• Title/Summary/Keyword: 1982년6월

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Studies on the Water Quality along the Midstream of Nakdong River in $1978{\sim}80$ (낙동강(洛東江) 중류수계(中流水系)의 수질조사(水質調査) 연구(硏究)$(1978{\sim}80$년(年)))

  • Choi, Eon-Ho;Lee, Su-Rae
    • Korean Journal of Environmental Agriculture
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    • v.1 no.1
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    • pp.31-38
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    • 1982
  • The water quality at the Nakdong River stream was surveyed for 3 years from 1978 to 1980 at quarterly intervals of January, April, June and October at 12 sites along the main stream from Sangju to Imhaejin and at 2 sites of Geumho and Nam River tributaries. The overall results are summarized as follows: 1) The levels of dissolved oxygen in the Geumho River tributary on the basis of three-year average were 0.7 ppm in January, 1.3 ppm in April, 4.0 ppm in July and 0.8 ppm in October. BOD concentrations in the same period were 91 ppm in January, 37 ppm in April, 6 ppm in July and 24 ppm in October. The water of Geumho River was so highly contaminated that the water seems to be unsuitable for any type of water use. 2) The relatively clean water in the upstream of the main Nakdong River was rapidly polluted by the highly contaminated water of Geumho tributary. That is, dissolved oxygen and BOD at Hwawon site right after junction of the tributary were 10.4, 8.8 ppm in January, 5.8, 6.5 ppm in April, 6.3, 3.2 ppm in July and 7.0, 5.3 ppm in October, respectively. The values of turbidity, ammoniacal nitrogen and electrical conductivity were also observed to be quite high.

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Malaysia국 Ambong만에 이식한 참굴 Crassostrea gigas의 성장 (The Growth of Pacific Oyster Crassostrea gigas Transplanted into Ambong Bay in Malaysia)

  • Yoo Sung Kyoo;Ryu Ho Young
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.15 no.1
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    • pp.42-46
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    • 1982
  • Followings are the results of growth of Pacific oysters transplanted from the temperate waters of Korea in February 1981, and cultivated upto early July in the tropical waters of Ambong Bay in Malaysia: The shell length increased from 5.78 mm in February to 25.01 mm in July, and the shell height increased from 7.33 mm in february to 38.91mm in July. The meat weight progressively increased and reached the maximum value of 1.66g in May, but then gradually decreased until July, and the fatness varied from $28\%$ of maximum in March to $11\%$ of minimum in July-Survival rate was $47\%\;and\;39\%$ of the initial number in June and July respectively.

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A study on the change and cause of the channel in the midstream of singwang river and naeng river in pohang - Comparing the changes before and after typhoon hinnamnor with the past - (포항 신광천과 냉천 중류의 하도 변화와 그 원인에 대한 분석 - 과거 및 태풍 힌남노 전후 비교를 중심으로 -)

  • Seonggi An;Chanjoo Lee;Woo-Chul Kang;Jongmin Kim;Gyeonghyeon Min;Byungsun Yoo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.61-61
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    • 2023
  • 우리나라는 여름철 집중호우 시 발생하는 홍수로 인해 중소하천의 확폭(Widening) 및 하안침식이 자주 발생하고 있으나, 이에 대해 홍수 피해 관점으로만 분석되고 있으며 체계적인 수리학적, 지형학적 분석은 미흡한 실정이다. 본 연구에서는 먼저, 1982-2022년의 지도 및 항공사진, 정사영상 등을 분석하여 포항시 신광천과 냉천 중류의 하도 변화를 살펴보고, 2022년 9월 태풍 힌남노의 내습 시 발생한 홍수로 인해 초래된 하도 변화를 분석하였다. 신광천 항사리 지점의 경우, 하천 우안에 제방이 축조되지 않았던 1982년에는 하폭이 상대적으로 넓었으나, 1992년 제방 축조 이후 우안 충적지가 하도에서 분리되며 하폭이 감소하였다. 2011년의 하도는 대부분의 면적이 식생으로 덮여 하천의 흐름이 잘 관찰되지 않으나, 2021년에 식생 제거로 하도가 식별되지만 하폭은 과거에 비해 더욱 감소하였다. 태풍 힌남노 내습 시 포항시의 6시간 누적 강우량은 315.3 mm 로 100년 빈도를 초과하는 집중호우가 발생하였으며, 그 결과 확폭이 발생하였다. 단면에서 보면 좌안 활주사면은 5 m 가량의 퇴적고를 보였고, 우안 공격사면은 평균 23.3 m 측방으로 침식되었다. 그 결과 1982년 하폭과 유사한 수준으로 확대되었다. 문덕리 지점(공장지대)과 냉천 용산리(아파트)의 경우에도 각각 평균 14 m, 18 m 의 하안침식을 보였다. 이러한 결과는 지난 30여 년 전 축조된 기존 제방이 유실되면서 발생한 것으로 홍수로 인해 과거의 하폭으로 복귀할 수 있음을 의미한다. 2022년 홍수에 의한 하도 변화와 같은 지형학적 변화를 고려할 때, 보다 안정적인 하천관리를 위해서는 하천 설계 시 과거 지도상의 하도 범위 및 기왕홍수로 인한 하안선 변동을 고려하는 것이 필요하다.

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The Effect of the Pea Carb (Pinnotheres pholadis) on the Reproductive Capacity of the Blue Mussel (Mytilus edulis galloprovincialis) (섶 속살이게, Pinnotheres pholadis의 기생이 진주담치의 번식력에 미치는 영향)

  • YOO Myong Suk;KAJIHARA Takeshi
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.18 no.6
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    • pp.581-585
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    • 1985
  • This study was carried out with blue mussels at Otsuchi Bay in Japan from August 1981 to May 1982, in order to investigate the effect of the parasitic pea crab (Pinnotheres pholadis) on the reproductive capacity of host blue mussels (Mytilus edulis galloprovincialis). The results show that pea crabs delay gonad development of host mussels about one month and lower their fatness rate by intercepting nutrients. The parasitization with pea crabs is thought not to prevent spawning activity itself, but to reduce the number of germ cell resulting in the reduced space of gonads.

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Culture of the Ark Shell, Anadara broughtonii in Yoja Bay (여자만에서의 피조개 양성)

  • KWON Woo-Seop;CHO Chang-Hwan
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.19 no.4
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    • pp.375-379
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    • 1986
  • A culture experiment of the ark shell, Anadara broughtonii, one of the edible clams, was carried out in Yoja Bay located at the south ern coast of Korea to find the state of growth and any problems which influence them. Seed shells at an average length of 2.5cm and a weight of 2.5g were planted on bottom mud with a density 20 to 40 shells per square meter on March 10 and 11, 1982. Shell length, shell height, shell breadth, meat weight (wet weight), and total weight for six months from August 1982 to February 1983 were measured to find their state of growth. At the same time, the survival rate was investigated during the whole culture period through December 1983 when they were harvested. Growth, on the whole, was fast when water temperature was high. For a year, an average shell length and total weight attained to 6.1 cm and 63.0g respectively and meat weight was gained to 19.5g. It showed that the state of growth was favourable. Shell shape became round from the oval ana meat weight increase was faster than shell growth as time goes by regardless of water temperature while both shells and total weight increased faster during high temperature. A month after seed shells were planted, about $30\%$ of them was dead and a high mortality, say $5\%\;to\;8\%$ per month, was kept till September. It dropped to around $2\%$ aften divers eliminated starfish, Asterias spp., in August. Thereafter, the rate maintained through December. In all, the final survival rate was about $10\%$ at the time of harvest in December 1983. It was caused mainly by starfish predation. Therefore, a best way for satisifactory culture is seemed to find a way to get rid of the starfish.

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Coastal Algal Blooms Caused by the Cyst-Forming Dinoflagellates (휴안포자(Cyst)를 형성하는 과편모조류에 의한 적조발생)

  • KIM Hak-Gyoon;PARK Joo-Suck;LEE Sam-Geun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.23 no.6
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    • pp.468-474
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    • 1990
  • Eight species, 6 Dinophyceae and 2 Raphidophyceae, caused a bloom in the southeastern coastal waters mainly in Chinhae Bay in Korea from March to September since 1982. Scrippsiella trochoidea and Heterocapsa triquetra bloomed in March then ensued a vernal species Heterosigma akashiwo. And Cochlodinium sp. and Alexandrium affine were occurred as causative organism in fall next to the estival dinoflagellates Gyrodinium instriatum and Pheopolykrikos hartmannii. Among them, spatio-temporal similarity of outbreak was significant in Heterosigma akashiwo since 1983, and a bit apparent for Cochlodinium sp.. The density was in the level from $10^3\;to\;10^5\;cells/ml$ and was dependent on the cell size rather than environmental characteristics.

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Analysis of the 2015 drought for Geum river basin and northwesten area in Chungnam (2015년 금강수계 및 충남 서북부 지역의 가뭄상황 분석)

  • Kim, Jeong Yup;Sung, Jang Hyun;Choi, Yong Joon;Park, Sang Geun;Kim, Yang Su
    • Proceedings of the Korea Water Resources Association Conference
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    • 2016.05a
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    • pp.245-245
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    • 2016
  • 지난 해 금강수계 강수량은 835.0mm로 평년('81~'10)의 64.3%, 삽교천수계는 765.1mm로 평년의 61.1% 정도로 매우 적었다. 특히 작년 6월부터 9월까지의 금강수계 강수량은 343.1mm로 평년 894.8mm의 38.3%, 삽교천수계 강수량은 301.1mm로 평년 860.6mm의 35.0% 수준으로 일반적으로 연간 강수량의 2/3가 여름철에 집중되는 현상과는 매우 다른 양상을 보이며 충남 서북부지역 8개 시 군은 최악의 가뭄을 겪었다. 따라서 작년 가을에는 전국적으로 가뭄이 만연한 가운데에서도 충남 서북부 8개 시 군에는 8월말부터 시작된 물 절약 캠페인에 이어서 10월8일부터 물 사용량 20%를 줄이기 위한 급수조정이 시작돼 지역주민들의 일상생활이 제약을 받기 시작하였다. 수도꼭지를 틀어보아도 시원한 물줄기를 볼 수 있은 지가 오래되었고 목욕이나 세차 등으로 충분히 물 쓰는 것이 눈치가 보일뿐더러 마실 물 걱정까지 해야 하는 상황이었다. 그리고, 금강수계 대부분의 생활용수 및 공업용수 공급을 담당하는 대청댐의 상황도 2015년 9월말 기준 누적 강수량은 536.7mm로 전년 강수량 791.6mm 대비 67.8%, 예년 강수량 1,077.5mm의 대비 49.8% 수준으로 강수량이 매우 적은 상황이었다. 9월말 기준으로 대청댐의 '15년 누적 강수량은 1981년 댐 운영 이후 가장 최소이며, 2순위로 9월말 누적 강수량이 적었던 해는 1994년이며 이 때 누적 강수량은 543.8mm, 3순위로 적었던 해는 1982년으로 이 해는 585.8mm였다. 대청댐의 저수위 현황을 살펴보면 6월말에 예년 수준과 비슷한 수위로 운영하였지만 7월말부터 예년보다 수위가 낮아지기 시작하여 8월 이후에는 예년과 격차가 나기 시작하였고 작년 10월 중순에는 1981년 댐 운영 이후 3번째로 낮은 저수율을 보이고 있는 상황이었다. 따라서, 이러한 상황에 대처하기 위해 6월부터 실수요량 수준으로 용수를 공급하기 시작하였고 8월말부터 농업용수 공급량 중 일부를 감량하였고 10월부터는 생공용수만 하루 1,987,200톤으로 계획하여 공급하면서 '16년 우기 전까지 최대한 저수량을 확보하면서 용수공급을 지속할 수 있도록 운영하였다. 본 연구에서는 '15년 강수량 부족으로 상당한 어려움을 겪은 충남지역을 중심으로 가뭄 현황을 분석하고, 충남 서북부지역의 주요 공급원인 보령댐과 기타 충남지역의 주수원인 대청댐의 운영현황과 가뭄상황을 타개하기 위해 추진한 방안 등을 살펴보고자 한다.

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Estimation for Daily Mean 10cm Soil Temperature (토양온도(土壤溫度)의 변화예측(變化豫測))

  • Park, Chang-Seo;Jung, Sug-Jae;Hyeon, Geun-Soo
    • Korean Journal of Soil Science and Fertilizer
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    • v.26 no.4
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    • pp.289-293
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    • 1993
  • To comply with the increasing demand from the agricultural industry for more accurate short-range weather information, statistical method for forecasting soil temperature was presented. Regression equation was derived to predict daily mean 10cm soil temperature for any day the year. The equation was based upon 10-daily mean 10cm soil temperature(10DM 10ST) for 6 years(1982~1987) at grass in Suweon. The possibility of estimating daily mean 10cm soil temperature was examined.

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A Study on the Classification of the Korean Anthozoa: 7. Scleractinia (Hexacorallia)

  • Song, Jun-Im
    • The Korean Journal of Zoology
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    • v.25 no.3
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    • pp.131-148
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    • 1982
  • A systematic study of Korean stony corals was done with specimens from 16 localities in the coastal seas of Korea for the period of 1969 through 1981. The scleractinians identified in the present study turned out to be 17 species, 11 genera, six families and five suborders. They were all new to the Korean scleractinians founa: Psammocora profundacella, Alveopora japonica, Culicia japonica, Caryophyllia japonica, Cyathoceras niinoi, Heterocyathus aequicostatus, H.japonicus, Stephanocyathus (Odontocyathus) spiniger, Desmophyllum insignis, flabellum distinctum, F. rubrum, F. transversale, Dendrophyllia boschmai, D. bribrosa, D. florulenta, Tubastraea aurea and T. coccinea.

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Occurrence of Major Diseases in Vegetable Growing under the Furnihsed Condition in Southern Part of Korea (남부 시설원예지대의 주요병 발생생태에 관한 연구)

  • Choi Jin-Sik;Park Chang-Seuk
    • Korean journal of applied entomology
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    • v.21 no.3 s.52
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    • pp.153-158
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    • 1982
  • The study was conducted to obtain the basic information on the diseases epidemics of vegetable crops grown in Namji, Jinju, Gimhae and Suncheon under the extremely varied and specified conditions, plastic film house. The disease survey was conducted from the end of April, 1951 to April 1982. Leaf mold and late blight were serious foliar disease in tomato during the seedling stage, especially when the infected seeds were sown. The diseases increased rapidly 35 days after seeding. In both continuous cultivation of cucumber and rotation with upland crops, incidence of Fusarium wilt was severe while incidence of the disease was negligible in cultivations after paddy rice or grafting on pumpkin. Downy mildew of cucumber was severe in Jinju and Suncheon area, however, it was not so serious in Namji area where the growing season of cucumber was unfavorable for the maximum disease incidence. Cucumber mosaic virus disease was prevalent in the areas surveyed and the disease incidence was increased rapidly after June. Powdery mildew prevailed at the early stage of cucumber growth after transplanting in Namji area. Root rot and wilting caused by Phytophthora capsici was as the most destructive disease in pepper grown under the vinyl house, especially in Namji and Jinju area where the pepper has been cultivated intensively. The Phytophthora attacked most parts of young plants during the winter time and then induced crown rot on the adults plants. Cultivation of pepper in vinyl house was almost impossible because of the Phytophora disease by the end of June. Virus diseases to tomato plants were prevalent throughout the surveyed area and the damage was also severe. In Jinju and Gimhae area leaf mold and late blight showed high infection rate in tomato during the harvest time.

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