할수록 증가하였다(총 동물플랑크톤 탄소 생체량의 40% 이상). 식물플랑크톤에 대한 총 동물플랑크톤 섭식률의 평균 범위는 영산강 구획 내에서는 $21.2{\sim}92.6mL\;L^{-1}\;D^{-1}$이며, 섬진강 구획 내에서는 $2.1{\sim}2.6mL\;L^{-1}\;D^{-1}$의 변동 범위를 보였다. 동물플랑크톤의 섭식률을 고려 해 볼 때, 영산강 구획 내에서 동물플랑크톤에 의한 플랑크톤 먹이환내에서의 역할의 중요성이 섬진강 구획 내에서 보다 상대적으로 높을 것으로 사료된다.

• 생태와환경
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• 제50권4호
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• pp.422-431
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• 2017

본 연구에서는 상류댐과 열린하구를 가진 소유역에서 하천을 통해 기수역에 유출되는 육상기원 유기탄소의 농도와 발생기원의 시공간적인 분포를 파악하였다. 탐진강과 강진만의 연구결과, 탐진강 상류에 건설된 댐저수지와 강진만 해양에서는 여름 강우 이전에는 일차생산에 의해 저수지 기원, 그리고 해양기원 식물플랑크톤이 유기탄소의 성상과 조성에 영향을 미쳤다. 댐하류 하천에서는 상류댐에서 유래한 물질이, 그리고 금강천이 합류되면서 지류의 영향이 나타났다. 탐진강 하구역은 조석간만에 따라 탐진강에서 공급되는 물질과 바다에서 유입되는 물질, 그리고 국지적인 갈대습지의 영향이 복잡하게 작용하여 DOC와 POC의 농도변화에 영향을 주고 있었다. 특히, 탐진강에서는 대부분의 유기탄소가 DOC 형태로 강하구로 유출되는 반면, 강진만에서는 해양으로부터 들어오는 식물플랑크톤의 영향으로 POC 형태의 공급이 우세하게 나타나는 등 유기탄소의 성상별, 발생기원별 전이가 뚜렷하게 발생하였다. 이와 같은 강과 해양으로 연결하는 하천 유기탄소의 시공간적인 변화연구는 유역의 환경변화에 따른 생태계 물질이동 변화를 평가하고 예측하는 데 활용될 수 있을 것이다.