• 한국물환경학회지
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• 제30권3호
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• pp.329-339
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• 2014

This study aims to estimate chlorophyll-a concentration in rivers using multi-spectral RapidEye imagery and Spectral Mixture Analysis (SMA) and assess the applicability of SMA for multi-temporal imagery analysis. Comparison between images (acquired on Oct. and Nov., 2013) predicted and ground reference chlorophyll-a concentration showed significant performance statistically with determination coefficients of 0.49 and 0.51, respectively. Two band (Red-RE) model for the October and November 2013 RapidEye images showed low performance with coefficient of determinations ($R^2$) of 0.26 and 0.16, respectively. Also Three band (Red-RE-NIR) model showed different performance with $R^2$ of 0.016 and 0.304, respectively. SMA derived Chlorophyll-a concentrations showed relatively higher accuracy than band ratio models based values. SMA was the most appropriate method to calculate Chlorophyll-a concentration using images which were acquired on period of low Chlorophyll-a concentrations. The results of SMA for multi-temporal imagery showed low performance because of the spatio-temporal variation of each end members. This approach provides the potential of providing a cost effective method of monitoring river water quality and management using multi-spectral imagery. In addition, the calculated Chlorophyll-a concentrations using multi-spectral RapidEye imagery can be applied to water quality modeling, enhancing the predicting accuracy.

• Ocean and Polar Research
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• 제30권3호
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• pp.289-301
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• 2008

Community structure of heterotrophic protists and their grazing impact on phytoplankton were studied in Northwest Pacific Ocean during October, 2007. The study area was divided into four regions based on physical properties (temperature and salinity) and chlorophyll-a distribution. They were Region I of North Equatorial Currents, Region II of Kuroshio waters, Region III of shelf mixed water, and Region IV of Tsushima warm current from East China Sea. The distribution of chlorophyll-a concentrations and community structure of heterotrophic protists were significantly affected by physical properties of the water column. The lowest concentration of chlorophyll-a was identified in Region I and II, where pico-sized chlorophyll-a was most dominant (>80% of total chlorophyll-a). Biomass of heterotrophic protists was also low in Region I and II. However, Region III was characterized by low salinity and temperature and high chlorophyll-a concentration, with relatively lower pico-sized chlorophyll-a dominance. The Highest biomass of heterotrophic protists appeared in Region III, along with the relatively less important nanoprotists. In Region I, II and IV, heterotrophic dinoflagellates were dominant among the protists, while ciliates were dominant in Region III. Community structure varied with physical(salinity and temperature) and biological (chlorophyll-a) properties. Biomass of heterotrophic protists correlated well with chlorophyll-a concentration in the study area ($r^2=0.66$, p<0.0001). The potential effect of grazing activity on phytoplankton is relatively high in Region I and II. Our result suggest that biomass and size structure of heterotrophic protists might be significantly influenced by phytoplankton size and concentration.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.913-916
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• 2006

Spatial distribution, seasonal and interannual variability of chlorophyll a concentration in Okhotsk Sea from SeaWiFS data between 2001 and 2004 were describe. An Empirical Orthogonal Function method was applied for analysis data. The ten modes described about 85% of total variance. Two maxima were defined - more intensive in spring and weaker in autumn. The first mode showed zones with chlorophyll a concentration during maximum bloom. The second mode specified timing of spring bloom in various regions in Okhotsk Sea. Analysis of SeaWiFS data indicated connection between highest chlorophyll a concentration and sea surface temperature limits during spring bloom. Similar relation was not found during fall bloom.

• 대한공간정보학회지
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• 제4권2호
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• pp.35-45
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• 1996

호수의 수질관리시 가장 중요한 수질인자 중의 하나인 클로로필의 반사도를 측정하여 가시광선과 근적외선 영역에서 클로로필의 파장별 반사특성을 파악하였고, 클로로필 반사도 스펙트럼에 TM데이터를 적용시켜 TM데이터만으로 클로로필 농도를 추정할 수 있는 변환식을 유도하였다. 또한 1995년 6월 20일과 1996년 3월 18일자의 LANDSAT TM데이터와 위성 통과시간에 대청호에서 측정한 클로로필의 상관관계로부터 회귀모델을 유도하여 대청호 전역의 영양상태 분포도를 작성하였고 계절에 따른 영양상태를 평가하였다.

• 한국토양비료학회지
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• 제31권1호
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• pp.56-60
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• 1998

크롬에 의한 무와 배추 유식물의 생리학적 반응을 조사하기 위하여 수경재배 조건하에서 크롬용액의 농도에 따른 무와 배추종자의 발아율 세포신장, ${\alpha}$-amylase활성도, 엽록소, 단백질함량의 차이를 비교하였다. 크롬처리농도가 증가함에 따라 농도의존적으로 무와 배추종자의 발아율, 세포신장, ${\alpha}$-amylase 활성도가 감소하였는데 배추에서 보다 무에서 그 저해정도가 심하게 나타났다. 무와 배추에서 크롬처리시 약간의 chlorophyll 함량 감소가 있었으며 chlorophyll a가 b보다 더 저해를 받았다. 크롬농도 증가에 따른 ${\alpha}$-amylase 활성도, chlorophyll a와 b, 단백질함량과의 관계를 다중회귀분석한 결과 단백질> ${\alpha}$-amylase>chlorophyll a>chlorophyll b의 순서로 저해를 받았다.

• 한국물환경학회지
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• 제35권1호
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• pp.1-8
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• 2019

The purpose of this study is to evaluate the nutritional status of Lake Jinyang using Landsat 8 satellite image band correlated with chlorophyll-a, which is also related to algae proliferation. We selected 20 Landsat 8 images dating from 2013 to 2017, taken close to water quality measurement date when the cloud cover was less than 20 %. Based on the results of the previous studies, analyzing the correlation between chlorophyll-a, and Landsat 8 satellite image band, we selected near infrared wavelength, band 5 which is closely related to the population of algae. The nutritional status was classified using the Aizaki trophic state index (TSIm). The results of the regression equation between band 5 and the observed chlorophyll-a data was used to calculate chlorophyll-a for the image data from 2013 to 2017. The concentration of chlorophyll-a ranged from 3 to $16.1mg/m^3$. To illustrate the spatial distribution of chlorophyll-a within the lake, the chlorophyll-a concentration was divided into five grades. The images on October 14, 2014 and April 10, 2016 showed relatively high value of chlorophyll-a, while January 18, 2015 and December 6, 2016 chlorophyll-a value were below 5. The images on October 14, 2014 and April 10, 2016 were rated as eutrophic status in most areas. The results of simulating water quality for the day when the water quality was not measured resulted to an approximate value for the Panmun station while the Naedong station needed some corrections.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.487-490
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• 2006

Ocean Color Monitor (OCM) onboard the Indian Remote Sensing Satellite IRS-P4 has been used to retrieve chlorophyll concentration in the Bay of Bengal and the Arabian Sea using a bio-optical algorithm. Cloud masking and atmospheric corrections have been performed before applying mapping function to derive chlorophyll concentration from IRS-P4 OCM data. We have retrieved chlorophyll concentration from OCM, and MODIS during the summer and winter season along the eastern and western coast of India at every 1 degree latitude at increasing distance (25, 50, 100, 150 and 200km) away from the coast as well as near river mouths for the period 2000-2003. We have also studied spatial and temporal dynamics of monthly MODIS Aqua (for period July 2002-April 2004). The seasonal dynamics of chlorophyll concentration over the Bay of Bengal and the Arabian Sea have been discussed using OCM and MODIS for both the coastal region and the open sea.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1039-1041
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• 2003

Ocean color products derived from remote sensing satellite data are useful for monitoring the sea water quality such as the concentrations of chlorophyll, sediments and dissolved organic matter. Currently, ocean color products derived from MODIS data can be requested from NASA over the internet. However, due to the bandwidth limitation of most users in this region, and the time delay in data delivery, the products cannot be use for near-real time monitoring of sea water chlorophyll. CRISP operates a MODIS data receiving station for environmental monitoring purposes. MODIS data have been routinely received and processed to level 1B. We have adapted the higher level processing algorithms from the Institutional Algorithms provided by NASA to run in a standalone environment. The implemented algorithms include the MODIS ocean color algorithms. Seasonal chlorophyll concentration composite can be compiled for the region. By comparing the near-real time chlorophyll product with the seasonal composite, anomaly in chlorophyll concentration can be detected.

• 한국작물학회지
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• 제47권3호
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• pp.263-267
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• 2002

엽록도(SPAD-502)에 따른 엽록소와 질소농도의 관계를 구명하여 벼 재배기술 개발 및 품종육성의 기초 자료로 활용하고자 2001년 작물 시험장 벼 재배 포장에서 화성벼와 광안벼를 이용하여 실험 한 결과는 다음과 같다. 1. 염록도(SPAD값)는 표준시비량(11kg/10a)에서 이앙 이후부터 출수기까지 화성벼가 광안벼보다 1.2-4.4가 낮았다. 2. 엽록소 a함량과 SPAD값은 품종 구분 없이 정의 상관관계로서 엽록소 a 함량(y)은 SPAD값(x)과 y=0.9582x-6.9078 ($R^2$= 0.4307$^{**}$ )의 관계가 성립되었다. 3. 광안벼와 화성벼 지엽의 엽록소 함량은 유의하게 차이가 인정되었으나 엽록소 b의 함량은 차이가 없었다. 따라서 총엽록소 함량에 대한 엽록소 b의 비율은 유의하게 차이가 있었다. 4. SPAD값과 엽록소 함량의 상관관계는 엽록소 a는 화성벼는 0.616$^{**}$ , 광안벼는 0.536$^{**}$ 으로 두 품종 모두 정의 상관이 인정되었으나, 엽록소 b는 화성벼는 0.298, 광안벼는 0.549$^{**}$ 로 광안벼만이 인정되어 품종에 따른 차이가 있었으며, 전체 엽록소 함량은 화성벼는 0.541$^{**}$ 광안벼는 0.596$^{**}$ 로 정의 상관이 있었다. 5. SPAD 값과 질소농도의 상관관계는 화성벼는 0.608$^{**}$ , 광안벼는 0.685$^{**}$ 로 정의 상관이 인정되었다. 그러나 동일 처리의 시험에서도 품종간 SPAD값과 엽록소함량 및 질소농도의 관계가 다르게 나타나므로 SPAD값을 이용하여 엽록소 함량과 질소농도를 추정하는 것은 한계가 있는 것으로 생각된다.

• 한국수산과학회지
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• 제37권3호
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• pp.215-225
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• 2004

Biomass and community composition of microphytobenthos in the Saemankeum tidal flat were studied by HPLC analysis of the photosynthetic pigments from November 2001 to November 2002. The environmental factors of sediment were also investigated to examine the relationship between microphytobenthos biomass and sedimentary environments. The detected photosynthetic pigments of microphytobenthos were chlorophyll a, b, c, fucoxanthin, 19'-hexanoyloxyfucoxanthin, violaxanthin, diadinoxanthin, alloxanthin, diatoxanthin, zeaxanthin+lutein, peridinin and beta-carotene. Pheophytin a, the degradation product of chlorophyll a, was also detected. The results of pigmen analysis suggest the presence of diatom (fucoxanthin), euglenophytes (chlorophyll b), chlorophytes (chlorophyll b + lutein), cyanobacteria (zeaxanthin), cryptophytes (alloxanthin), chrysophytes (fucoxanthin + violaxanthin), prymnesiophytes (19'-hexanoyloxyfucoxanthin) and dinoflagellates (peridinin). Chlorophyll a concentration in the top 0.5 cm of sediment was in the range of $0.24\;mg{\cdot}m\^{-2}\;-32.11\;mg{\cdot}m\^{-2}$ in the study area. The increase of chlorophyll a concentration in the spring indicates the occurrence of a microphytobenthic bloom. In the summer, there was a sharp decrease of the chlorophyll a concentration which was probably due to high grazing activity by macrobenthos. The annual mean chlorophyll a concentration in the study area was low compared to that in most of other tidal flat areas probably due to active resuspension of microphytobenthos and high grazing activity by macrobenthos. There was no clear relationship between microphytobenthos biomass and sedimentary environments because of a large variety of physical, chemical and biological factors, Pigment analysis indicated that while diatoms were dominated in the microphytobenthic community of the Geojon tidal flat, euglenophytes and/or chlorophytes coexisted with diatoms in the Mangyung River tidal flat.