• Title/Summary/Keyword: Natural change

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Assessment of Stand-alone Utilization of Sentinel-1 SAR for High Resolution Soil Moisture Retrieval Using Machine Learning (기계학습 기반 고해상도 토양수분 복원을 위한 Sentinel-1 SAR의 자립형 활용성 평가)

  • Jeong, Jaehwan;Cho, Seongkeun;Jeon, Hyunho;Lee, Seulchan;Choi, Minha
    • Korean Journal of Remote Sensing
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    • v.38 no.5_1
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    • pp.571-585
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    • 2022
  • As the threat of natural disasters such as droughts, floods, forest fires, and landslides increases due to climate change, social demand for high-resolution soil moisture retrieval, such as Synthetic Aperture Radar (SAR), is also increasing. However, the domestic environment has a high proportion of mountainous topography, making it challenging to retrieve soil moisture from SAR data. This study evaluated the usability of Sentinel-1 SAR, which is applied with the Artificial Neural Network (ANN) technique, to retrieve soil moisture. It was confirmed that the backscattering coefficient obtained from Sentinel-1 significantly correlated with soil moisture behavior, and the possibility of stand-alone use to correct vegetation effects without using auxiliary data observed from other satellites or observatories. However, there was a large difference in the characteristics of each site and topographic group. In particular, when the model learned on the mountain and at flat land cross-applied, the soil moisture could not be properly simulated. In addition, when the number of learning points was increased to solve this problem, the soil moisture retrieval model was smoothed. As a result, the overall correlation coefficient of all sites improved, but errors at individual sites gradually increased. Therefore, systematic research must be conducted in order to widely apply high-resolution SAR soil moisture data. It is expected that it can be effectively used in various fields if the scope of learning sites and application targets are specifically limited.

Stand Characteristics and NVOCs Emission Characteristics in Warm Temperate Evergreen Broadleaf Forests and Pinus thunbergii Forest (난대 상록활엽수림과 곰솔림 임분 특성 및 NVOCs 발산 특성)

  • Kim, Gwang-Il;Kim, Sang-Mi;Park, In-Teak;Lee, Kye-Han;Oh, Deuk-Sil
    • Korean Journal of Environment and Ecology
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    • v.36 no.4
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    • pp.402-412
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    • 2022
  • This study investigated each forest's stand characteristics and the NVOCs emission characteristics for Quercus acuta, Castanopsis sieboldii, Dendropanax trifidus, Camellia Japonica which are major warm temperate evergreen broad-leaved species, and Pinus thunbergii. Data were collected from May 2019 to January 2020. The seasonal temperature and humidity of each research site indicated the typical climatic characteristics of Korea, which are hot and humid in summer and cold and dry in winter. Also, the atmospheric pressure was generally high in winter and higher in autumn and winter than in spring and summer. Overall, the total volume of NVOCs (Natural Volatile Organic Compounds) from the five research sites was the highest in the summer. The concentration of TNVOCs was relatively high in the Dendropanax trifidus forest in spring and winter, the Castanopsis sieboldii forest in the autumn, and the Quercus acuta forest in the summer. According to the results of this study, it was confirmed that the concentrations of NVOCs emission of warm temperate evergreen broad-leaved species such as Quercus acuta, Castanopsis sieboldii, Dendropanax trifidus and Camellia Japonica were not lower but rather higher than Pinus thunbergii. The correlation was positive (+) between NVOCs emission and temperature (r=0.590, P=0.000) or humidity (r=0.655, P=0.000), whereas it was negative (-) between NVOCs emission and atmospheric pressure (r=-0.384, P=0.000) or wind speed (r=-0.263, P=0.018). Among the micrometeological factors, humidity (β=0.507, P=0.000) was found to have the greatest effect on NVOC emission, followed by temperature, atmospheric pressure, and wind speed.

Remote Sensing and GIS for Earth & Environmental Disasters: The Current and Future in Monitoring, Assessment, and Management 2 (원격탐사와 GIS를 이용한 지구환경재해 관측과 관리 기술 현황 2)

  • Yang, Minjune;Kim, Jae-Jin;Ryu, Jong-Sik;Han, Kyung-soo;Kim, Jinsoo
    • Korean Journal of Remote Sensing
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    • v.38 no.5_3
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    • pp.811-818
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    • 2022
  • Recently, the number of natural and environmental disasters is rapidly increasing due to extreme weather caused by climate change, and the scale of economic losses and damage to human life is increasing accordingly. In addition, with urbanization and industrialization, the characteristics and scale of extreme weather appearance are becoming more complex and large in different ways from the past, and need for remote sensing and artificial intelligence technology for responding and managing global environmental disasters. This special issue investigates environmental disaster observation and management research using remote sensing and artificial intelligence technology, and introduces the results of disaster-related studies such as drought, flood, air pollution, and marine pollution, etc. in South Korea performed by the i-SEED (School of Integrated Science for Sustainable Earth and Environmental Disaster at Pukyong National University). In this special issue, we expect that the results can contribute to the development of monitoring and management technologies that may prevent environmental disasters and reduce damage in advance.

The Perceptions of Non-scientific College Students about the Future Global Environment (미래의 지구 환경에 대한 비과학 전공 대학생들의 인식)

  • Cheong, Cheol;Kim, Yunji
    • Journal of the Korean Society of Earth Science Education
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    • v.14 no.1
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    • pp.21-32
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    • 2021
  • The recognition for future global environment was studied targeting the university students who will be grown as general public composing our society in this study. The rate recognizing as the complex space of natural objects and artifacts is very low for non-science majored university students. Also, the rate recognizing global environment change from now to the future as negative. The environment recognition should be changed as that the university students can imagine the human live together with the nature in the image of future global environment. The environment education find out and practice the method that human can co-exist together to the direction of co-exist with the nature. Also, the rate internalizing future global environment as the space the human amends for non-science majored university students. This result is interpreted as shown the point of view that the global environment can be improved by the human activity, and it suggests the direction of environment education the university should supply. The environment education direction should be converted from the eduction of environment or the eduction from environment to the education for environment. The opportunity for global environment education should be provided to all university students without the discrimination on the major in the university education course. Sustainable global environment eduction is necessary for our son and daughter live on the earth continuously.

Analytical Method of Multi-Preservatives in Cosmetics using High Performance Liquid Chromatography (HPLC 를 이용한 화장품 중 살균보존제 다성분 동시분석법 연구)

  • Min-Jeong, Lee;Seong-Soo, Kim;Yun-Jeong, Lee;Byeong-Chul, Lee
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.48 no.4
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    • pp.321-330
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    • 2022
  • This study attempted to establish an optimal multi-compound simultaneous analysis method that can secure reliable results for 15 - preservatives, 2 - sun screens and 1 - antioxidants of cosmetics using HPLC-PDA. Since the potential of hydrogen (pH) in the mobile phase affects the acid dissociation constant (pKa) of the preservatives, and the peak retention time shift and area change were observed. The peak separation condition was established by adjusting the pH to 0.1% H3PO4 addition (mL) when preparing the mobile phase. As a results of method validation, the linearity correlation coefficient (R2) of above 0.999 were obtained, and accuracy 87.9 ~ 101.1%, 0.1 ~ 7.6% precision for two types of cosmetics (cream and shampoo). It was found that the limit of detection (LOD) was 0.1 ~ 0.2 mg/kg and the limit of quantitation (LOQ) was 2.0 ~ 4.0 mg/kg. In addition, it was possible to simultaneously separate p-anisic acid, a natural compound that was difficult to separate in HPLC due to the small difference from methylparaben, a synthetic preservatives. Through this study, it will be effectively used to secure quality control and safety for compound that need restrictions on use cosmetics.

Analysis on the Changes in Abandoned Paddy Wetlands as a Carbon Absorption Sources and Topographic Hydrological Environment (탄소흡수원으로서의 묵논습지 변화와 지형수문 환경 분석)

  • Miok, Park;Sungwon, Hong;Bonhak, Koo
    • Land and Housing Review
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    • v.14 no.1
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    • pp.83-97
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    • 2023
  • The study aims to provide an academic basis for the preservation and restoration of abandoned paddy wetland and the enhancement of its carbon accumulation function. First, the temporal change of the wetlands was analysed, and a typological classification system for wetlands was attempted with the goal of carbon reduction. The types of wetland were classified based on three variables: hydrological environment, vegetation, and carbon accumulation, with a special attention on the function of carbon accumulation. The types of abandoned paddy wetlands were classified into 12 categories based on hydrologic variables- either high or low levels of water inflow potential-, vegetation variables with either dominance of aquatic plants or terrestrial plants, and three carbon accumulation variables including organic matter production, soil organic carbon accumulation, and decomposition. It was found that the development period of abandoned paddy analyzed with aerial photographs provided by the National Geographic Information Institute happened between 2010 and 2015. In the case of the wetland in Daejeon 1 (DJMN01) farming stopped by 1990 and it appeared to be a similar structure to natural wetlands after 2010 . Over the past 40 years the abandoned paddy wetland changed to a high proportion of forests and agricultural lands. As time went by, such forests and agricultural lands tended to decrease rapidly and the lands were covered by artificial grass and other types of forests.

Predicting Habitat Suitability of Carnivorous Alert Alien Freshwater Fish (포식성 유입주의 어류에 대한 서식처 적합도 평가)

  • Taeyong, Shim;Zhonghyun, Kim;Jinho, Jung
    • Ecology and Resilient Infrastructure
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    • v.10 no.1
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    • pp.11-19
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    • 2023
  • Alien species are known to threaten regional biodiversity globally, which has increased global interest regarding introduction of alien species. The Ministry of Environment of Korea designated species that have not yet been introduced into the country with potential threat as alert alien species to prevent damage to the ecosystem. In this study, potential habitats of Esox lucius and Maccullochella peelii, which are predatory and designated as alert alien fish, were predicted on a national basis. Habitat suitability was evaluated using EHSM (Ecological Habitat Suitability Model), and water temperature data were input to calculate Physiological Habitat Suitability (PHS). The prediction results have shown that PHS of the two fishes were mainly controlled by heat or cold stress, which resulted in biased habitat distribution. E. lucius was predicted to prefer the basins at high latitudes (Han and Geum River), while M. peelii preferred metropolitan areas. Through these differences, it was expected that the invasion pattern of each alien fish can be different due to thermal preference. Further studies are required to enhance the model's predictive power, and future predictions under climate change scenarios are required to aid establishing sustainable management plans.

Distribution of mushrooms spontaneously growing in Naejangsan National Park (내장산국립공원의 자생버섯 분포상)

  • Pyung-Yeol, Ko;Hye-Sung, Park;Seung-Hak, Lee;Yong-Chull, Jeun
    • Journal of Mushroom
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    • v.20 no.4
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    • pp.208-217
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    • 2022
  • Mushrooms in Naejangsan National Park between May and September of 2021 have been surveyed. In this period, a total of 4 divisions, 9 classes, 25 orders, 72 families, 171 genera, and 381 species, including 3 climate-sensitive biological indicator species were found. The order in which the most diverse array of species was observed is Agaricales, which includes 24 families, 64 genera, and 170 species. Among these, the genus Russula was dominant, with 30 species, followed by the genus Amanita with 27 species. Among the 12 grids we investigated, species diversity was greatest in grid F5, in which 56 species of mushrooms were found. In particular, a large number of ectomycorrhizal mushrooms, including Russula spp. and Lactarius spp. were recognized. We presume that the gentle slopes and the low occurrence of Sasa borealis in this area may create a favorable environment for wild mushrooms. In corroboration, some grids (e.g. F6, F8, and F10) covering steep slopes and harboring large numbers of Sasa borealis contained only 19 species. Based on DNA sequence analysis, the NJ21064 was identified as Chlorophyllum hortense, which is newly recorded in Korea.

Predicting the amount of water shortage during dry seasons using deep neural network with data from RCP scenarios (RCP 시나리오와 다층신경망 모형을 활용한 가뭄시 물부족량 예측)

  • Jang, Ock Jae;Moon, Young Il
    • Journal of Korea Water Resources Association
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    • v.55 no.2
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    • pp.121-133
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    • 2022
  • The drought resulting from insufficient rainfall compared to the amount in an ordinary year can significantly impact a broad area at the same time. Another feature of this disaster is hard to recognize its onset and disappearance. Therefore, a reliable and fast way of predicting both the suffering area and the amount of water shortage from the upcoming drought is a key issue to develop a countermeasure of the disaster. However, the available drought scenarios are about 50 events that have been observed in the past. Due to the limited number of events, it is difficult to predict the water shortage in a case where the pattern of a natural disaster is different from the one in the past. To overcome the limitation, in this study, we applied the four RCP climate change scenarios to the water balance model and the annual amount of water shortage from 360 drought events was estimated. In the following chapter, the deep neural network model was trained with the SPEI values from the RCP scenarios and the amount of water shortage as the input and output, respectively. The trained model in each sub-basin enables us to easily and reliably predict the water shortage with the SPEI values in the past and the predicted meteorological conditions in the upcoming season. It can be helpful for decision-makers to respond to future droughts before their onset.

A study on calculation of permeable area ratio in impervious basin using K-LIDM model (K-LIDM 모형을 이용한 불투수유역 내 투수면적비 산정에 관한 연구)

  • Park, Jaerock;Kim, Jaemoon;Baek, Jongseok;Seo, Youngjae;Shin, Hyunsuk
    • Journal of Korea Water Resources Association
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    • v.55 no.11
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    • pp.969-977
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    • 2022
  • In order to respond to the increase in water disasters due to climate change and urbanization, research on low impact development (LID) techniques and application to cities are expanding. The LID technique is a technology that reduces rainwater runoff in the city, controls various water disasters such as flash floods, etc. in an eco-friendly way, and restores the urban water circulation system to a natural water circulation system. However, quantitative analysis of stormwater runoff reduction through the LID technique is insufficient. Therefore, this study analyzed the ratio of the permeable area required to reduce the surface runoff of rainfall (25 mm/hr, 50 mm/hr, 100 mm/hr) with respect to the impervious watershed area of the old city using the permeable pavement. As a result of the analysis, it was found that a permeable area ratio of 7.14 to 12.63% of the total area was required for 25 mm/hr, 15.79 to 26.97% for 50 mm/hr, and 30 to 55.81% for 100 mm/hr.