• Title/Summary/Keyword: Coastal control

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Studies on the Adatability of Introduced Species from Australia for Grassland Establishment on Saline Land(Part I) (간척지(干拓地) 초지조성(草地造成)을 위(爲)한 도입호주품종(導入濠洲品種)의 적응성(適應性) 조사(調査)에 관(關)한 연구(硏究) (제(第)1보(報)))

  • Kwon, S.K.;Lee, I.H.;Kim, Y.K.
    • Korean Journal of Agricultural Science
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    • v.3 no.1
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    • pp.67-75
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    • 1976
  • This experiment was studies for grassland establishment on west coastal saline land in Korea from May 1975 to March 1976 and used seeds were introduced from Australia. The results of adaptability were summarized as follow. 1. The seeds germination percentage was not influence in 0.5% salt included, but delayed days in 1% salt included and decreased germination percentage. 2. Any experimental grasses species were not growth on the 0.5% salt included soil and also growth was much damaged on the 0.05% salt included soil. It was suggested that $Mg^+$, $K^+$ ions involved with $Na^+$ ion. 3. The yield of grasses were much decreased on 0.05% salt included soil which compared control group. The yield rate of decrease were 30% in kikuyu, 60% in strawberry clover, 63% in reed canarry and 89% in orchard grass. 4. For winter-hardness test, nearly all the species well overwintered but except kikyu. 5. One of salt tolerance native grass (Agrostis distans crieseb var coreensis, Hackel) was discovered in saline area, and it was growth from middle of May to Middle of September. Also it was known that the native grass was good feed stuff but it was not so long in growth life. 6. It was concluded that more experimental work must be carried out to select of salt tolerance grass for grassland establishment on saline by introduce some more species such like saltgrass, saltbush, shadsclae from foreign land.

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Overview of Major Oil Spill at Sea and Details of Various Response Actions 2. Analysis of Marine Oil Pollution Incidents in Korea (대형 기름유출사고와 방제조치에 관한 연구 2. 국내 해양 기름오염사고 분석)

  • Kim, Kwang-Soo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.19 no.5
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    • pp.467-475
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    • 2013
  • In order to seize quantitative materials as part of studies on measures for oil pollution prevention and control, the statistics of oil pollution incidents in Korean coastal waters for 10 years from 2003 to 2012 were analyzed with relation to the number of oil spills and the volume of oil spilt according to causes, sources and sea areas of spills. Total number and total volume of oil spills for 10 years were found to be 2,833 cases and 17,877 kL, respectively. 50.4 %(1,429 cases) of total number of oil spills were caused by negligence, although oil spillage due to negligence was 294 kL(1.7 %). While oil spillage caused by marine accidents was 17,400 kL(97.3 %), marine accidents accounted for 27.9 %(790 cases) of total number of oil spills. While negligence had a great influence on the number of oil spills, marine accidents had a huge impact on the amount of oil spilt. Fishing boats accounted for 42.7 %(1,210 cases) of the number of oil spills, and although oil tankers accounted for 9.2 %(261 cases) of the number of oil spills, oil spillage from oil tankers was 15,488kL(86.7 %). It means that oil tankers such as VLCC or ULCC may be the main sources of major oil spills and a few very large spills are responsible for a high percentage of the amount of oil spilt. While the number of oil spill incidents was closely related to the accidents of fishing boats, the volume of oil spilt was greatly affected by the major oil spill incidents of oil tankers such as M/T Hebei Spirit. The number and volume of oil spills were shown to be 1,613 cases(56.9 %) and 3,804 kL(21.3 %) in South Sea, 700 cases(24.7 %) and 13,501 kL(75.5 %) in West Sea, and 520 cases(18.2 %) and 572 kL(3.2 %) in East Sea of Korea, respectively. The highest number of oil spills was found in South Sea and the most volume of oil spilt was shown in West Sea of Korea for 10 years.

Prelaunch Study of Validation for the Geostationary Ocean Color Imager (GOCI) (정지궤도 해색탑재체(GOCI) 자료 검정을 위한 사전연구)

  • Ryu, Joo-Hyung;Moon, Jeong-Eon;Son, Young-Baek;Cho, Seong-Ick;Min, Jee-Eun;Yang, Chan-Su;Ahn, Yu-Hwan;Shim, Jae-Seol
    • Korean Journal of Remote Sensing
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    • v.26 no.2
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    • pp.251-262
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    • 2010
  • In order to provide quantitative control of the standard products of Geostationary Ocean Color Imager (GOCI), on-board radiometric correction, atmospheric correction, and bio-optical algorithm are obtained continuously by comprehensive and consistent calibration and validation procedures. The calibration/validation for radiometric, atmospheric, and bio-optical data of GOCI uses temperature, salinity, ocean optics, fluorescence, and turbidity data sets from buoy and platform systems, and periodic oceanic environmental data. For calibration and validation of GOCI, we compared radiometric data between in-situ measurement and HyperSAS data installed in the Ieodo ocean research station, and between HyperSAS and SeaWiFS radiance. HyperSAS data were slightly different in in-situ radiance and irradiance, but they did not have spectral shift in absorption bands. Although all radiance bands measured between HyperSAS and SeaWiFS had an average 25% error, the 11% absolute error was relatively lower when atmospheric correction bands were omitted. This error is related to the SeaWiFS standard atmospheric correction process. We have to consider and improve this error rate for calibration and validation of GOCI. A reference target site around Dokdo Island was used for studying calibration and validation of GOCI. In-situ ocean- and bio-optical data were collected during August and October, 2009. Reflectance spectra around Dokdo Island showed optical characteristic of Case-1 Water. Absorption spectra of chlorophyll, suspended matter, and dissolved organic matter also showed their spectral characteristics. MODIS Aqua-derived chlorophyll-a concentration was well correlated with in-situ fluorometer value, which installed in Dokdo buoy. As we strive to solv the problems of radiometric, atmospheric, and bio-optical correction, it is important to be able to progress and improve the future quality of calibration and validation of GOCI.

Characteristics of Seepage Water and Groundwater in a Coastal LPG Storage Cavern of Jeonnam (전남 해안 LPG 저장공동 유출수와 주변 지하수의 수질특성)

  • Lee, Jin-Yong;Choi, Mi-Jung;Kim, Hyun-Jung;Cho, Byung-Wook
    • Journal of Soil and Groundwater Environment
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    • v.14 no.4
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    • pp.33-44
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    • 2009
  • Water curtain of an underground LPG storage cavern is a facility to prevent leakage of high pressure gases, for which groundwater should flow freely towards the cavern and groundwater level also must be stably maintained. In this study, in order to evaluate qualities of seepage water and surrounding groundwater of an underground LPG storage cavern in Yeosu, 4 rounds of samplings, field measurements and laboratory analyses (February, May, August, October of 2007) were conducted. According to field measurements, pH was weak acidic to neutral but it gradually increased with time. Electrical conductivity (EC) of groundwater near a salt stack showed very high values between 10.47 and 38.50 mS/cm. Dissolved oxygen (DO) showed a very wide range of 0.20~8.74 mg/L and a mean of oxidation-reduction potential (ORP) was 159 mV, which indicated an oxidized condition. Levels of $Fe^{2+}$ and $Mn^{2+}$ were mostly less than 3 mg/L. All of seepage waters showed a Na-Cl type while only groundwater near the salt stack showed a Na-Cl type with a high total dissolved solid. The other groundwaters exhibited typical $Ca-HCO_3$ types. Levels of aerobic bacteria were mostly very high (573-39,520 CFU/mL). Based on the analyses of these hydrochemistry and biological characteristics, it is concluded that there are no particular problems in groundwater and seepage water, which not causing a trouble in the cavern operation. However, both for control of bio-clogging and for sustainable operation of the water curtain system, a regular hydrochemical and microbiological monitoring is required for the seepage water and surrounding groundwater.

Endoparasitic Dinoflagellates, Amoebophrya spp. and their Host Dinoflagellates in Jinhae Bay, Korea (진해만에 출현하는 기생성 와편모류 Amoebophrya spp.와 숙주 와편모류)

  • Park, Jong-Gyu;Hur, Hyun-Jung;Coats, D. Wayne;Yih, Won-Ho;Ha, Na
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.12 no.4
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    • pp.359-369
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    • 2007
  • Amoebophrya is an obligate endoparasitic eukaryotic dinoflagellate infecting host species and eventually killing them within a short period. Because of its host specificity and significant impacts on population dynamics of host species, it has long been proposed to be a potential biological agent for controlling harmful algal bloom (HAB). For several decades, the difficulties of culturing host - parasite systems have been a great obstacle to further research on the biology of Amoebophrya but recent success of several culture systems reactivates this research field. In this study, as a preliminary work for understanding the impacts of Amoebophrya on the population dynamics of host species, semimonthly occurrence of infected host dinoflagellates by Amoebophrya spp. had been observed in Jinhae Bay for two years and with a host - parasite system cultivated, host specificity of Amoebophrya spp. on several dinoflagellates was tested. Amoebophrya spp. were observed in the cellular organelle and cytoplasm of several species including Akashiwo sanguinea, Ceratium fusus, Dinophysis acuminata, Heterocapsa triquetra, Oblea sp., Prorocentrum minimum, P. triestinum, Scrippsiella spinifera, and S. trochoidea. Among them two host - parasite systems for an athecate dinoflagellate, A. sanguinea, and for a thecate dinoflagellate, H. triquetra, had been able to be successfully established as laboratary cultures. Cross-infection tests for 6 species of dinoflagellates in which Amoebophrya was observed or had been reported to exist confirmed high preference for host species of the parasite. Through the continuous research on Amoebophrya occurring in Korean coastal waters, we need to maintain various host - parasite culture systems, which will be very helpful for understanding its ecological role in marine food webs and for applying the species to biologically control harmful algal blooms.

Taxonomical Classification and Genesis of Jeju Series in Jeju Island (제주도 토양인 제주통의 분류 및 생성)

  • Song, Kwan-Cheol;Hyun, Byung-Geun;Moon, Kyung-Hwan;Jeon, Seung-Jong;Lim, Han-Cheol;Lee, Shin-Chan
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.2
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    • pp.230-236
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    • 2010
  • Jeju Island is a volanic island which is located about 96 km south of Korean Peninsula. Volcanic ejecta, and volcaniclastic materials are widespread as soil parent materials throughout the island. Soils on the island have the characteristics of typical volcanic ash soils. This study was conducted to reclassify Jeju series based on the second edition of Soil Taxonomy and to discuss the formation of Jeju series in Jeju Island. Morphological properties of typifying pedon of Jeju series were investigated, and physico-chemical properties were analyzed according to Soil survey laboratory methods manual. The typifying pedon has dark brown (10YR 3/3) silt clay loam A horizon (0~22 cm), strong brown (7.5YR 4/6) silty clay BAt horizon (22~43 cm), brown (7.5YR 4/4) silty clay Bt1 horizon (43~80 cm), brown (7.5YR 4/6) silty clay loamBt2 horizon (80~105 cm), and brown (10YR 5/4) silty clay loam Bt3 horizon (105~150 cm). It is developed in elevated lava plain, and are derived from basalt, and pyroclastic materials. The typifying pedon contains 1.3~2.1% oxalate extractable (Al + 1/2 Fe), less than 85%phosphate retention, and higher bulk density than 0.90 Mg $m^{-3}$. That can not be classified as Andisol. But it has an argillic horizon from a depth of 22 to 150 cm, and a base saturation (sum of cations) of less than 35% at 125 cm below the upper boundary of the argillic horizon. That can be classified as Ultisol, not as Andisol. Its has 0.9% or more organic carbon in the upper 15 cm of the argillic horizon, and can be classified as Humult. It dose not have fragipan, kandic horizon, sombric horizon, plinthite, etc. in the given depths, and key out as Haplohumult. A hoizon (0~22 cm) has a fine-earth fraction with both a bulk density of 1.0 Mg $cm^{-3}$ or less, and Al plus 1/2 Fe percentages (by ammonium oxalate) totaling more than 1.0. Thus, it keys out as Andic Haplohumult. It has 35% or more clay at the particle-size control section, and has thermic soil temperature regime. Jeju series can be classified as fine, mixed, themic family of Andic Haplohumults, not as ashy, thermic family of Typic Hapludands. In the western, and northern coastal areas which have a relatively dry climate in Jeju Island, non Andisols are widely distributed. Mean annual precipitation increase 110 mm, and mean annual temperature decrease $0.8^{\circ}C$ with increasing elevation of 100m. In the western, and northern mid-mountaineous areas Andisols, and non Andisols are distributed simultaneously. Jeju series distributed mainly in the western and northern mid-mountaineous areas are developed as Ultisols with Andic subgroup.

A Study on Direct Sowing Culture of Scutellaria baicalensis GEORGE Cultivated after Barley (황금의 맥후작 직파 재배 연구)

  • 권병선;신종섭
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2001.11b
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    • pp.49-61
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    • 2001
  • This study was carried out to determine the effect of various fertilizer levels, sowing time and planting density on the growth and yield of Scuteliaria baicalensis GEORGE cultivated after the barley in the southern coastal areas of Korea under the non- mulching condition by direct sowing culture. The flowering date of medium dressing plot(N : P$_2$O$\sub$5/ : K$_2$O=9 : 13.5 : 9kg/10a) and heavy dression plot(N : P$_2$O$\sub$5/, : K$_2$O=12 :18 : 12kg/10a) were July 23. The flowering date of the medium and the heavy dressing plot was delayed by 3days compared with that of non-fertilizing plot. The growth characteristics such as stem length, diameter of main stem, number of branch per plant, main root length, main root length, main root thickness and dry weight of stem leaves were more increased at medium dressing plot than that of other fertilizer levels, The root dry weight of in Scutellaria baicalensis GEORGE cultivated after barley was hlghest at the fertilizing plot of N : P$_2$O$\sub$5/ : K$_2$O=9 : 13.5 : 9kg/10a. The dried-root yield was 178kg in medium dressing plot, 167kg in standard dressing pot, and 126kg in non-dressing plot, The dried-root yield of medium dressing plot was 7% and 41 cie higher than that of standard dressing pot and non-dressing control plot, respectively. Emergence and flowering dates in the sowing time of June 1 were earlier than those of the other sowing times. In the sowing time of June 1, length and diameter of main stem, number of node per main stem, number of branch per plant and dry weight of stem leaves were greater than those of sowing times of June 10 and June 20. Yield components such as main stem length and diameter, main stem numbers, branches per plant, dry weight of stem leaves, main root length and thickness, number of large root and fine root per plant, and dry weight of root were the highest at the sewing time of June 1 as the yield of 71.3kg/10a. Optimum sowing time of Scuteilaria baicaiensis GEORGE cultivated after barley was June 1 in southern areas of Korea. Stem length was long in dense planting of 20${\times}$10cm and short in spacious planting of 30${\times}$10cm and 40${\times}$10cm by direct sowing cultivated after barley. Stem diameter was thick in spacious planting of 30${\times}$10cm and 40${\times}$10cm and was thin in dense planting of 20${\times}$10cm by direct sowing cultivated after barley. Length and dry weight of root per plant were decreased in dense planting of 20${\times}$10cm and were increased in spacious planting of 30${\times}$10cm and 40${\times}$10cm by direct sowing cultivated after barley. Yield of dry root was highest in optimum planting density(30${\times}$10cm 33 plants/㎡) by direct sowing cultivated after barley. The correlation coefficient between number of planting plant and stem length showed highly positive correlation. These characters of stem diameter, number of branches, main root length and yield of dry root mentioned above showed negative correlations with planting plants.

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A Study on Transition of Rice Culture Practices During Chosun Dynasty Through Old References IX. Intergrated Discussion on Rice (주요(主要) 고농서(古農書)를 통(通)한 조선시대(朝鮮時代)의 도작기술(稻作技術) 전개(展開) 과정(過程) 연구(硏究) - IX. 도작기술(稻作技術)에 대(對)한 종합고찰(綜合考察))

  • Guh, J.O.;Lee, S.K.;Lee, E.W.;Lee, H.S.
    • Korean Journal of Weed Science
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    • v.12 no.1
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    • pp.70-79
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    • 1992
  • From the beginning of the chosun dynasty, an agriculture-first policy was imposed by being written farming books, for instance, Nongsajiksul, matched with real conditions of local agriculture, which provided the grounds of new, intensive farming technologies. This farming book was the collection of good fanning technologies that were experienced in rural farm areas at that time. According to Nongsajiksul, rice culture systems were divided into "Musarmi"(Water-Seeded rice), /"Kunsarmi"(dry-seeded rice), /transplanted rice and mountainous rice (upland rice) culture. The characteristics of these rice cultures with high technologies were based of scientific weeding methods, improved fertilization, and cultivation works using cattle power and manpower tools systematically. Reclamation of coastal swampy and barren land was possible in virtue of fire cultivation farming(火耕) and a weeding tool called "Yoonmok"(輪木). Also, there was an improved hoe to do weeding works as well as thinning and heaping-up of soil at seeding stages of rice. Direct-seeded rice culture in flat paddy fields were expanded by constructing the irrigation reservoirs and ponds, and the valley paddy fields was reclaimed by constructing "Boh(洑)". These were possible due to weed control by irrigation waters, keeping soil fertility by inorganic fertilization during irrigation, and increased productivity of rice fields by supplying good physiological conditions for rice. Also, labor-saving culture of rice was feasible by transplanting but in national-wide, rice should not basically be transplanted because of the restriction of water use. Thus, direct-seeded rice in dry soils was established, in which rice was direct-seeded and grown in dry soils by seedling stages and was grown in flooded fields when rained, as in the book "Nongsajiksul". During the middle of the dynasty(AD 1495-1725), the excellent labor-saving farmings include check-rowing transplanting because of weeding efficiency and availability in rice("Hanjongrok"), and, nurserybed techniques (early transplanting of rice) were emphasized on the basis of rice transplanting ["Nongajibsung"]. The techniques for deep plowing with cattle powers and for putting more fertilizers were to improve the productivity of labor and land, The matters advanced in "Sanlimkyungje" more than in "Nongajibsung" were, development of "drybed of rice nursery stock", like "upland rice nursery" today, transplanting, establishment of "winter barly on drained paddy field, and improvement of labor and land-productivity in rice". This resulted in the community of large-scale farming by changing the pattern of small-farming into the production system of rice management. Woo-hayoung(1741-1812) in his book "Chonilrok" tried to reform from large-scale farmings into intensive farmings, of which as eminent view was to divide the land use into transplanting (paddy) and groove-seeding methods(dry field). Especially as insisted by Seo-yugo ("Sanlimkyungjeji"), the advantages of transplanting were curtailment of weeding labors, good growth of rice because of soil fertility of both nurserybed and paddy field, and newly active growth because rice plants were pulled out and replanted. Of course, there were reestimation of transplanting, limitation of two croppings a year, restriction of "paddy-upland alternation", and a ban for large-scale farming. At that period, Lee-jiyum had written on rice farming technologies in dry upland with consider of the land, water physiology of rice, and convenience for weeding, and it was a creative cropping system to secure the farm income most safely. As a integrated considerations, the followings must be introduced to practice the improved farming methods ; namely, improvement of farming tools, putting more fertilizers, introduction of cultural technologies more rational and efficient, management of labor power, improvement of cropping system to enhance use of irrigation water and land, introduction of new crops and new varieties.

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