2018년 금강 하구해역 식물플랑크톤 군집의 시·공간적 분포 및 생물해양학적 환경특성

김혜선,김하련,양동우,윤양호,Kim, Hye Seon,Kim, Haryun,Yang, Dongwoo,Yoon, Yang Ho 한국환경생물학회 2020 환경생물 : 환경생물학회지 Vol.38 No.2

We conducted a seasonal field survey to analyze the distribution patterns of a phytoplankton community and biological oceanographic characteristics in the Geum river estuary in 2018. The results showed that the phytoplankton community consisted of 58 genera and 116 species, showing a relatively simple distribution. It was controlled by diatoms at 70.2%, a low number of species in winter and spring, and a high number in summer and autumn. The phytoplankton cell density ranged from 10.0 to 2,904.0 cells mL^-1, with an average layer of 577.2 cells mL^-1, which was low in autumn and high in winter. The seasonal succession of phytoplankton dominant species was mainly centric diatoms from winter to summer, including Thalassiosira nordenskioeldii, Cerataulina bergonii, and Skeletonema costatum-ls in winter, S. costatum-ls and C. bergonii in spring, and Eucampia zodiacus and Th. nordenskioeldii in summer. However, the autumn species depended upon the regions, with the inner bay dominated by the centric diatom, Aulacoseira cf. granulata, the mixed areas by S. costatum-ls, and the open sea by the dinoflagellate, Lingulodinium polyedra. According to principal component analysis (PCA), the phytoplankton community was greatly affected by the inflow and expansion of freshwater, including high nutrients, which are introduced annually through the rivermouth weir in Geum river estuary. However, the estuary, which is strongly affected by annual freshwater, was limited to areas near Geumran Island, which is adjacent to the river-mouth weir. 금강 하구해역 식물플랑크톤 군집의 시·공간적 변동 및 생물해양학적 환경특성을 파악하기 위해 2018년 2월, 5월, 8월 및 11월, 4계절에 거쳐 15개 정점을 대상으로 현장조사를 실시하였다. 조사기간 동안 출현한 식물플랑크톤 종은 58속 116종으로 겨울과 봄에 단순하였고, 여름과 가을에 상대적으로 다양하게 출현하였다. 현존량은 가을에 10 cells mL^-1에서 겨울에 2,904.0 cells mL^-1까지 큰 변동 폭으로 평균 577.2 cells mL^-1의 높은 현존량을 보였으며, 출현 종과는 달리 봄과 가을에 낮고, 여름과 겨울에 높은 현존량을 나타내었다. 우점종은 연중 규조류 점유율이 높았으며, 겨울은 Thalassiosira nordenskioeldii, Cerataulina bergonii, Skeletonema costatum-ls 및 Coscinodiscus angustelineata, 봄은 S. costatum-ls 및 C. bergonii, 여름은 Eucampia zodiacus 및 Th. nordenskioeldii, 그리고 가을 하구역은 Aulacoseira cf. granulata, 혼합해역은 S. costatum-ls 및 외해역은 Lingulodinium polyedra가 우점하였다. 그리고 주성분 분석에 의하면 금강 하구해역의 식물플랑크톤 군집은 연간 금강하굿둑을 통해 유입되는 높은 영양염을 포함하는 담수의 유입량과 확장 정도에 크게 영향을 받고 있었다. 그러나 하굿둑을 통한 직접적인 담수 영향은 금란도 주변까지의 영역에 한정되었고, 그 외 해역은 해수와 담수가 강하게 혼합되었다.

A temporal–spatiotemporal domain transformation-based modeling method for nonlinear distributed parameter systems

Jin Xi,Wu Daibiao,Yang Haidong,Zhu Chengjiu,Shen Wenjing,Xu Kangkang 한국CDE학회 2023 Journal of computational design and engineering Vol.10 No.3

Complex nonlinear distributed parameter systems (DPSs) exist widely in advanced industrial thermal processes. The modeling of such highly nonlinear systems is a challenge for traditional time/space-separation-based methods since they employ linear methods for the model reduction and spatiotemporal reconstruction, which may lead to an inefficient application of the nonlinear spatial structure features represented by the spatial basis functions. To overcome this problem, a novel spatiotemporal modeling framework composed of nonlinear temporal domain transformation and nonlinear spatiotemporal domain reconstruction is proposed in this paper. Firstly, local nonlinear dimension reduction based on the locally linear embedding technique is utilized to perform nonlinear temporal domain transformation of the spatiotemporal output of nonlinear DPSs. In this step, the original spatiotemporal data can be directly transformed into low-order time coefficients. Then, the extreme learning machine (ELM) method is utilized to establish a temporal model. Finally, through the spatiotemporal domain reconstruction based on the kernel-based ELM method, the prediction of the temporal dynamics obtained from the temporal model can be reconstructed back to the spatiotemporal output. The effectiveness and performance of the proposed method are demonstrated in experiments on the thermal processes of a snap curing oven and a lithium-ion battery.

Spatiotemporal Distribution of Gastrointestinal Tract Cancer through GIS over 2007-2012 in Kermanshah-Iran

Reshadat, Sohyla,Saeidi, Shahram,Zangeneh, Ali Reza,Khademi, Nahid,Khasi, Keyvan,Ghasemi, SayedRamin,Gilan, Nader Rajabi Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.17

Background: Cancer is one of the common causes of disability and mortality in the world. The present study aimed to define the spatiotemporal distribution of gastrointestinal tract cancers using a geographic information system (GIS) over the time period of 2007-2012 in Kermanshah-Iran. Materials and Methods: The method of studying was descriptive-analytical as well as comparative with gastrointestinal tract cancer patients based in the City of Kermanshah over the time period covered. For data analysis, the GIS and SPSS 16.0 were applied. Results: According to the pathological reports within the space of 5 years, 283 cases of gastrointestinal tract cancer (157 in males, 156 in females) were reported. The performed tests in terms of spatial distribution in the environment of GIS indicated that the disease demonstrated a clustered pattern in the City of Kermanshah. More to the point, some loci of this disease have emerged in the City of Kermanshah that in the first level, 6 neighborhoods with 29-59 cases of this disease per square kilometer and in the second level, 15-29 cases. Conclusions: Gastrointestinal tract cancer demonstrated an ascending trend within the space of 5 years of research and the spatiotemporal distribution of cancer featured a concentrated and clustered pattern in the City of Kermanshah.

남해안 봉강천과 미룡천 하구에서 기수갈고둥의 분포 및 서식지 환경 특성

장건강,김민섭,조수근,이원호,김형섭 한국해양과학기술원 2021 Ocean and Polar Research Vol.43 No.3

At the estuaries of Bonggang and Miryong streams in the Korean southern coast, the spatiotemporal distribution and habitat environment of a nerite snail, Clithon retropictum (Gastropoda: Neritidae), which has been assigned as a legally protected species of Korea, were explored. Physicochemical environmental factors such as water temperature, salinity, tidal level distribution as well as biotic environments (chlorophyll-a concentration and epilithic microalgae composition) were monitored every month. The relationships between the environmental factors and spatiotemporal distribution of the nerite snail population were analyzed. Water temperature, salinity, and water level varied by season and lunar tidal rhythm. The spatiotemporal distribution of the nerite snail was mostly related to water salinity. Among epilithic algae which were the priority prey of snails, blue-green algae and green algae dominated in summer and autumn, while diatoms predominated during winter and spring. Chlorophyll-a concentration was highly and positively correlated with the population density of the nerite snail. The correlation coefficients were different depending on the taxon (Family) of epilithic algae. The mean population density was 302.2 inds m-2 and 271.8 inds m-2 in Bonggang Stream and Miryong Stream, respectively. The egg capsules of the nerite snail in the two habitats were observed from March (in Bonggang Stream) or April (in Miryong Stream) to August, and newly hatched juveniles recruited in the habitats from August were assessed with regard to frequency distributions of shell width. The occurrence of large-sized snails in upper stream reaches of both Bonggang and Miryong indicated the movement of spats from the mouth to the upper reaches during the whole life cycle.

Impacts of environmental and anthropogenic stresses on macrozoobenthic communities in Jinhae Bay, Korea

Bae, Hanna,Lee, Jung-Ho,Song, Sung Joon,Park, Jinsoon,Kwon, Bong-Oh,Hong, Seongjin,Ryu, Jongseong,Choi, Kyungsik,Khim, Jong Seong Elsevier 2017 CHEMOSPHERE - Vol.171 No.-

<P><B>Abstract</B></P> <P>In this study, spatiotemporal dynamics of macrofaunal assemblages and their associations with environmental conditions were examined in Jinhae Bay (10 sites), where the obvious sources of pollution including industries, oyster farms (hanging cultures), and municipal discharges has surrounded. The survey had performed over five consecutive seasons in 2013–2014. Target sedimentary variables included grain size, organic content, C/N ratio, carbon and nitrogen stable isotope ratios, and some heavy metals. Five ecological quality indices (EcoQ) were calculated from the benthic community data to evaluate ecological qualities in site-specific manner. Jinhae Bay is a shallow (depths range, 11–24 m) and typical semi-enclosed bay. The benthic environments represented mud dominated bottoms (>70%) with fairly substantial organic content levels (>2%) over all five seasons. Seasonal patterns were observed with peak abundances in the spring and distinctive macrozoobenthos species shifts in the summer. The spring bloom could be explained by drastic increases of some polychaetes, mainly <I>Capitella</I> sp., at certain site, particularly near the shore. The oyster farms situated in the innermost locations seem to provide organic-rich bottoms being dominated by opportunistic species and/or organic pollution indicator species, such as <I>Lumbrineris longifolia</I>, <I>Capitella</I> sp., and <I>Paraprionospio patiens</I>. In general, the EcoQ indicators indicated that Jinhae Bay was moderately polluted, with exceptionally poor EcoQ in a few locations during the specific season(s). Overall, adverse effects on benthic community was broadly attributable to contaminations of heavy metals and nearby aquatic farm activities in Jinhae Bay, which requires a prompt action toward ecosystem-based management practice in the given area.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Spatiotemporal dynamics of macrofaunal assemblages in Jinhae Bay were addressed. </LI> <LI> Peak abundances in spring and distinctive species shifts in summer were characteristic. </LI> <LI> Oyster farming was one potential anthropogenic stress affecting macrofaunal communities. </LI> <LI> Analysis of five ecological quality indices indicated moderate pollution in given area. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A Long-Term Monitoring of Major Hydrovariables and its Spatiotemporal Variabilities - A Study from the Korean Riverine Systems

Ki-Hyun Kim(김기현),Jong-Min Oh(오종민) 상지대학교 환경과학기술연구소 1997 환경과학연구 Vol.3 No.1

  1984년부터 1993년까지 한강 및 낙동강 수계의 수질자료에 대한 분석을 지역적 및 시간적 배경을 중심으로 실시하였다. 월별 및 계절별 분석에 의하면, 온도, 유속, 용존산소량 등의 변수는 수계에 상관없이 규칙적인 분포양상을 띄었다. 그러나 더 장기적인 주기로 분석하였을 때는 수계에 따라 훨씬 다양한 결과를 보여 주었다. 한강지역의 경우, TN과 TP가 규칙적인 변화를 보인데 반해, 낙동강지역은 시간의 경과와 함께 농도의 지속적인 증가경향을 보여주었다. 두 수계에 대해 상하류를 중심으로 상관성을 분석한 결과는 낙동강 지역에서 강한 상관성이 존재한다는 것을 확인할 수 있었다. 낙동강에서 측정한 수질변수들이 높은 상관성을 보이는 것은 호수와 같은 낙동강의 지형적 특성에 의한 것으로 사료된다. 이와 같은 수질변수의 분포경향 및 상관성 분석을 통해 이들 지역의 수질분포는 대단히 복잡한 요소들에 의해 조절된다는 것을 입증할 수 있었다.   To investigate both short- and long-term distribution characteristics of several major water-quality variables, we conducted a series of statistical analyses on the data sets collected from both up- and downstream stations of the Han (HR) and Nak Dong River (NOR) over a ten year period (1984 through 1993). A comparison of the data over different time scale revealed several important aspects of their temporal distribution characteristics. The analysis of monthly, or seasonal, trends indicated that variables like temperature, flow rate, and DO display most periodically reproducible patterns, regardless of geographical locations. The analysis of long-term distribution trends of those variables indicated quite contrasting features between the two rivers: TN and TP levels of the HR did not show any systematic patterns over time, while their counterparts for the NOR exhibited a consistently increasing pattern over the study periods. When the data for each river were analyzed between up- and downstream waters, correlations were found more abundantly from the NOR than from the HR. The observations of enhanced spatial homogeneity in the former is likely to come from the shallow, lake-like geographical characteristics of the Nak Dong River. Results of our correlation analyses also indicated the possibility that some biochemical (e.g., DO, COD, and SS) and physical parameters (temperature, flow rate) may be affected in similar manners. Such relationships were most frequently seen from the downstream waters of the HR due probably to effective mixing of water in that area. The overall results of our study on the water-quality conditions in the two major riverine systems show that their distributions are controlled by the mixed effects of various physicochemical properties.

21년간 한국의 서리발생 시⋅공간 분포 특성과 경향

조은수,김해민,신주영,김규랑,이용희,지준범 한국농림기상학회 2022 한국농림기상학회지 Vol.24 No.2

In order to actively prepare to frost damage that occurs in the process of growing crops, the spatial and temporal distribution of frost occurrence in South Korea was derived using frost observation data from 20 regions over the past 21 years (2000∼2020). The main products are the number of frost days, first frost day, and last frost day by region. And the climatic trends of these results were identified by performing the Mann-Kendall trend test and Sen’s slope estimator. In South Korea, a lot of frost occurs in the inland area to the west of the Taebaek and Sobaek Mountains. Relatively closer to the coastal area, the number of frost days is small, the first frost day is slow, and the last frost day is early. The east coast region has fewer frost days, the first frost day is later, and the last frost day is earlier than the west coast region. The southern sea, the southeastern sea region, and the island region rarely experience frost. As a result of the annual time series trend analysis, although South Korea is a country where climate warming is progressing, there was no trend in reducing the number of frost days and slowing the first frost day, and it was found that the last frost day is delayed by 0.5 days per year. 농작물 생육 과정에서 서리에 의한 동상해 피해에 능동적으로 대비하기 위해, 지난 21년간(2000∼2020) 20개 지역의 서리관측 자료를 이용하여 한국 서리발생의 시공간적 분포 특성을 살폈다. 지역별 서리분포 특성은 서리일수, 첫 서리일, 끝 서리일로 표현하였다. 그리고 이러한 결과의 기후 경향은 Mann-Kendall trend test와 Sen’s slope estimator를 수행하여 확인하였다. 한국에서 대부분의 서리는 태백산맥과 소백산맥 서쪽 내륙지방에서 발생한다. 상대적으로 해안지역에 가까울수록 서리 발생일이 적고 첫서리일이 느리며 끝 서리일이 빠르다. 동해안지역은 서해안지역보다 서리일수가 적고 첫서리일이 느리며 끝서리일이 빠르다. 남해, 남동해, 도서지역은 거의 서리가 발생하지 않는다. 연간 시계열 추이 분석결과 한국은 기후온난화가 진행됨에도 불구하고, 서리일수가 줄어들거나 첫서리일이 늦춰지는 경향은 나타나지 않았으며, 끝서리일은 1년에 0.5일씩 늦춰지는 것으로 나타났다.

CFD-DEM 연동을 통한 함정용 채프운의 시공간 분포 해석

정욱진,김문홍,손동우 한국전산구조공학회 2023 한국전산구조공학회논문집 Vol.36 No.2

수많은 함정용 채프들은 폭발에 의해 확산되어 채프운을 형성하며, 채프운은 허위 레이더 반사 단면적을 생성하여 적의 레이더를 기만한다. 본 논문에서는 전산유체역학-이산요소법 단방향 연동 기법을 기반으로 공기 중에 분포하는 함정용 채프운의 시공간 분포를 해석하는 수치적 프레임워크를 구축하고 바람의 방향과 속도, 채프 카트리지의 초기 각도와 폭발 압력이 채프운 분포에 미치는 영향을 분석하였다. 채프운의 확산은 폭발에 의한 방사형 확산, 난류와 충돌에 의한 전 방향 확산, 낙하 속도 차이에 의한 중력 방향 확산과 같이 세 단계로 구분되는 것을 확인하였다. 바람은 채프운의 평균 위치를 이동시켰으며, 항력에 의한 확산 효과는 나타나지 않았다. 카트리지 초기 각도에 따라 폭발에 의한 방사형 확산 방향이 달라졌으며, 각도가 지면과 수직에 가까울수록 더 넓게 확산되었다. 폭발압력이 증가할수록 채프운은 더 넓게 확산되었으나 중력 방향으로는 분포 차이가 작았다.

Distribution and Density of Coastal Fish in the Asan Bay, Korea, estimated Hydroacoustic Survey

Hyungbeen Lee,Donhyug Kang,Yangjae Im,Kyounghoon Lee 한국수산과학회 양식분과 2014 한국수산과학회 양식분과 학술대회 Vol.2014 No.7

GIS 및 관망해석모델을 이용한 도시 배급수 공급계통의 잔류염소농도 및 수질 중점관리구역 공간분석

이주원 ( Juwon Lee ),정기문 ( Gimoon Jeong ),강두선 ( Doosum Kang ),황태문 ( Tae-mun Hwang ) 한국물환경학회 2022 한국물환경학회·대한상하수도학회 공동 춘계학술발표회 Vol.2022 No.-