• Research in Plant Disease
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• v.22 no.3
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• pp.198-201
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• 2016

Recently, severe dieback of apple tree has occurred in the apple orchards of Chungbuk province. Dieback rate and its casual agents have been investigated on the Chungbuk province apple orchards in 2013-2015. Out of 29,265 apple trees in the 27 orchards throughout Chungbuk province, 4,000 apple trees (13.7%) showed dieback symptoms. The causes of dieback were Phytophthora rot (50.4%), violet root rot by Helicobasidium sp. (27.1%), rodents (10%), white root rot by Rosellinia sp. (6.3%), and freezing injury (6.3%). Compared to previous reports published in 1995 and 2006, Phytophthora rot was the most dominant disease, which is thought to be due to high temperature during growing season and the increase of lowland cultivation. Results of this study will be useful to establish of the management strategy of apple tree dieback that has been increased recently.

• Animal Systematics, Evolution and Diversity
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• v.11 no.4
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• pp.417-434
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• 1995

Three species (0. kinbergi, 0. sarsi and 0 . sarsi vadicola) of the genus Ophiura (Echinodermacta: Ophiuroidea) were sampled from the various localities of Korean waters (Kyonggi Bay in March and September, 1989 and February, 1994; Yellow Sea in September and October, 1992; Southern Sea and Korean Strait in May, 1992; and eastern coasts adjacent to Kangnung in April, July, October, 1993 and January, 1994). Results of the examination of 250 Operational Taxonomical Units (OTUs) are presented based on the 20 morphometric variables to evaluate their taxonomic characters and positions. In cluster analysis, 250 OTUs were divided into 3 phenons (0. kinbergi, 0 . sarsi and 0 . sarsi vadicola) at the Euclidean distance levels of 6.84 and 2 phenons (a phenon composed of 0 . sarsi and 0 . sarsi vadicola and the other of 0. kinbergi) at 7.50. Stepwise discriminant analysis was used in order to produce a good discrimination model and 13 morphological characters (the total number of comb papillae, the number of primary comb papillae and shape of comb papillae (2). etc.) were extracted. The results of canonical discriminant analysis illustrated clear distinction among 3 phenons by the distance of 8.26 between 0 . sarsi and 0. sarsi vadicola, 24.24 between 0 . kinbergi and 0. sarsi vadicola and 21.63 between 0 . kinbergi and 0 . sarsi.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.2
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• pp.86-94
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• 2000

In order to extract the spatio-temporal characteristics of long-term variability of the net heat flux on the sea surface in the East Asian marginal seas, empirical orthogonal function (EOF) analysis was conducted using data set calculated every 12 hours interval during 1978-1995. Among the first three modes explaining 73% of the total variance, the first mode having high peak at 1 year period indicates high variability area around the Sandong Peninsula and central and northeastern part of the East Sea. In the second mode which has spatial distribution of dipole type at the north and south, the peaks appear at 3.6 year and 2.3 year cycles. Time coefficient of the second EOF is believed to have close relation with the E1 Nino and has out-of-phase variation with NINO3 SST. Lagged correlation between NINO3 SST and time coefficient of the second EOF indicates four month time delay in the NINO3 SST. In the third mode which has opposite sign at the east and west, the periodicity of 6-9 year cycle has relatively clear appearance compared to other two EOFs. Also, high heat loss exceeding 800 W/$m^{2}$ in winter time occured at the south part of the Sandong Peninsula and Vladivostok. It reveals more frequent occurrence of about two times at the Sandong Peninsula than Vladivostok. The event is concentrated in January at Vladivostok, but it occurs primarily in December and January at the Sandong Peninsula.

• Proceedings of the Korea Water Resources Association Conference
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• 1990.07a
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• pp.221-221
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• 1990

진하 해수욕장은 부산에서 약 40km 정도 동해안도로를 거슬러 올라가면 경남 울주군 진하리에 위치한 조그마한 자연해변의 해수욕장이다. 해수욕장의 동쪽에서는 회야천이 흘러 들어오고, 이 하천의 3km 상류지점에는 댐을 축조하여 온산공단 및 주변지역의 생활용수를 공급하고 있다. 어울려서, 쾌적한 위락시설 단지로서는 최적이라고 생각된다. 현재 이 해안은 매년 침식이 진행되면서 해수욕을 할 수 있는 해변 공간이 줄어들고 있는 실정이다. 따라서 이 해안을 보전하기 위해서 관청과 주민들은 많은 심혈을 기울이고 있는 실정이다. 본 연구의 조사단은 1987년부터 해마다 수침측량을 실시하여 해수욕장의 지형변화를 조사하고 있다. 특히 이 해수욕장의 사빈은 몇년전 부터, 침식형의 사빈으로 변화되어 매년 많은 모래가 유실되는 현상이 발생하고 있어, 관청 및 주민들의 관심을 집중시키고 있다. 따라서, 금년에도 울주군청에서는 회야강 하구에 생성된 사주를 준설하여 준설된 모래를 해수욕장에 인공적으로 투입하여 양빈을 실시하고 있는 실정이다. 이 작업은 하구폐색의 문제를 해결할 뿐만 아니라 선박의 운행에도 큰 도움을 주고 있다. 이러한 작업은 기초해안 자료를 충분히 검토된 상태에서 실시되어야 한다. 그러치 못할 경우는 인위적으로 투입된 모래는 파랑에 의해서 다시 심해방향이나, 해안류를 따라서 다시 하구로 밀려오는 현상이 일어 날 것이다. 본 연구는 회야강 하구의 지형변화와 진하 해수욕장의 사빈의 변화를 정확히 파악하고져 단기간 동안 심천 측량을 실시한 결과를 이용하여 기존이론으로 해석한 결과를 제시함을 목적으로 한다.고 동시에 광 스트레스에 대한 저해를 감소시키는 것으로 보인다. 있다. 청주권의 무심천도 계획상은 대청댐의 물을 공급 받을수도 있도록 되어 있으나 현실상으로 상수도 원수로서의 공급마저도 매년 심한 원수 수질 문제(5-6월, 10월경의 취수장 부근의 부영양화 현상으로 인한 악취와 물 맛의 문제)를 1984년부터 겪고 있다. 이와 같이 도시권 하천의 수자원은 자연적, 인위적, 경제적, 법적, 제도적 여러 제한 요소로서 특성을 가지고 있으며 이는 날로 심해 가고 있는 실정이다. 그러므로 최적 물관리 시스템의 개발이 새로이 시작하는 수자원 개발 사업에서는 계획 단계에서부터 절실히 요구되는 바이며 기존 시설물의 관리 운영은 과감히 그 운영 관리 기준을 보완 재 정비하여야 할 것이다. 지금까지 대부분의 수자원 종합 개발 계획이 홍수방이나 용수 공급 및 수력 개발 등에 주력하여 왔으나 이제는 보다 더 수자원의 환경 보전적 차원과 도시의 안정적 발달을 위한 지역 및 권역 계획과 연계지워져서 양적인 안정 공급과 더불어 질적인 향상과 연계지워서 경제-사회적 요구에 부응할 수 있도록 도시권의 수자원을 최적 관리할 수 있는 방안을 강구하여야 할 것이다. 이는 각 도시 하천의 수자원의 정량적·정성적인 특성 및 제한 요소를 충분히 감안하여 수요-공급 개념에 의하여 과감히 기존 시설(예: 팔당댐의 운영, 대청댐의 운영 등)의 관리 운영 체계를 개선하여 나가야 할 것이며, 수질 보전적-환경 보전 차원에서 저수관리 체계를 확고히 할 수 있는 방안을 강구하여야 할 것이다.펄스주입법에 의해 증착된 박박은 강유전성 이력을 나타내었다.지역

• Journal of Cadastre & Land InformatiX
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• v.49 no.2
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• pp.135-149
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• 2019

This article analyzed economic effects of changes in spatial accessibility on regional touruism expenditure structure resulting from highway investments on Gangwon province, Korea. The Seemingly Unrelated Regress(SUR) model is applied to analyze the structure of change in tourism expenditure of Gangwon Province, and the competition and complementary relationship of tourist demand were analyzed among 18 counties in Gangwon by Dendrinos-Sonis method. The spatial accessibility has a significant effect on the increase in amount of tourist expenditure, but by 1% increase in the accessibility resulted in a reduction of length of stay -0.18% and travel costs -0.34% by respectively. The most powerful variable for improving the on-site economy is the tourist service establishment, which increases one unit, the amount of tourist expenditure increased by 3.6%. Moreover, the competition and supplemental relationship of tourism demands in Gangwon was decided by the conditions under which traffic flow with passing occurred, such as inland or ocean-typed travel attractions, adjacent or remote regions to the highway. The limitations of this study were not able to use raw data of tourism expenditures before and after the opening the highway due to the restriction of priority data, and further research on the appropriate level of spatial accessibility for the regional economy is needed.

• Journal of the Korean association of regional geographers
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• v.19 no.3
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• pp.384-400
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• 2013

In this study, spatio-temporal patterns of extreme precipitation events caused by typhoons are examined based on observational daily precipitation data at approximately 340 weather stations of Korea Meterological Administration's ASOS (Automated Synoptic Observation System) and AWS (Automatic Weather System) networks for the recent 10 year period (2002~2011). Generally, extreme precipitation events by typhoons exceeding 80mm of daily precipitation commonly appear in Jeju Island, Gyeongsangnam-do, and the eastern coastal regions of the Korean Peninsula. However, the frequency, intensity and spatial extent of typhoon-driven extreme precipitation events can be modified depending on the topography of major mountain ridges as well as the pathway of and proximity to typhoons accompanying the anti-clockwise circulation of low-level moisture with hundreds of kilometers of radius. Yellow Sea-passing type of typhoons in July cause more frequent extreme precipitation events in the northern region of Gyeonggi-do, while East Sea-passing type or southern-region-landfall type of typhoons in August-early September do in the interior regions of Gyeongsangnam-do. These results suggest that when local governments develop optimal mitigation strategies against potential damages by typhoons, the pathway of and proximity to typhoons are key factors.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.5
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• pp.419-425
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• 2009

Although earthquake damage was negligible in Korea during the last a few decades, its historic records suggest that the peninsula have experienced severe earthquake damages throughout the history. The potential for disastrous earthquakes, therefore, should always be considered. Harbors handle 99.6% of imported and exported cargo in Korea. Thus, it is necessary to secure the safety of harbors against seismic events and to establish a support system of emergency measures. Although instrumental seismic data are favored for seismic hazard estimation, their history in the peninsula is limited only to the past 30 years, which does not represent the long-term seismic characteristics of the peninsula. We use historic earthquakes with magnitude greater than 5 to observe long-term regional seismic hazards. Results of historic earthquake records indicate relatively high seismic hazard at harbors in Pohang, Ulsan and Incheon. Analysis of instrumental earthquake records reveal relatively high seismic hazard for harbors located along the East coast including Okgye, Mukho, Donghae, Samcheok, Pohang, and Ulsan.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.28 no.6
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• pp.375-382
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• 2016

In the present study, the wave hindcasting has been performed, and then the characteristics of storm waves at Gangnueng port was investigated, in which the high waves are observed. Comparing the numerical results with the wave measurements at Gangneung port, Niigata, and Hamada, there were good agreements between them. In particular, the Pearson correlation coefficients of significant wave heights and peak periods at Gangneung port were 0.92 and 0.72, respectively. Then the extreme wave analysis on the significant wave heights was carried out for the estimation of the frequency of storm waves. In this analysis, the storm waves over the threshold were fitted to GPD(Generalized Pareto Distribution). According to this analysis, the return period of the storm wave on February, 24, 2008, one of the large storm waves at Gangneung port, was 8.2 months. Among the computed significant wave heights larger than one-year wave, 58.3% of them were resulted from the storm, while the others were from the typhoon. Additionally, the regression analysis on the waves larger than one-month wave has been conducted, and then the relationship between the computed significant wave heights and the significant wave period, $T_{1/3}=7H_s^{0.25}$ was obtained.

• Economic and Environmental Geology
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• v.35 no.5
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• pp.455-463
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• 2002

There have been few geophysical studies on the crustal structure of the continent-ocean zone around the middle eastern part of Korean peninsula, because of the lack of database in both land and ocean. The area for the study on the internal crustal structure using gravity data is bounded by the latitude of 37$^{\circ}$-38"N and longitude of 128$^{\circ}$-132$^{\circ}$E. WCA correction is applied to shipborne gravity data to integrate with gravity anomalies obtained on land. The high frequency components of the shipborne gravity data which are considered as the noise on survey track are effectively removed by means of correlating with satellite gravity data. The corrected shipborne free-air gravity anomaly is integrated with the Bouguer gravity anomaly on land under the same condition. The integrated gravity anomaly is divided into four areas for power spectrum analysis. The depths of Moho discontinuity increases gradually from inland to Ulleung basin. As the result of modeling based on power spectrum analysis, Moho discontinuity depth is about 33-35 km in the continental zone of Korea and 18-28 km at the continental margin. Such structural character is well elucidated in changing gravity data around Ulleung basin. The depths of Moho discontinuity in the southern ocean of Ulleung-island is 16--17 km, which is much lower than in the land. The result of crustal structure modeling in this study is similar to that computed by prior seismic exploration around this area.

• Korean Journal of Environmental Biology
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• v.32 no.4
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• pp.353-362
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• 2014

In this study, we investigated the effect of geographical variations on Sargassum thunbergii morphology to make a taxonomic reconsideration about infraspecific taxa in this species. In order to examine the morphological characteristics of S. thunbergii, total 27 matured and morphologically intact thalli were collected from the east, west and south coast in spring 2011. Interestingly, it was observed that the species populations on the west coast were characterized by short, thin and coarse thallus, and soft texture. However, the populations on the east coast showed thicker thallus, larger leaf and vesicle, and tougher texture. Thallus height of S. thunbergii was found to be similar at both east and west coast. Further, the height of the thallus and lateral branch of the species populations residing south coast were highest whereas the size of leaf and vesicle are shortest, in comparison with east and west coast species. Although morphological characteristics of the north east coast populations corresponded to the original description of S. thunbergii f. latifolium, we could not find exact morphological features and diagnostic characters to distinguish form in S. thunbergii. These results indicated that it is not the optimal characteristics to identify infraspecific form in this species. In contrast, morphological variations may signify the adaptation of this species to local environmental factors. Thus, we recommend that intraspecific morphological variation of S. thunbergii should be carefully used to identify infraspecific taxa.