• 제목/요약/키워드: soil temperature distribution

검색결과 227건 처리시간 0.031초

Use of uniform distribution for generating synthetic brightness temperature in passive microwave soil moisture retrieval

  • Lee Khil-Ha
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2005년도 학술발표회 논문집
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    • pp.19-28
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    • 2005
  • Passive microwave remote sensing technique have shown great potential for mon monitoring regional/global surface soil moisture. Given a single measurement at dual polarization/single frequency/single view angle, a strategic approach to artificially generating multiple microwave brightness temperatures is presented. And then the statistically generated microwave brightness temperature data are applied to the inverse algorithm, which mainly relies on a physically based microwave emission model and an advanced single-criterion multi-parameter optimization technique, to simultaneously retrieve soil moisture and vegetation characteristics. . The procedure is tested with dual polarized Tropical Rainfall Measurement Mission Microwave Imager (TRMM/TMI) over two different cover sites in Oklahoma and Beltsville field experimental data. The retrieval results are analyzed and show excellent performance.

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남극 및 시베리아 흙의 동토공학적 특성 분석 (Engineering Characteristics of Antarctic and Siberian Frozen Soils)

  • 김영진;신재원;김현기
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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    • pp.894-904
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    • 2008
  • In this study, soil samples from the Antarctic and Vladivostok, Siberia were tested in the laboratory, and specific gravity, compaction curve and grain size distribution were determined. The effect of temperature change on the thermal conductivity, unfrozen water content and compressive strength were investigated. Samples for the compressive strength test were prepared in a mold with a fixed volume to prevent swelling and the effect of temperature and water content change on the strength were compared. Results from the thermal conductivity test showed that thermal conductivity values for both soils were larger at temperatures below freezing than above freezing. The unfrozen water content dropped sharply within a temperature range of $0{\sim}-5^{\circ}C$ and then gradually decreased further up to $-20^{\circ}C$. Compressive strength test results showed various stress/deformation curves with a change in water content. Sandy soil had much larger strength than pure ice at an identical temperature, while clayey soil had a smaller strength than ice near the freezing point, but showed a larger strength at temperatures belows $-15^{\circ}C$.

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식물의 온도 완화효과에 관한 기초적 연구 (A Quantitative Study on the Effect of Temperature Control by a Shade Tree and the Lawn Area)

  • 안계복;김기선
    • 한국조경학회지
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    • 제14권1호
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    • pp.1-13
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    • 1986
  • The purpose of this study is to investigate the effect of temperature control by a shade tree and the lawn area. In this investigation, we find out that artificial-lawn, concerte, and exposed soil are more higher temperature than covered with plant materials. The results of the measurement may to summerized as follows; 1) Low-temperature effects of zoysia japonica is more controlled by condition of growth than leaf length of grass. Surface temperature make 0.7$^{\circ}C$ difference between long grass (15cm), and short grass (5cm), but make 5$^{\circ}C$ difference between good growth grass (230/10$\textrm{cm}^2$) and bad growth grass (80/10$\textrm{cm}^2$). 2) The surface temperature of the lawn area is 40.5$^{\circ}C$ lower on a maxinum than that of the artificial lawn (July 28, 1985). During the day of summer, shade area under the shade tree is 0.9$^{\circ}C$ lower then lawn area surface temperature, 6.9$^{\circ}C$ lower than bad growth lawn, 10.3$^{\circ}C$ lower than exposed soil, and 18$^{\circ}C$ lower than concrete surface temperature. 3) Natural irrigation effect on the surface temperature fluctuation. But this effect is changed by compositions of ground materials and time-lapse. 4) Sunny day is more effective than cloud day. 5) In summer season, surface temperature make a difference compare to temperature of 0.5-1.5m height from ground : Surface temperature is 3.4$^{\circ}C$ lower at the lawn area (11 a.m.), 4.2$^{\circ}C$ lower at the shade area the shade tree, 12.7$^{\circ}C$ higher at the concrete area (3p.m.), 38.8$^{\circ}C$ higher at the artificial lawn (2p.m.) 6) According to compositions of ground materials and season have specific vertical temperature distribution curve. 7) In summer season, temperature distribution of 0.5-1.5m hight at the shade tree is 4.8-5.7$^{\circ}C$ lower than concrete area (noon-3p.m.)

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인공신경망을 이용한 용담댐 유역 공간 토양수분 분포도 산정 (Estimation of Spatial Distribution of Soil Moisture at Yongdam Dam Watershed Using Artificial Neural Networks)

  • 박정아;김광섭
    • 대한지리학회지
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    • 제46권3호
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    • pp.319-330
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    • 2011
  • 본 연구에서는 지상관측 토양수분, 강수량, 지면온도 및 MODIS NDVI와 인공신경망모형을 이용하여 토양수분 공간분포 산정 모형을 제안하였으며, 신뢰성 높은 토양수분 관측 자료를 보유한 용담댐 유역에 대하여 모형의 적용성을 검증하였다. 토양수분 산정모형의 학습에 사용된 주천, 부귀, 상전의 3개 지점의 경우 약 0.9353의 상관계수와 약 1.4957%의 평균제곱근오차를 보여주며, 검증지점으로 사용된 천천2의 경우에는 약 0.8215의 상관계수와 약 4.2077%의 평균제곱근오차를 보여 토양수분 산정모형의 적용가능성이 높다고 판단된다. 인공위성으로부터 관측된 광역의 식생정보와 자료간의 비선형 상관특성을 잘 구현하는 인공신경망을 활용하여 수립된 토양수분 산정모형을 이용하여 용담댐 유역의 토양수분 공간분포도를 산정한 결과, 용담댐 유역의 대부분을 차지하고 있는 산림지역의 토양수분이 다른 지역에 비하여 높은 수치를 보여주는 토양수분의 분포를 보여주었다. 본 연구를 통해 제시된 토양수분 산정 방법은 광역 토양수분 산정에 유용한 접근법으로 판단된다.

리기다소나무림 부식토내의 Cellulase , Xylanase 의 활성과 토양미생물의 연간변동과 수직분포 (Annual Fluctuations and Vertical Distributions of Cellulase, Xylanase Activities and Soil Microorganisms in Humus Horizon of a Pinus rigida Stand)

  • Chang, Nam-Kee;Jun Hi Yoo
    • The Korean Journal of Ecology
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    • 제9권4호
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    • pp.231-241
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    • 1986
  • The annual decomposition of cellulose and hemicellulose by microorganism and distribution of soil microbial flora were investigated in the humus horizon of a Pinus rigida stand in Mt. Kwanak. The cellulase activity was the lowest, 142$\mu$g glucose/g/hr from Dec. 1985 to Mar. 1986 and the highest, 760~1, 072$\mu$g glucose/g/hr in Jul. and Aug. 1985. The xylanase activity was 47% higher than the cellulase activity and was the lowest, 211~275$\mu$g xylose /g/hr from Feb. to Mar. 1986 and the highest as 799~1, 322$\mu$g xylose/g/hr from Jun. to Aug. 1986. The vertical distribution of the enzyme activity was decreased with the order of F, H, L, and A1 in both enzymes and the activities were exponentially decreased below L horizon, which suggests that most decomposition be done in F and H horizons with lots of organic matters. The SEM study slowed that the main decomposers of litters were fungi and initial attack into litters was also made by them. The enzyme activities of soil had strong correlations with the temperature and the precipitation. The correlation coefficients were 0.813 and 0.886 in the cellulase, and 0.673 and 0.626 in the xylanase for the temperature and the precipitation, respectively.

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環境傾度에 의한 母岳山 植物個體群의 分布類型 (Distribution patterns of specice populations along the environmental gradients in mt. moak provincial park, korea)

  • Kim, Jeong-Un;Yim, Yang-Jai
    • The Korean Journal of Ecology
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    • 제15권4호
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    • pp.365-375
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    • 1992
  • The environmental gradient analyses were applied for the distribution patterns of species populations in mt. moak provincial park in korea. The species populations were sequentially ordered along the environmental gradients such as soil moisture, soil ph, soil organic matter content and elevation and were grouped into seven ecological groups by the two-dimensional analyses of temperature-moisture gradient : zelkova serrata group on mesic-lower parts near the streames and well drained stony slopes, carpinus tschonoskii group on mesic-middle parts, quercus acutissima group on lower parts destroyed by human activities, quercus variabilis group on xeric-middle parts, quercus serrata group on xeric-upper middle parts, quercus mongolica group on xeric-upper parts and pinus densiflora group on xeric-rock ridge lines, hillocks and lower parts interfered by human. Four forest vegetation types, zelkova forest dominated by the c. tschonoskii group on mesic-middle parts, oak forest dominated by the groups of q. acutissima, q. variabilis, q. serrata and q. mongolica on xeric sites and pine forest dominated by the p. densiflora group on dry and poor sites, were separated in mosaic chart by the two-dimensional analysis.

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제주한란의 자생환경 특성 및 분포에 관한 연구 (Habitat Characteristics and Distribution of Cymbidium kanran Native to Jejudo, Korea)

  • 이종석
    • 한국환경복원기술학회지
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    • 제7권1호
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    • pp.40-49
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    • 2004
  • This work carried out to define the characteristic of Cymbidium kanran habitat at Mt. Halla in Jejudo, Korea from the ecological point of view including geological and topographical features, air and soil temperature, relative humidity, fluctuations of light intensity, habitat vegetation, distribution altitude, area limit, and etc. And another goal of this study consider the conservation counterplan of the cymbidium habitat. Natural distribution areas of the cymbidium were observed more abundantly on the well drained south and east-facing slopes. Soil acidity was ranged from pH 4.1 to 5.3, and electric conductivity was ranged from 176.4 to 299.9 us/cm (average 215.3 us/cm). Base-saturation percentage of the habitat soil was below 50%, bulk density 0.42g/$cm^2$, particle density 2.05g/$cm^2$, humus content 26%, total nitrogen 0.82%, available phosphate 4.2 mg/kg, exchangeable potassium 0.63 Cmol/kg, calcium 0.44 Cmol/kg and magnesium 0.67 Cmol/kg. Annual mean air temperature was $15.4^{\circ}C$, however, air temperature was ranged $11.7{\sim}18.2^{\circ}C$ in spring, $21.2{\sim}23.8^{\circ}C$ in summer, $12.8{\sim}22.0^{\circ}C$ in fall and $5.5{\sim}7.8^{\circ}C$ in winter season. Annual mean soil temperature at depth of 10cm was $13.2^{\circ}C$ And minimum value was recorded $4.7^{\circ}C$ on January, and maximum value $22.5^{\circ}C$ on August. Relative humidity was ranged 90.8~94.7% in summer, 80.8~91.5% in fall and 77.6~84.2% in winter season. Minimum value was 56.5% on December, and maximum value was 100% on July and August. Light intensities were ranged from 400 to 1,800 lux at the greater part of Cymbidium kanran sites in Jejudo. Summer regarded as an lower light intensities was recorded to be range of 500~600 lux; however, autumn and winter were shown higher light regimes ranged from 3,500 to 3,800 lux. Therefore, one must be suprised that the cymbidium grow at the light condition of 6 lux (minimum) or 10,000 lux (maximum). Tree species keeping higher frequency rate and density were Eurya japonica, Camellia japonica, Castanopsis cuspidata, Carpinus laxiflora and Pinus densiflora. Number of trees growing in a 5${\times}$5m quardrat was 35 as an average, and proportion of evergreen versus deciduous was 5:1. Distribution altitude of the orchid habitat was ranged from 120m (low) to 840m (high) from sea level on the south facing slope of Mt. Halla, and was ranged eastern borderline of Gujwaup, Bukjejugun to western boundaries of Jungmundong, Seogwipo city. For the stable conservation of Cymbidium kanran habitat, sunlight regimes must be increased more by means of cutting trees or twigs in the site.

CFD를 이용한 기상청 지중온도의 피트부분 지중열원 유용성 평가에 관한 연구 (Effectiveness Assessment on the Soil Temperature of KMA as Ground Heat Source Using CFD in Pit Area)

  • 민준기;김정태
    • KIEAE Journal
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    • 제8권5호
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    • pp.49-54
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    • 2008
  • The experimental of temperature, humidity and velocity was taken from the underground pit which utilized the system of ground heat source quite similar to the cool-pit system. Also, through CFD analysis, one could review the effectiveness of analysis of future alternatives. Furthermore, the temperature range of mock up cool-pit system was analyzed by inputting the weather data of annual average soil temperature provided by KMA(Korea Meteorological Administration) into the fluid simulation of anticipated heat distribution. Firstly, the difference between the temperature of air exhaust of the pit or the temperature of air supply of the compressor room and the experimental data for the month of May from the CFD analysis came out to be $0.6^{\circ}C$ and $0.9^{\circ}C$ respectively with tolerance of 3.1% and 4.7%. Secondly, the difference between the temperature of air exhaust of the Pit or the temperature of air supply of the compressor room and the experimental data for the month of July from the CFD analysis came out to be $0.8^{\circ}C$ and $1.1^{\circ}C$ respectively with tolerance of 3.3% and 4.5%. Thirdly, for the month of May, the difference between the experimental data taken for the air exhaust of the Pit or the air supply of the compressor room and soil temperature provided by KMA for monthly and yearly average temperature of Jeonju region came out be $1.9^{\circ}C$ and $1.8^{\circ}C$ respectively with tolerance of 10.7% and 9.8%. Fourthly, for the month of July, the difference between the experimental data taken for the air exhaust of the Pit or the air supply of the compressor room and soil temperature provided by KMA for monthly and yearly average temperature of Jeonju region came out be $1.1^{\circ}C$ and $1.4^{\circ}C$ respectively with tolerance of 4.5% and 5.8%. The result of above experiments allowed us to establish CFD model set up as a verification tool that is based on experimental data collected within the Pit area. Also, one could confirm the possibility to apply weather data of soil temperature provided by KMA in order to anticipate proper value for CFD analysis.

식피별 비공생성 호기성 질소고정세균의 변동에 관하여 (Studies on the fluctuation of aerobic free-living nitrogen fixation bacteria in soil beneath the plant covers)

  • 이태우;심재국
    • 미생물학회지
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    • 제21권2호
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    • pp.71-78
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    • 1983
  • The number of aerobic free-living nitrogen fixation bacteria and factors in soil at different stands covered with Pinus rigida, Quercus acutissima and Zoysia japonica in Cheongju area were investigated from Feb. to Sept 1981. 1. The numbers of $N_2-fixation$ bacteria, according to the seasonal changes, increased gradually from winter to spring and summer. But the growth pattern revealed some differences in accordance with plant cover stands : the numbers increased abruptly in May at Pinus, May-June at Quercus and Apr. May at Zoysia stand. The pick of numbers represented in Aug. Sept, at Pinus, Jul-Aug. at Quercus and May-Jun. at Zoysia stand, respectively. 2. The interrelationship between the monthly changes of enviotnmental factors and numbers of $N_2-fixation$ bacteria at different stands, mainly depends upon the soil temperature than other soil factors (r=0.71-0.84). The numbers of $N_2-fixation$ bacteria may increase 5-7 times according to increase $10^{\circ}C$ of soil temperature, and optimal range was $20{\sim}30^{\circ}C$ for growth. Equation of the interrelation between soil temperature and numbers could be stated as follows : log y=ax+b. 3. In the case of high soil temperature, the bacterial numbers presented high level in drought periods. Therefore, the $N_2-fixation$ bacterial species in these soil seem to consist of resistant to desication. 4. The influence of soil organic matter for growth of $N_2-fixation$ bacteria indicated low conrelation. The reason may seen the content of organic matter in these soil existed abundantly above the quantities of limitation for growth. 5. In artifical gradients, the $N_2-fixation$ bacteria were predominated at $20{\sim}30^{\circ}C$ same as natural condition, pH7-8, and 20-30% of soil water contents. 6. The vertical distribution of bacteria marked decreasing trends from surface to lower layers, and the decreasing degree was shown well in Zoysia, Quercus and Pinus stand in order. But in the trees, the numbers increased at 30cm layer estimated the region of root than 20cm layer. 7. Both catalase megative and positive group of $N_2-fixation$ bacteria in soil increased according to the rise of the soil temperature. Catalase positive group was revealed as dominant group in winter, and catalase negative group revealed in summer. The change of dominant pattern was shown during Feb. to Apr.

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복주머니란 (Cypripedium macranthum Sw.)자생지의 생육환경에 관하여 (Growth Environments of Cypripedium macranthum Sw. Habitats in Korea)

  • 김지연;이종석
    • 원예과학기술지
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    • 제16권1호
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    • pp.30-32
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    • 1998
  • 경기도 북부 및 강원도 산악지대에 많이 분포되어 있는 복주머니란의 자생지 생육 환경을 파악하여 재배화를 위한 기초자료로 활용하고자 본 실험을 실시하였다. 복주머니의 자생지의 연평균기온은 $14^{\circ}C$이며, 기온이 가장 낮은 시기는 1월로써 $-7^{\circ}C$었으며, 8월에는 $28^{\circ}C$였다. 자생지의 연평균 저온은 $10.9^{\circ}C$이였으며, 1월에 최저 $-4^{\circ}C$를 나타내었다. 양지에서의 광도는 3월과 5월 사이에 48,000 lux~51,433 lux였으며, 7월에 11,500 lux로 가장 낮았다. 한편 음지에서는 7월과 8월에 광도가 급격히 떨어져 470~865 lux범위로 매우 낮았고, SPAD값은 7월에 34.3으로서 년중 가장 높았다. 자생지 토양 산도는 pH 5.6~5.8 범위이며, 토양수분은 16.4 %~36.2%이었고, 6월에 36.2%로 가장 높았다.

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