• Fisheries and Aquatic Sciences
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• v.24 no.1
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• pp.41-52
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• 2021

Data for fish species composition and the catch of fish species were obtained from the daily trading records for the period between April and December 2016 to 2018 at the set net fishing grounds in Yeosu Bay, Korea. The annual mean total catch was 195.8 tons, and the dominant species was the Spanish mackerel (Scomberomorus niphonius), which accounts for about 55 percent of the total catch. The catch increased in spring and autumn. Increase in spring is caused by not Spanish mackerel but other fish while the increase in autumn by Spanish mackerel. The distinct increase of the catch in summer, 2017 was due to the new recruitment of small-sized Spanish mackerel, which was probably to be from the fish population hatched in spring in the East China Sea. Our results showed a strong correlation between water temperature and catch fluctuation. The catch increases with the increase in water temperatures, and the periodic pattern of the water temperature and catch fluctuation is more consistent in the offshore waters, in which warm current flows, than in the coast waters.

• Korean Journal of Agricultural Science
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• v.38 no.1
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• pp.129-143
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• 2011

In this study, to select the incoming solar radiation equation which is most suitable for the estimation of Penman evaporation, 12 incoming solar radiation equations were selected. The Penman evaporation rates were estimated using 12 selected incoming solar radiation equations, and the estimated Penman evaporation rates were compared with measured pan evaporation rates. The monthly average daily meteorological data measured from 17 meteorological stations (춘천, 강능, 서울, 인천, 수원, 서산, 청주, 대전, 추풍령, 포항, 대구, 전주, 광주, 부산, 목포, 제주, 진주) were used for this study. To evaluate the reliability of estimated evaporation rates, mean absolute bias error(MABE), root mean square error(RMSE), mean percentage error(MPE) and Nash-Sutcliffe equation were applied. The study results indicate that to estimate pan evaporation using Penman evaporation equation, incoming solar radiation equation using meteorological data such as precipitation, minimum air temperature, sunshine duration, possible duration of sunshine, and extraterrestrial radiation are most suitable for 11 study stations out of 17 study stations.

• Journal of Environmental Impact Assessment
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• v.14 no.4
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• pp.157-164
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• 2005

Existing models that predict of Daily water supply include statistical models and neural network model. The neural network model was more effective than the statistical models. Only neural network model, which predict of Daily water supply, is focused on estimation of the operational control. Neural network model takes long learning time and gets into local minimum. This study proposes Neuro Genetic hybrid model which a combination of genetic algorithm and neural network. Hybrid model makes up for neural network's shortcomings. In this study, the amount of supply, the mean temperature and the population of the area supplied with water are use for neural network's learning patterns for prediction. RMSE(Root Mean Square Error) is used for a MOE(Measure Of Effectiveness). The comparison of the two models showed that the predicting capability of Hybrid model is more effective than that of neural network model. The proposed hybrid model is able to predict of Daily water, thus it can apply real time estimation of operational control of water works and water drain pipes. Proposed models include accidental cases such as a suspension of water supply. The maximum error rate between the estimation of the model and the actual measurement was 11.81% and the average error was lower than 1.76%. The model is expected to be a real-time estimation of the operational control of water works and water/drain pipes.

• Fisheries and Aquatic Sciences
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• v.19 no.10
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• pp.44.1-44.8
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• 2016

Rockfish, Sebastes schlegelii (mean length $14.53{\pm}1.14cm$ and mean weight $38.36{\pm}3.45g$), were exposed for 4 weeks with the different levels of ammonia in the concentrations of 0, 0.1, 0.5, and 1.0 mg/L at 19 and $24^{\circ}C$. The indicators of growth performance such as daily length gain, daily weight gain, condition factor, and hematosomatic index were significantly reduced by the ammonia exposure and high temperature. The ammonia exposure induced a significant decrease in hematological parameters, such as red blood cell (RBC) count, white blood cell (WBC) count, hemoglobin (Hb), and hematocrit (Ht), whose trend was more remarkable at $24^{\circ}C$. Mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) were also notably decreased by the ammonia exposure. Blood ammonia concentration was considerably increased by the ammonia concentration exposure. In the serum components, the glucose, glutamic oxalate transaminase (GOT), and glutamic pyruvate transaminase (GPT) were substantially increased by the ammonia exposure, whereas total protein was significantly decreased. But, the calcium and magnesium were not considerably changed.

• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.3
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• pp.110-119
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• 2017

The agroclimatic indices are produced by statistical analysis based on primary climate data (e.g., temperature, precipitation, and solar irradiance) or driving agronomic models. This study was carried out to evaluate how selection of daily temperature for a climate normal (1983-2012) affected the precision of the agroclimatic indices. As a first step, averaged daily 0600 and 1500 LST temperature for a climate normal were produced by geospatial schemes based on topo-climatology ($365days{\times}1$ set, EST normal year). For comparison, 30 years daily temperature data were generated by applying the same process ($365days{\times}30sets$), and calculated mean of daily temperature (OBS normal year). The flowering date of apple 'Fuji' cultivar, the last frost date, and the risk of late frost were estimated based on EST normal year data and compared with the results from OBS normal year. The results on flowering date showed 2.9 days of error on average. The last frost date was of 11.4 days of error on average, which was relatively large. Additionally, the risk of the late frost was determined by the difference between the flowering and the last frost date. When it was determined based on the temperature of EST normal year, Akyang was classified as a risk area because the results showed that the last frost date would be the same or later than the flowering date in the 12.5% of area. However, the temperature of OBS normal year indicated that the area did not have the risk of a late frost. The results of this study implied that it would be necessary to reduce the error by replacing the EST method with the OBS method in the future.

• Journal of People, Plants, and Environment
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• v.24 no.5
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• pp.519-527
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• 2021

Background and objective: This study was conducted to establish a Plant Hardiness Zone (PHZ) map, investigate the effect of global warming on changes in PHZ, and elucidate the difference in the distribution of evergreen trees between the central and southern region within hardiness Zone 7b in Korea. Methods: Mean annual extreme minimum temperature (EMT) and related temperature fluctuation data for 40 years (1981 to 2020) in each of the meteorological observation points were extracted from the Open MET Data Portal of the Korea Meteorological Administration. Using EMT data from 60 meteorological observation points, PHZs were classified according to temperature range in the USDA Plant Hardiness Zone Map. Changes in PHZs for each decade related to the effects of global warming were analyzed. Temperature fluctuation before and after the day of EMT were analyzed for 4 areas of Seoul, Suwon, Suncheon, and Jinju falling under Zone 7b. For statistical analysis, descriptive statistics and ANOVA were performed using the IBM SPSS 22 Statistics software package. Results: Plant hardiness zones in Korea ranged from 6a to 9b. Over four decades, changes to warmer PHZ occurred in 10 areas, especially in colder ones. Based on the analysis of daily temperature fluctuation, the duration of sub-zero temperatures was at least 2 days in Seoul and Suwon, while daily maximum temperatures were above zero in Suncheon and Jinju before and after EMT day. Conclusion: It was found that the duration of sub-zero temperatures in a given area is an important factor affecting the distribution of evergreen trees in PHZ 7b.

• Journal of Environmental Science International
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• v.12 no.7
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• pp.697-704
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• 2003

Through data analysis using the meteorological data during 40 years(1961∼2000) for 2 stations(Daegu and Chupungnyong), we studied the present condition and long-term trends in urban climatic environments of Daegu. It was found that there was about 1.5$^{\circ}C$ rise in annual mean temperature of Daegu from 1961 to 2000. On the other hand, that of Chupungnyung was not more than 0.4$^{\circ}C$ for the same period. The regional disparity in temperature changes has been caused by the difference of urban effects on climate between two regions. In particular, the urban warming appears more significant in winter season. There was about 3$^{\circ}C$ rise in annual mean daily minimum temperature of winter season(Dec.∼Feb.) in Daegu. As the result, the number of winter days continuously decreased from 115 days(1961) to 75 days(2000). The long-term trends of relative humidity were also studied to exame the effects of urbanization on climate in Daegu. It was found that there was about 7% decrease in relative humidity of Daegu during past 40 years(1961∼2000). On the other side, the decrease of Chupungnyung was not more than 2% for the same period. The long-term trends of the other climatic factors(fog days, tropical night days, etc) were also studied in this study.

• Korean Journal of Remote Sensing
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• v.20 no.1
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• pp.1-11
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• 2004

Based on surface energy balance climatology, surface temperatures should respond to drying conditions well before plant response. To test this hypothesis, land surface temperatures (LST) derived from MODIS data were analyzed to determine how the data were correlated with climatic water balance variables and NDVI anomalies during a growing season in Western and Central Kansas. Daily MODIS data were integrated into weekly composites so that each composite data set included the maximum temperature recorded at each pixel during each composite period. Time-integrated, or cumulative values of the LST deviation standardized with mean air temperatures had significantly high correlation coefficients with SM, AE/PE, and MD/PE, ranging from 0.65 to 0.89. The Standardized Thermal Index (STI) is proposed in this study to accomplish the objective. The STI, based on surface temperatures standardized with observed mean air temperatures, had significant temporal relationships with the hydroclimatological factors. STI classes in all the composite periods also had a strong correlation with NDVI declines during a drought episode. Results showed that, based on LST, air temperature observations, and water budget analysis, NDVI declines below normal could be predicted as early as 8 weeks in advance in this study area.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.477-482
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• 2014

Variation of anthocyanin contents were analyzed by different growing environments, three locations over three years with 3 black colored soybeans. Anthocyanin contents were different according to growing location, genotypes and planting time, so it can be concluded that anthocyanin content was effected by environmental and genetic variation. Planting date seemed to have a much greater influence on anthocyanin content than cultivar and location. Among different planting dates, anthocyanin contents increased in the seeds planted on June 15 rather than did May 30 and May 15. Compared with 3 cultivars and 3 locations, Ilpumgeomjungkong and Yeonchun had higher contents such as 11.58 mg/ and 9.85 mg/g, respectively. The correlations between color index and anthocyanin content were analyzed by Hunter'value. L (lightness) and b (yellowness) values were correlated negatively with D3G, C3G, Pt3G and total anthocyanin content while a (redness) value was correlated positively. The correlations between meteorological factors and anthocyanin content were analyzed. Anthocyanin content was correlated negatively with mean temperature and accumulated temperature whereas mean daily temperature difference showed positive correlation. We could conclude that the area in which mean temperature was low and daily temperature difference was high is good for attempts to improve black soybean seed quality by the increase of anthocyanin contents.

• Journal of the Korean earth science society
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• v.23 no.5
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• pp.424-435
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• 2002

This study analyzes the surface ozone and meteorological data in Daegu for a period from 1997 to 1999. It also investigates the meteorological characteristics of high ozone episodes. For this study the high ozone episode has been defined as a daily maximum ozone concentration higher than 100ppb in at least one station among six air quality monitoring stations in Daegu, Korea. The frequency of episodes is 13 days. The frequency is the highest in May and September. The average value of daily maximum ozone concentration is 81.6ppb, and 8-hour average ozone concentration is 58.6ppb for the high episodes. This shows that ozone pollution is continuous and wide-ranging in Daegu. The daily maximum ozone concentration is positively correlated to solar radiation and daily maximum temperature, but negatively correlated to relative humidity, wind speed and cloud amount. The maximal correlation coefficient to solar radiation is 0.45. The differences between high ozone episode day's daily mean meteorological value and monthly mean value are +1.58hPa for sea level pressure, +3.45${\circ}$C for maximum temperature, -5.69% for relative humidity, -0.46ms$^{-1}$ for wind speed, -1.79 for cloud amount, and +3.97MJm$^{-2}$ for solar radiation, respectively. This shows that strong solar radiation, low wind speed and no precipitation between 0700${\sim}$1100LST are favorite conditions for high ozone episodes. It is related to the morning stagnant condition.