• Title/Summary/Keyword: SPATIAL AND TEMPORAL VARIATIONS

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Modification of Spatial Grid Based Distributed Model Considering River Basin Characteristics (유역특성을 반영한 공간격자기반의 분포형모형 개선)

  • Park, Jin Hyeog;Hur, Young Teck
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.3D
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    • pp.431-436
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    • 2008
  • Recently, the rapid development of GIS technology has made it possible to handle a various data associated with spatially hydrological parameters with their attribute information. Therefore, there has been a shift in focus from lumped runoff models to distributed runoff models, as the latter can consider temporal and spatial variations of discharge. In this research, a distributed rainfall-runoff model based on physical kinematic wave for analysis of surface and river flow was used to simulate temporal and spatial distribution of long-term discharge. The snowfall and melting process model based on Hydro-BEAM was developed, and various hydrological parameters for input data of the model was extracted from basic GIS data such as DEM, land cover and soil map. The developed model was applied for the Shonai River basin(532) in Japan, which has sufficient meteorological and hydrological data, and displayed precise runoff results to be compared to the hydrograph.

Temporal and Spatial Variations of Sea Surface Temperature in Jinju Bay in the South Coast of Korea (진주만 해역 수온의 시공간적 변동 특성)

  • Choo, Hyo-Sang;Yoon, Eun-Chan
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.21 no.4
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    • pp.315-326
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    • 2015
  • Temporal and spatial variations of surface water temperature in Jinju Bay for the period of 2010~2011 were studied using the data from temperature monitoring buoys deployed at 17 stations in the south coast of Korea. Water temperature shows the maximum late in January and the minimum early in August. Seasonal variation of water temperatures at the north part of the bay is smaller than the middle and the south. In summer, the lowest and the highest of maximum water temperature are distributed around Jijok Channel which is located at the south of the bay. The fluctuations of water temperatures at Noryang and Daebang Channel are smaller than others because of vertical mixing caused by passage of strong tidal currents. Wind and strong currents affect on the stratification of the surface water layer near Daebang Channel. High temperatures come in frequently around the north area when eastward constant flows appear at neap tide as blowing westerly in the springtime at Noryang Channel. Spectral analyses of temperature records show significant peaks at 7~20 day periods at Noryang Channel, 7~20 day and semidiurnal at the west coast of Changsun Island and Jijok Channel and 7~20 day and diurnal at the middle of the bay. Temperature fluctuation at Noryang Channel shows high coherence and has leading phase with those at other stations in the bay. However, the phase of temperature fluctuation at Noryang Channel falls behind that at Daebang Channel. Daebang Channel has an influence on the temperature fluctuation only at the west and middle part of the bay. Cross-correlation analyses for the temperature fluctuation show that Jinju Bay could be classified into six areas; Noryang Channel, the area of convergence and divergence at the north, Daebang Channel, the west coast of Changsun Island, the mixing area at the middle of the bay and the south inside of the bay, respectively.

Temporal and Spatial Variations in Sea Surface Temperature Around Boryeong off the West Coast of Korea From 2011-2012 (2011-2012년 서해 보령연안 수온의 시공간적 변동)

  • Choo, Hyo-Sang;Yoon, Eun-Chan
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.5
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    • pp.497-512
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    • 2017
  • Temporal and spatial variations in surface water temperature were studied using data from temperature monitoring buoys deployed at 47 stations around Boryeong from 2011-2012 off the west coast of Korea. Temperature fluctuations are predominant at diurnal and semidiurnal periods for all seasons, and their amplitudes are large in spring and summer but small in autumn. The maximum annual change in air temperature takes place on August 2nd and August 22th for water temperature, which means the phase for air temperature precedes water temperature by 20 days. The diurnal period of water temperature fluctuation is predominant around Daecheon and Muchangpo Harbors, with the semidiurnal period around Wonsan Island, and the shallow water constituent period on the estuary around Daecheon River. On the whole, air and water temperatures fluctuate with wind. Spectral analyses of temperature records show significant peaks at the 0.5, 1 and 15 day marks with 7-10 day periods of predominant fluctuations. Cross-correlation analyses for the temperature fluctuation show that the waters around Boryeong can be classified into four areas: a mixed water zone around the southeast side of Wonsan Island, an off-shore area to the west, an off-shore area to the south and a coastal area along the shore from Song Island to Muchangpo Harbor.

Temporal-spatial Variations of Water Quality in Gyeonggi Bay, West Coast of Korea, and Their Controlling Factor (한국 서해 경기만 연안역에서 수질환경의 시.공간적 변화 특성과 조절 요인)

  • Lim, Dhong-Il;Rho, Kyoung-Chan;Jang, Pung-Guk;Kang, Sun-Mi;Jung, Hoi-Soo;Jung, Rae-Hong;Lee, Won-Chan
    • Ocean and Polar Research
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    • v.29 no.2
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    • pp.135-153
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    • 2007
  • Temporal (seasonal) and spatial distributions and variations of various physico-chemical factors (salinity, temperature, pH, DO, COD, SPM, POC, silicate, DIP, DIN) in surface and bottom waters were studied in the coastal environment with typical macro-tidal range and monsoonal weather condition, Gyeonggi Bay, west coast of Korea. Spacial distribution patterns of these factors were generally similar to each other, and appeared to be inversely related to the distribution pattern of salinity, suggesting that water quality of the study area was primarily controlled by the physical mixing process of Han-River freshwater with nearby coastal seawater. During flooding season, silicate- and nitrogen-rich Han River water directly flowed into offshore as far as $20\sim30\;km$ from the river mouth, probably causing serious environmental problems such as eutrophication and unusual and/or noxious algal bloom, etc. Except the surface water during summer flooding season, high concentrations of nutrients appeared generally in dry season, whereas low values in spring, possibly because of the occurrence of spring phytoplankton bloom. On the other hand, nutrient flux through the estuary seems to be primarily depending on river discharge, sewage discharge and agricultural activities, especially during the rainy season. Also, nutrients in this coastal waters are considered to be supplied from the sediments of tidal-flats, which developed extensively around the Han-River mouth, especially during fall and winter of dry and low discharge seasons, possibly due to the stirring of tidal flat sediments with highly enriched pore-water nutrients by storm. And also, COD and DIN concentrations in the study area consistently increased during the last 20 years, probably because of agricultural activities and increasing discharge of industrial and domestic wastes.

Temporal and Spatial Variations of Temperature and Salinity around Ganjeol Point in the Southeast Coast of Korea (한국 남동해 간절곶 주변해역의 열염구조와 시공간적 변동 특성)

  • Choo, Hyo-Sang;Jang, Duck-Jong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.20 no.5
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    • pp.474-485
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    • 2014
  • Temporal and spatial variations of temperature and salinity around Ganjeol Point during January, April, August and November 2011 were studied using the data from CTD observations and temperature monitoring buoys deployed at 20 stations in the southeast coast of Korea. Temperature and salinity were nearly homogeneous through the whole depth by mixing of the seawater in spring and winter related to the sea surface cooling. Stratification induced by the river runoff and the bottom cold water was clear in summer. In autumn, sea water had vertical mixing initiated from surface layer and weak stratification at the middle and bottom layers. Low temperature and high salinity emerged throughout the year near Ganjeol Point, which inferred from turbulent mixing and upwelling by its topographical effect. Major periods of 1/4~1.4 day temperature fluctuations were recorded for the most part of the stations. According to the cross spectral density analysis, high coherence and small time lag for temperature fluctuation between layers were shown at Ganjeol Point. However, those features at the northen area of Hoeya river were opposed to Ganjeol Point. From analyses, thermohaline structure and its fluctuation around Ganjeol Point were characterized into those three parts, the south of Ganjeol Point, Ganjeol Point and the north of Ganjeol Point.

Effects of Physicochemical and Environmental Factors on Spatial and Temporal Variations in Phytoplankton Pigment and its Community Composition in Jinhae Bay (진해만에서 물리화학적 환경요인이 식물플랑크톤 색소 및 군집조성의 시공간적 변화에 미치는 영향)

  • Na, Sujin;Lee, Jiyoung;Kim, Jeong Bae;Koo, Jun-Ho;Lee, Garam;Hwang, Hyunjin
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.27 no.2
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    • pp.340-354
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    • 2021
  • The aim of this study was to investigate the spatial and temporal distribution of phytoplankton biomass and community composition in Jinhae Bay on the southern coast of Korea. Phytoplankton pigment analysis was conducted using ultra performance liquid chromatography (UPLC) were conducted from April to December 2019 at seven stations. Temperature, salinity, and dissolved oxygen (DO) and inorganic nutrients (dissolved nitrogen, dissolved phosphorus, and orthosilicic acid) were measured to investigate the environmental factors associated with the structure of phytoplankton community. Phytoplankton biomass (Chl-a) was the highest in July (mean 15.4±4.3 ㎍/L) and the lowest in December (mean 3.5±0.6 ㎍/L). Fucoxanthin was the most abundant carotenoid and showed a similar variation pattern to Chl-a, peridinin, and Chl-b. Phytoplankton community composition analysis showed that diatoms were a predominant group with an average abundance of 70 % whereas chlorophytes, cryptophytes, and dinoflagellates often appeared with lower averages. Further, the dominance of diatoms was closely correlated with water temperature and N:P ratio, which might be influenced by high temperatures in the summer and nutrient loading from the land. Additionally, freshwater and nutrient input by rainfall was estimated to be the most important environmental factor. Hence, the spatial and temporal variations in the composition of phytoplankton pigments and phytoplankton community were correlated with physicochemical and environmental parameters.

Remote Sensing To Study Urban Heat Island Effects in Bangkok Metropolitan Region

  • Hung, TRAN;YASUOKA, Yoshifumi
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.741-743
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    • 2003
  • This study focuses on monitoring the surface UHI in a tropical city of Bangkok in both spatial and temporal dimensions based on MODIS- and TM -derived land surface temperature (LST). The spatial extension and magnitude of the surface UHI are explored for days and nights as well as its variations through the dry (least-clouded) season. Surface UHI growth between 1993 and 2002 is mapped using highresolution LANDSAT TM thermal bands. UHI patterns are, then, analyzed in association with land/vegetation covers derived from high-resolution ETM+ and ASTER satellites and ancillary data.

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Temporal Transfer of Locomotion Style

  • Kim, Yejin;Kim, Myunggyu;Neff, Michael
    • ETRI Journal
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    • v.37 no.2
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    • pp.406-416
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    • 2015
  • Timing plays a key role in expressing the qualitative aspects of a character's motion; that is, conveying emotional state, personality, and character role, all potentially without changing spatial positions. Temporal editing of locomotion style is particularly difficult for a novice animator since observers are not well attuned to the sense of weight and energy displayed through motion timing; and the interface for adjusting timing is far less intuitive to use than that for adjusting pose. In this paper, we propose an editing system that effectively captures the timing variations in an example locomotion set and utilizes them for style transfer from one motion to another via both global and upper-body timing transfers. The global timing transfer focuses on matching the input motion to the body speed of the selected example motion, while the upper-body timing transfer propagates the sense of movement flow - succession - through the torso and arms. Our transfer process is based on key times detected from the example set and transferring the relative changes of angle rotation in the upper body joints from a timing source to an input target motion. We demonstrate that our approach is practical in an interactive application such that a set of short locomotion cycles can be applied to generate a longer sequence with continuously varied timings.

Spatiotemporal distribution of downscaled hourly precipitation for RCP scenarios over South Korea and its hydrological responses

  • Lee, Taesam;Park, Taewoong;Park, Jaenyoung
    • Proceedings of the Korea Water Resources Association Conference
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    • 2015.05a
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    • pp.247-247
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    • 2015
  • Global Climate Model (GCM) is too coarse to apply at a basin scale. The spatial downcsaling is needed to used to permit the assessment of the hydrological changes of a basin. Furthermore, temporal downscaling is required to obtain hourly precipitation to analyze a small or medium basin because only few or several hours are used to determine the peak flows after it rains. In the current study, the spariotemporal distribution of downscaled hourly precipitation for RCP4.5 and RCP8.5 scenarios over South Korea is presented as well as its implications over hydrologica responses. Mean hourly precipitation significantly increases over the southern part of South Korea, especially during the morning time, and its increase becomes lower at later times of day in the RCP8.5 scenario. However, this increase cannot be propagated to the mainland due to the mountainous areas in the southern part of the country. Furthermore, the hydrological responses employing a distributed rainfall-runoff model show that there is a significant increase in the peak flow for the RCP8.5 scenario with a slight decrease for the RCP4.5 scenario. The current study concludes that the employed temporal downscaling method is suitable for obtaining the hourly precipitation data from daily GCM scenarios. In addition, the rainfall runoff simulation through the downscaled hourly precipitation is useful for investigating variations in the hydrological responses as related to future scenarios.

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Cretaceous to Early Tertiary Granites and Magma Mixing in South Korea : Their Spatio-temporal Variations and Tectonic Implications (Multiple Slab Window Model) (남한의 백악기-제3기초 화강암과 마그마 혼합 : 시공간적 변화와 지구조적 의미(다중 슬랩 윈도우 모델))

  • Kim, Jong-Sun;Kim, Kun-Ki;Jwa, Yong-Joo;Son, Moon
    • The Journal of the Petrological Society of Korea
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    • v.21 no.2
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    • pp.203-216
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    • 2012
  • Based on the petrologic and age data of the Cretaceous to early Tertiary granites in south Korea, we propose a new tectonic model reflecting their temporal and spatial variations. A number of petrographic and geochemical studies on the granites suggest that they originated from the magma formed by subduction of oceanic crust in continental margin and were emplaced in epizone. The MMEs with various shapes and sizes, which were produced due to the magma mixing caused by the injection of mafic magma from mantle during the crystallization of the granitic magma, are observed in the granites. The distributions of the MMEs and ages of the granites show a distinctive spatio-temporal distribution pattern. The distribution pattern can be explained by a multiple slab window model related to the ridge subduction of Izanagi-Pacific plates during the Late Cretaceous.