• Journal of Environmental Policy
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• v.12 no.1
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• pp.59-74
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• 2013

The weakness of current water quality monitoring system was reviewed to manage Nakdong river's water quality. The current monitoring system has sampling periods lasting for a week to 10 days, but these-SAMpling periods may not accurately measure the real level of water quality. Therefore, daily sampling and analysis of water samples for nine factors was performed from May 1st 2011 to Sep. 30st 2011 to check the water quality changes at three-SAMpling points, Munsanri (the upper side of Kangjung-Koryung weir), Kangchang (the outlet of the Kumho River) and Samunjin (the lower side of Kangjung-Koryung weir). As demonstrated by the results, concentrations of all nine factors dramatically changed on a daily basis, so daily sampling and analysis of water quality samples may be needed instead of weekly sampling and analysis of water quality samples to ensure the proper management of the Nakdong River's water quality. However, daily observations for all water sampling points are not possible because costs and labors are limited, so that new methods which could support the current monitoring system should be developed.

• Journal of the Korean earth science society
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• v.21 no.3
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• pp.258-275
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• 2000

The purpose of this study is to investigate diurnal variations of snowstorm occurred along the East Coast of the Korean Peninsula. The snowstorm which occurred on 5${\sim}$7 January 1997 have been analyzed. The pressure patterns were analyzed through surface and upper-air chart(850hPa). Diurnal variations of four areas, i. e. Youngdong, Mt. Taebaek, Youngseo and Kyungbuk regions were analyzed through wind direction and speed, cloud amounts, surface temperature, dewpoint temperature, relative humidity and sea level pressure. And snowfall amounts over four areas were analyzed through regional distribution, daily and temporal variations. The snowfall which occurred on January 5 was caused by the weak low pressure which is located in Kyusu region of Japan. The snowfall of January 6 occurred due to the Siberian high's expansion and instability. And northeasterly wind is one factor of the snowstorm which occurred in Mt. Taebaek region on 7 January. Heavy snowfall was caused by westerly wind but easterly wind occurred weak snowfall in Youngdong area. The precipitation of Kyungbuk region(eapecially, Pohang) was less than that of Youngdong region because the air mass which was not modified had influence on Kyungbuk region on 6${\sim}$7 January, 1997.

• Korean Journal of Remote Sensing
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• v.28 no.1
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• pp.1-9
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• 2012

The diurnal variation in pollen vertical distributions in the atmosphere was observed by a surface-based lidar remote sensing technique. Aerosol extinction coefficient and depolarization ratio at 532 nm were obtained from lidar measurements in spring ($4^{th}$ May - $2^{nd}$ June) 2009 at Gwangju Institute of Science & Technology (GIST) located in Gwangju, Korea ($35.15^{\circ}E$, $126.53^{\circ}N$). Unusual variations of depolarization ratio were observed for six days from $4^{th}$ to $9^{th}$ May. Depolarization ratios varied from 0.08 to 0.14 were detected at the low altitude in the morning. The altitude with those high depolarization ratios was increased up to 1.5 - 2.0 km at the time interval between 12:00 and 14:00 LT and then decreased. The temporal variations in high values of depolarization ratios from lidar measurements show good agreement in patterns with the sampled pollen concentrations measured using the Burkard trap sampler. This study demonstrates that the pollen distribution data obtained by lidar measurements can be a useful tool for investigating spatial and temporal characteristic of pollen particles.

• Journal of Korean Society of Forest Science
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• v.63 no.1
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• pp.21-27
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• 1984

This study was to investigate the diurnal changes of shoot water potentials and the characteristics of xylem conductivity of branch in several conifers. The results obtained are as follows: 1) The diurnal shoot water potentials fluctuated with the sunlight intensities, and increase in shoot water potential lagged behind two hours as compared with the time of sunlight decrease in tree crown. 2) The shoot water potential reached the daily maximum ai twelve to fourteen o'clock in the afternoon, and the maximum shoot water potentials were -22 bar in Larix leptolepis, -18 bar in Pinus koraiensis, -15 bar in Pinus densiflora, -14 bar in Abies holophylla, and -10 in Pinus rigida. 3) The average gradient of shoot water potential per one meter height (${\varphi}_L/m$) in tree crown was -1.7 bar/m in Pinus koraiensis while that of Larix leptolepis was -2.1 bar/m. 4) The average of relative xylem conductivities (K, $cm^2/hr{\cdot}atm$) in branches was 2878 in Larix leptolepis, 2763 in Pinus rigida, 2652 in Pinus densiflora, and 2113 in Pinus koraiensis.

• Proceedings of the KSRS Conference
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• 2008.03a
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• pp.113-118
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• 2008

본 연구는 Landsat 7 ETM+를 이용한 지열자원 평가 가능성 연구로써, 위성영상의 열적외 밴드에서 추출된 지표온도와 지열자료의 비교를 통해 위성영상이 초기 지열 탐사에 적용 가능한지를 평가하기 위하여 실시하였다. 지열자원 부존 가능성 평가를 위해 경상도지역(114-35)의 여름시기영상(2001년8월24일)과 겨울시기영상(2000년3월14일)사이의 DN(Digital Number) 값을 이용하였으며, 두 시기영상은 시추공 온도자료 및 지형자료와 함께 비교 분석을 실시하였다. 영상에서 지표온도 추출을 위해 1) NASA에서 제공하는 지표온도 산출 경험식 ( T = K $_2$ / ln ( K $_1$ / L $_{\lambda}$ + 1 ) )을 이용한 방법과 2) 기상청에서 제공하는 실제 지표면온도 관측자료(n=7)를 이용해 영상의 화소(Pixel) 값을 계산하여 실측값과 비교하였다. 3월과 8월 모두 Ground Truth 방법에 따라 추정한 지표면 온도값이 실측값과 더 가깝게 나타났고, 특히 3월은 NASA의 경험식을 이용했을 때 보다 실측 지표면 온도에 훨씬 더 가까운 것으로 나타났다. 지표온도의 일변화(Diurnal ${\triangle}$T)는 지표 열물성과 밀접한 관련이 있으므로, 일변화(Diurnal ${\triangle}$T) 보다는 지열의 영향이 더 클 것으로 기대되는 계절변화(Seasonal ${\triangle}$T)를 이용하여 지열 자료와 비교해 보았다. 그 결과, 계절변화(Seasonal ${\triangle}$T)는 고도에 영향을 받으며, 일사량에 의한 차이는 거의 일정하게 나타났다. 위성영상에서 계절변화(Seasonal ${\triangle}$T)와 심도 20m 온도를 비교해 본 결과결정계수(R$^2$)는 0.46으로 낮지만 심도 20m 온도가 높을수록 계절변화(Seasonal ${\triangle}$T)는 작아지는 경향을 보여 지열자원 탐사에 있어 위성영상 적용 가능성을 볼 수 있었다. 이번 연구는 기초단계로서 두 시기 위성영상을 이용하여 초기 지열자원탐사에 가능성만을 연구했지만, 지형과 특히 토지피복(함수량 등)에 의한 영향에 대해 좀 더 심도 있는 연구가 요구된다.

• Journal of Sericultural and Entomological Science
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• no.12
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• pp.5-11
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• 1970

These works were conducted to investigate the differences of assimilatory productivity under various conditions of cultivation in mulberry trees with the punch method based on dry matter production. The results obtained are as follow： 1. The dry matter of mulberry leaves at 150cm to 200cm high in the morning and from 50cm to 100cm high in the afternoon were higher than other conditions. 2. In daily change of assimilatory, the production of the leaves from 150 cm to 200 cm high in the morning and from 50 cm to 100 cm high in tile afternoon were higher than other conditions. 3. The largest amount of leaf dry matter was produced in south outside of mulberry field, next east outside, and others showed on differences. 4. Increased assimilatory production was occured greatly not only east side of mulberry field from 7 A.M to 10 A.M but also south side of mulberry field from 10 A.M to 1 P.M. 5. In comparison of dry matter production of leaves among varieties, Suwon-sang No. 4 showed greatest amount and followed Sipyung, Kaeryangsuban, Rosang in order. In the varietal differences of assimilatory production per day, Suwonsang No. 4 was greatest and followed Kaeryrangsuban, Sipyung, Rosang in order, 6. Both of the rate of increasing leaf dry matter and net assimilation per day were greatest in the one-half cutting plot and some decreased in one-third cutting plot, in non-cutting plot in order.

• Korean Journal of Environmental Biology
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• v.19 no.1
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• pp.43-48
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• 2001

Chlorophyll fluorescence of needles of Korean fir (Abies koreana) plants and environmental factors of their natural habitat were investigated in order to obtain the information for environmental adaptation and conservation of Korean fir plants. The photochemical efficiency of photosystem II, Fv/Fm, of Korean fir needles was significantly low (0.19-0.36) in the winter, whereas it was high (0.8-0.86) in the summer. The Fv/Fm value of the winter was slightly higher at mid-day than at dawn, suggesting that mid-day environmental conditions of the winter were favorable on needles of Korean fir plants. In contrast, the mid-day Fv/Fm value of the summer maintained high (around 0.8). It indicates that mid-day environmental conditions of the summer did not induce photodamage, although it caused a slight decrease in the Fv/Fm values. The non-photochemical fluorescence quenching (NPQ) of Korean fir needles was very low (0-0.01) all through the day in the winter. However, it was high (0.76) at mid-day in the summer. These results suggest that Korean fir plants have a system for the protection of PS II from mid-day environmental stresses of the summer. In the winter, the Fv/Fm values were positively correlated with temperature, light intensity and relative humidity, although NPQ values showed no correlation with any of them. In the summer, the Fv/Fm values were positively correlated with relative humidity but negatively correlated with temperature and light intensity. These results indicate that increase of tempera-ture, light intensity and relative humidity lead to promotion of the photochemical efficiency in the winter and high temperature and light intensity may cause photoinhibition in the summer.

• Journal of Environmental Science International
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• v.25 no.2
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• pp.259-265
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• 2016

We analyzed diurnal variations in the surface air temperature using the high density urban climate observation network of Daegu in summer, 2013. We compared the time elements, which are characterized by the diurnal variation of surface air temperature. The warming and cooling rates in rural areas are faster than in urban areas. It is mainly due to the difference of surface heat capacity. In addition, local wind circulation also affects the discrepancy of thermal spatiotemporal distribution in Daegu. Namely, the valley and mountain breezes affect diurnal variation of horizontal distribution of air temperature. During daytimes, the air(valley breeze) flows up from urban located at lowlands to higher altitudes of rural areas. The temperature of valley breeze rises gradually as it flows from lowland to upland. Hence the difference of air temperature decreases between urban and rural areas. At nighttime, the mountains cool more rapidly than do low-lying areas, so the air(mountain breeze) becomes denser and sinks toward the valleys(lowlands). As the result, the air temperature becomes lower in rural areas than in urban areas.

• The Korean Journal of Ecology
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• v.19 no.5
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• pp.453-463
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• 1996

Diurnal changes of microclimatic conditions and tissue water relations were measured at two sites where Carpinus laxiflora and C. cordata were allopatrically distributed. The microclimatic conditions at a site where C. laxiflora was distributed produced severe water stress condition during summer months. Daily maximum temperature reached $30.4^\circC$ and the highest vapor pressure deficit was 1.31 KPa when 13 rainless days were continued. During this period soil water content decreased to below the field capacity even at a depth of 20 cm and xylem pressure potential also decreased to ­2.04 MPa. However, turgor potential was maintained more than 0.4 MPa. Patterns of stomatal conductance were changed with evaporative demand and soil water availability. On the other hand, microclimatic conditions at a site where C. cordata was distributed were moderate water strees condition compared with those at a site C. laxiflora was distributed. Though soil water content was maintained above field capacity C. cordata showed a remarkable decrease in turgor potential and stomatal conductance throughout the experiment. These results indicate that there is a difference in habitat characteristics between the two species and C. laxiflora is more resistant than C. cordata to water stress.

• Journal of Environmental Science International
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• v.6 no.6
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• pp.613-628
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• 1997

Diurnal variations of air quality due to the characteristic features of local weather phenomena over Kunsan, Taegu, and Pohang are analyzed using various synoptic wand fields and the characteristics of local weather during the period of 1990 to 1992. The air pollutants analyzed are sulfur dioxide($SO2_$), nitrogen dioxide($NO_2$), and oxidants ($0_3$). The synoptic wind fields estimated at over the 850 hPa geopotential height are divided in terms of four wand directions and two wand speed categories for each season. The synoptic weather conditions are also classified Into two categories depending on the 850 hPa cloud amounts. The present study shows that the $SO_2$ concentration over Kunsan, and Taegu was maximum at the two or three hours after sunrise and second primary was three or flour hours after sunset. On the other hand, Its concentration over Kunsan was malnmum at 1900 LST or 2000 LST The $O_3$ concentration over the three cities shows Its mapdmum In the afternoon when the solar radiation is strong. The $NO_2$ concentration over Kansan shows in reverse proportion to the $O_3$ concentration over the Kunsan.