평균조차(平均潮差)가 10cm내외(內外)인 포항(浦項) 영일만(迎日灣)으로 유입(流入)하는 형산강(兄山江)의 감조구간(感潮區間)을 채택(採擇)하여 유역내(流域內)의 부조(扶助) 수문기준점(水文基準點)에서 관측(觀測)한 자료(資料)와 하천유량(河川流量) 및 수질측정자료(水質測定資料) 등을 근거(根據)로 밀도유현상(密度流現象)을 분석(分析)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 영일만(迎日灣)의 조석현상(潮汐現象)은 1일(日)1회조(回潮)이며 대조차(大潮差) 0.104m, 소조차(小潮差) 0.066m, 평균조차(平均潮差) 0.085m로써 해면(海面)의 변동(變動)은 매우 작았다. 2. 감조구간내(感潮區間內)에는 해수(海水)의 영향(影響)으로 인(因)하여 약(約) 270만(萬) 이상(以上)의 물이 저류(貯溜)되고 있으며 이중에서 염분농도(鹽分濃度)가 이하(以下)로써 관개용수(灌漑用水)로 이용(利用) 가능한 수량(水量)은 약(約) 120 만(萬)톤에 달(澾)하고 있다. 3. 해수침투현상(海水浸透現象)은 간만(干滿)의 차(差)에 의한 수위변화(水位變化)는 작으나 만조시(滿潮時) 염분침입(鹽分侵入)이 탁월(卓越)하여 뚜렷한 층(層)이 형성(形成)되는 성층밀도류(成層密度流)가 되고 간조시(干潮時)에는 염수(鹽水)쐐기가 후퇴(後退)하면서 쐐기 상류단(上流端)의 염분(鹽分)이 담수(淡水)와 혼합확산(混合擴散)되면서 유하(流下)하여 잘 혼합(混合)된 하구(河口)를 형성(形成)한다. 4. 염수(鹽水)쐐기의 길이는 5.9km로 계산(計算)되었으나 실제로는 4.4km지점(地點)에 설치(設値)된 연일(延日) 잠수교(潛水橋)의 영향(影響)으로 인(因)하여 동지점(同地點)에서 로써 염수(鹽水)의 침투(浸透)가 중단(中斷)된다. 5. 담수(淡水)와 해수(海水)사이에 어떠한 크기의 밀도차(密度差)가 존재(存在)하는 한(限) 수로(水路)바닥을 따라 흐르는 순상류(純上流) 방향(方向)의 흐름이 존재(存在)한다.

Physical, chemical and biological surveys on Nakdong River estuary were made from October, 1985 to September, 1986. 1. For all the seasons except summer, the sea surface temperature in northwest area of the line which linked from Seo Island to Jisim Island was I-2˚C lower than in southeast area, but in summer the sea surface temperature in northwest area was I-2˚C higher than in southeast area. On the contrary, bottom temperature of coastal area was 1˚C higher than that of oceanic area except winter. 2. Surface salinity in summer and fall has minimum value of 1. 9%0 and maximum value of 32.9%0. This large variation was caused by the runoff of the Nakdong River. Effect of less saline Nakdong River water in northwest area of the line which linked from Seo Island to Jisim Island was greater than in southeast area. A strong current rip always formed near this line. 3. The yellowish-green colored zone was observed in the Nakdong River estuary throughout the year by influence of river discharge. The characteristics of the water quality in the zone have shown that the water color was grade 7 by the Forel water-color meter, transparency was less than 4 m, and concentration of suspended solids was more than 5 mg/1. This water body was in the state of eutrophication in terms of chlorophyll-a and inorganic nitrogen concentration during summer season. 4. During the study period, total 276 taxa were identified. Most of them were diatoms and dinoflagellates which consisted of 97.5%. The component ratio of the above two groups was 84.4% and 13.1 % respectively. Diatoms were plentiful in December and dinoflagellates in July. Dominant species were Nitzschia seriata in October, Thalassiosira rotula in December, Skeletoncma costatum in April, and Nitzschia longissima in July. 5. A total of 47 zooplankton taxa was identified from the samples collected. Copepods were numerically the most important components of zooplankton communities in the study area. The domir:ant copepod species were Paracalanus parvus, Acartia clausi and Temora turbinata. Noctiluca scintillans was the next important component. The other zooplankton with minor abundance were Cladocera. Sagitta spp., Cnidaria, Mysidacea, Lucifer spp. and Amphipoda. 6. During the study period, fishes from 47 families and 87 species were sampled in th~ study area. The four most abundant fish species were Rep~mucen//'s valencicnnei, Leiognathus n~cha!is, Amblychaeturicllthys hexanema and Sardirel/a zun:zsi. The fish species of the secondary importance in abundance were Cynoglossus joyneri, Sillago sihama, Engra~lis japonicus, Encdrias nebulos'l, Acanthogobius flavimanus, Trichiurus lepturus, LiParis tanai/ai, Cynagloss//'s interruptus, Aj)ogon line:z!us, Thrissz la 1l.'1la!ensis, and Limanda yokohamac.

낙동강하류(洛東江下流)의 순(純)갈대초지(草地)에 있어서 현존량(現存量)의 계절적(季節的) 변화(變化), 최대현존량(最大現存量)의 년별변화(年別變化), 물질생산구조(物質生産構造)의 계절변화(季節變化) 및 년순생산성(年純生産性)을 평가(評價)한 결과(結果)는 다음과 같다. 1. 순갈대초지(草地)의 최대현존량(最大現存量)은 9월(月) 중순(中旬)에 나타났으며 평균(平均) 최대일물질생산성(最大日物質生産成)은 6월(月)과 7월(月)사이로 32.7g/m2/d

Results investigated backwater phenomena at Geumho river basin to get a basic data for Daegu basin area development plan are as the follows. 1. It is a A=0.35 L 1.848 (r = 0.97), the relationship between basin area and river length at Geumho river. 2. Dividing the rainfall of Geumho river basin as two parts, a first half rainfall and a second half rainfall, the amount of a first half rainfall appeared 57.5% comparison with total rainfall. 3. The maximum flood discharge appeared 12 hrs. continuous rainfall rather than 24 hrs. continuous rainfall. 4. Results investigated backwater phenomena from Geumho II bridge to chungchun appeared the rising water level of 69 cm, 55 cm, 44 cm, at section III in the starting point water level of 1.8 m, 2.4 m, 4.0 m respectively. 5. Results investigated backwater phenomena by the flood water level appeared a similar form. There was a average rising water level of 30 cm at section III. At the results of this computation, it was confirmed that section III was affected the highest backwater phenomena among the observed river reaches in Geumho river. In addition, this paper should be given a assistance to decide a economic and safe section in construction of bank of river and estuary barrage.

물금, 양산천, 화명동 그리고 하단에 이르는 낙동강하류역에서 1983년 5~6월에 조석변동에 따른 수질분석과 유출량을 조사하여 오염부하량을 산출하고, 양산천의 본류에 대한 영향을 평가한 결과는 다음과 같다. 1. 양산천의 총부유물질 값은 6.1~21.3mg/l로 다른 측점에서보다 높았다. BOD의 평균치는 물금에서 1.16mg/l, 양산천 1.83mg/l, 화염동 0.79mg/l, 하단에서 3.56mg/l였다. 2. 영양염류의 농도는 하단에서 가장 높았고, 양산천에서의 값 역시 본류 보다 약간 높게 나타났다. 구리와 아연의 농도는 양산천에서 가장 높았다. 3. 각 측점에서의 평균유출량은 물금 97.02m super(3)/sec 양산천 3.7m super(3)/sec, 화명동에서 98.76m super(3)/sec였고 양산천의 본류에 대한 유출량 비는 약 4% 정도였다. 4. TSS, VSS, BOD에 대한 오염부하량들은 상류인 물금에서 하류인 화명동으로 갈수록 감소하였으나 BOD와 영양염류의 부하량은 화명동에서 높게 나타났다. 5. 물금에서의 평균부하량에 대한 양산천의 평균부하량 비는 약 8.3%로 나타났다.

1. 낙동강(洛東江) 하류(下流) 갈대군락(群落)에서 유기탄소(有機炭素)의 생성(生成), 분해(分解) 및 축적(蓄積)을 이론적(理論的) 분석(分析)에 의(衣)해서 평가하였다. 2. m2당(當) 낙엽(落葉)의 유기물(有機物), 유기탄소(有機炭素)의 함량(含量)은 각각(各各)이였으며 초지상(草地床)의 함량(含量)은 1154.96g과 669.93g 이었다. 3. 시별(尸別) 유기물(有機物), 유기탄소(有機炭素)의 함량(含量)은 광합성부(光合成部)에서는

This study focused to reveal mineralogical and petrochemical properties and the stratigraphy of the volcanic rocks along the downstream of the Hantan River in Choongaryong Rift Valley. The geological sequences of this area are as follows: The basement of this area consists of Precambrian metasedimentary rocks of the Yeoncheon System. The Biotite Granodiorite of Jurassic age intruded into the Yeoncheon System in the eastern side of the area. Several small exposures of the basalt of post-Jurassic age, which was maned as $quot;Tongjae Basalt$quot;occur dispersely along the west slope of the valley. A conglomerate formation overlay the eroded surface of Tongjae Basalt and contains rounded and angular pebbles and is unconformable overlain by Lapilli Lithic Tuff. A basalt outcrop exposed as small an exposure near Jangtanri creek and intruded the Lithic Tuff, maned as : Jangtanri Basalt.$quot; Granite porphyry dikes intruded into the Lithic Tuff in Tongjae area. An Alkali Loivine Basalt of the Cenozoic Era with 3∼11 different eruptions flowed on the surfaces of the abouve mentioned Precambian metasedimentary rocks, Biotite Granodiorite, Lithic Tuff and Unconsolidated in the valley and formed marrow plateaus. The Alkali Basalt consists mainly of olivine, diopside, hypersthene and labradorite, and is called in this study as $quot;Jeongog Basalt$quot;. the age of the last flow is estimated as late Pleistocene or early Holocene.

This study was conducted to understand the regional distribution characteristics of swans(Cygnus spp.) in downstream of t he Nakdong River , R.O.Korea from October 2008 to September 2013. During this period, a total of two species and 37,518 ind ividuals of Swans(Cygnus spp.) were observed, including 31,596 Whooper Swans(Cygnus cygnus) and 5,922 Tundra Swans (Cygnus columbianus), respectively. The average number of individuals observed in fifteen different areas was 2255.33 in Daemadeung(A), 143.50 in Jangja·Sinjado(B), 304.00 in Sajado·Doyodeung(C), 1928.00 in Lower Ulsukdo(D), 1392.67 in Ul sukdo(E), 50.17 in Ilwoongdo(F), 91.17 in Yeommak(G), 5.17 in Maekdogang(H), 0.00 in Pyeonggangcheon(I), 0.00 in Lowe r Noksan sluice(J), 2.83 in Upper Noksan sluice(K), 6.17 in Jomangang·Doonchido(L), 4.50 in Chideung(M), 0.83 in Joongs ado(N)and 66.17 in Daejeo sluice(O). The total average of these fifteen areas was 480.81. There was a significant differenc e among the survey areas (Kruskal-Wallis test,  =4055.68, P<0.001). In particular, the observed numbers were larger in Daemadeung, Lower Ulsukdo and Ulsukdo than in the other regions.

Cyanobacteria have been used as pollution indicator species in freshwater ecosystems, and identifying their fluctuations can be an important part about management of surface waters globally. Cyanotoxins produced by cyanobacteria are directly or indirectly a threat to human and environmental health. In order to confirm the potential risk of these cyanotoxins, the fluctuations of phytoplankton and phylogenetic analysis of cyanotoxin synthetase genes were conducted at each point in the Yeongsan River water system in Gwangju from November 2021 to October 2022. Diatoms which grow well in winter were dominant at 99.4 ~ 99.5%, and diatoms and green algae were dominant from the spring to autumn when the water temperature rises. Stephanodiscus spp. were dominant at 92.7 to 97.5 % at all sites in the winter, and Aulacoseira spp., which grow in warm water temperatures, were dominant in summer and autumn. Microcystis aeruginosa was dominant at 25.2% in summer only at site 5. mcyB and anaC have been detected as cyanotoxin synthetase genes. The phylogenetic tree of anaC could be divided into two groups (Group 1 & Group 2). Group 1 contained Aphanizomenon sp. and Cuspidothrix issatschenkoi. It is combined with Aphanizomenon sp. and Cuspidothrix issatschenkoi, which are known to produce cyanotoxins.

Heavy metal contaminations were investigated in fishes inhabiting the basins of Andong, Imha and Yeongju dam basins along the upper stream of the Nakdong river. The characteristics of heavy metals contamination in fish were investigated based on sampling sites located in the Andong dam basin. The muscle tissue was analyzed for 267 objects of 26 species from the Andong dam, 50 objects of 17 species from Imha dam, 38 objects of 9 species fromYoungju dam basin.The type and amount of heavy metals concentrated in the body of the fishes was found to be species-dependent. The heavy metal species which contamination increase through the Seokpo smelter are chromium, zinc, cadmium, and lead, and these are very likely the influence of the smelter. The concentration of eight heavy metals in fish from the Andong dam basin was higher than that in fish from the Imha and Youngju dam basins; the values for zinc, arsenic, and cadmium were significantly higher. However, mercury and lead exhibited high values in the Imha and Yeongju dam basins, respectively.

The coastal water is a space where salmon (Oncorhynchus keta), critical energy-conveying mediator, stay to adapt to different environments while traveling between ocean and river ecosystems for spawning and growth. The mid-eastern coast of Korea (MECW) is the southern limit of salmon distributed in the North Pacific Ocean. Understanding the distribution and migration characteristics of salmon in the MECW is important for the prediction of changes in the amount and distribution of salmon related to changes in the future marine environment. We analyzed the relationship between the salmon migratory timing ascending the Wangpi river and change in vertical seawater temperature and tidal elevation. Overall results highlight that (1) Salmon began to ascend the river when the sea surface water temperature (SST) decreased below 20°C; (2) The number of salmon ascending the river increased when the temperature difference between the upper and lower layers decreased, but decreased when the temperature difference was higher than 5°C; (3) The number of salmon ascending the river peaked, when the SST was 18°C-19°C and sea levels rose at high tide. This study provide important insight into predicting changes in the ecosystem energy circulation through climate change at its southern distribution limit.