• Title/Summary/Keyword: geo-climate

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Soil Erosion Modeling in the 3S Basin of the Mekong River Basin

  • Thuy, Hoang Thu;Lee, Giha;Yu, Wansik;Shin, Yongchul
    • Journal of the Korean GEO-environmental Society
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    • v.18 no.7
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    • pp.21-35
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    • 2017
  • The 3S Basin is described as an important contributor in terms of many aspects in the Mekong River Basin in Southeast Asia. However, the 3S Basin has been suffering adverse consequences of changing discharge and sediment, which are derived from farming, deforestation, hydropower dam construction, climate change, and soil erosion. Consequently, a large population and ecology system that live along the 3S Basin are seriously affected. Accordingly, the calculating and simulating discharge and sediment become ever more urgent. There are many methods to simulate discharge and sediment. However, most of them are designed only during a single rainfall event and they require many kinds of data. Therefore, this study applied a Catchment-scale Soil Erosion model (C-SEM) to simulate discharge and sediment in the 3S Basin. The simulated results were judged with others references's data and the observed discharge of Strung Treng station, which is located in the mainstream and near the outlet of the 3S Basin. The results revealed that the 3S Basin distributes 31% of the Mekong River Basin's total discharge. In addition, the simulated sediment results at the 3S Basin's outlet also substantiated the importance of the 3S Basin to the Mekong River Basin. Furthermore, the results are also useful for the sustainable management practices in the 3S Basin, where the sediment data is unavailable.

Analysis of Liquefied Layer Activities Considering Erosion and Sedimentation of Debris Flow (토석류의 침식 및 퇴적을 고려한 유동층의 거동 분석)

  • Kim, Sungduk;Lee, Hojin
    • Journal of the Korean GEO-environmental Society
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    • v.20 no.4
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    • pp.23-29
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    • 2019
  • Heavy rainfall is in causing debris flow by recent climate change and causes much damage in the downstream. The debris flow from the mountainous area runs to the downstream, repeating sedimentation and erosion, and appears as a fluidized soil-water mixture. Continuity equation and momentum equation were applied to analyze the debris flow with strong mobility, and the sedimentation and erosion velocity with fine particle fractions were also applied. This study is to analyze the behavior of debris flow at the downstream end for the variation of the amount of sediments can occur in the upstream of the mountain. Analysis of sediment volume concentration at the downstream end of the channel due to the variance of the length of pavement of the granulated soils resulted in the higher the supply flow discharge and the longer the length of pavement, the greater the difference in the level of sediment concentration and the earlier the point of occurrence of the inflection point. The results of this study will provide good information for determining the erosion-sedimentation velocity rate which can detect erosion and sedimentation on steep slopes.

Evaluation of GSICS Correction for COMS/MI Visible Channel Using S-NPP/VIIRS

  • Jin, Donghyun;Lee, Soobong;Lee, Seonyoung;Jung, Daeseong;Sim, Suyoung;Huh, Morang;Han, Kyung-soo
    • Korean Journal of Remote Sensing
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    • v.37 no.1
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    • pp.169-176
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    • 2021
  • The Global Space-based Inter-Calibration System (GSICS) is an international partnership sponsored by World Meteorological Organization (WMO) to continue and improve climate monitoring and to ensure consistent accuracy between observation data from meteorological satellites operating around the world. The objective for GSICS is to inter-calibration from pairs of satellites observations, which includes direct comparison of collocated Geostationary Earth Orbit (GEO)-Low Earth Orbit (LEO) observations. One of the GSICS inter-calibration methods, the Ray-matching technique, is a surrogate approach that uses matched, co-angled and co-located pixels to transfer the calibration from a well calibrated satellite sensor to another sensor. In Korea, the first GEO satellite, Communication Ocean and Meteorological Satellite (COMS), is used to participate in the GSICS program. The National Meteorological Satellite Center (NMSC), which operated COMS/MI, calculated the Radiative Transfer Model (RTM)-based GSICS coefficient coefficients. The L1P reproduced through GSICS correction coefficient showed lower RMSE and Bias than L1B without GSICS correction coefficient applied. The calculation cycles of the GSICS correction coefficients for COMS/MI visible channel are provided annual and diurnal (2, 5, 10, 14-day), but long-term evaluation according to these cycles was not performed. The purpose of this paper is to perform evaluation depending on the annual/diurnal cycles of COMS/MI GSICS correction coefficients based on the ray-matching technique using Suomi-NPP/Visible Infrared Imaging Radiometer Suite (VIIRS) data as reference data. As a result of evaluation, the diurnal cycle had a higher coincidence rate with the reference data than the annual cycle, and the 14-day diurnal cycle was the most suitable for use as the GSICS correction coefficient.

Estimation of non-point pollution reduction effect of Haean Catchment by application of Nature-based Solutions (자연기반해법 적용에 따른 강원도 양구군 해안면의 비점오염 저감 효과 추정)

  • Lee, Ji-Woo;Park, Chan
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.25 no.3
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    • pp.47-62
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    • 2022
  • The Ministry of Environment has been working to reduce the impact on biodiversity, ecosystems, and social costs caused by soil runoff from highland Agricultural fields by setting up non-point pollution source management districts. To reduce soil loss, runoff path reduction technology has been applied, but it has been less cost effective. In addition, non-point pollution sources cause environmental conflicts in downstream areas, and recently highland Agricultural fields are becoming vulnerable to climate change. The Ministry of Environment is promoting the optimal management plan in earnest to convert arable land into forests and grasslands, but since non-point pollution is not a simple environmental problem, it is necessary to approach it from the aspect of NbS(Nature-Based Solution). In this study, a scenario for applying the nature-based solution was established for three subwatersheds west of Haean-myeon, Yanggu-gun, Gangwon-do. The soil loss distribution was spatialized through GeoWEPP and the amount of soil loss was compared for the non-point pollution reduction effect of mixed forests and grasslands. When cultivated land with a slope of 20% or more and ginseng fields were restored to perennial grasslands and mixed forests, non-point pollution reduction effects of about 32% and 29.000 tons compared to the current land use were shown. Also, it was confirmed that mixed forest rather than perennial grassland is an effective nature-based solution to reduce non-point pollution.

Impact Assessment of Sea_Level Rise based on Coastal Vulnerability Index (연안 취약성 지수를 활용한 해수면 상승 영향평가 방안 연구)

  • Lee, Haemi;Kang, Tae soon;Cho, Kwangwoo
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.27 no.5
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    • pp.304-314
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    • 2015
  • We have reviewed the current status of coastal vulnerability index(CVI) to be guided into an appropriate CVI development for Korean coast and applied a methodology into the east coast of Korea to quantify coastal vulnerability by future sea_level rise. The CVIs reviewed includes USGS CVI, sea_level rise CVI, compound CVI, and multi scale CVI. The USGS CVI, expressed into the external forcing of sea_level rise, wave and tide, and adaptive capacity of morphology, erosion and slope, is adopted here for CVI quantification. The range of CVI is 1.826~22.361 with a mean of 7.085 for present condition and increases into 2.887~30.619 with a mean of 12.361 for the year of 2100(1 m sea_level rise). The index "VERY HIGH" is currently 8.57% of the coast and occupies 35.56% in 2100. The pattern of CVI change by sea_level rise is different to different local areas, and Gangneung, Yangyang and Goseong show the highest increase. The land use pattern in the "VERY HIGH" index is dominated by both human system of housing complex, road, cropland, etc, and natural system of sand, wetland, forestry, etc., which suggests existing land utilization should be reframed in the era of climate change. Though CVI approach is highly efficient to deal with a large set of climate scenarios entailed in climate impact assessment due to uncertainties, we also propose three_level assessment for the application of CVI methodology in the site specific adaptation such as first screening assessment by CVI, second scoping assessment by impact model, and final risk quantification with the result of impact model.

The Design of Web-based Crop Information System Using Open-Source Framework and Remotely Sensed Data (오픈 소스 프레임워크와 원격 탐측자료를 이용한 웹 기반 작황 정보 시스템 설계)

  • Nguyen, Minh Hieu;Ma, Jong Won;Lee, Kyungdo;Heo, Joon
    • Korean Journal of Remote Sensing
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    • v.33 no.5_2
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    • pp.751-762
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    • 2017
  • A crop information system can provide information regarding crop distribution, crop growth conditions, crop yield in various forms such as monitoring, forecasting, estimation or analysis. This paper presents the design and construction of a crop information system based on data collected in Korea, USA, and China. Therein, climate data including temperature, precipitation,solar radiation are used to evaluate the impact on crop growth, NDVI (Normalized Difference Vegetation Index) data is used in crop monitoring, and crop map data is utilized for the management of crop distribution. The system has achieved three prominent results: 1) Providing information with high frequency, 2) Automatically creating the report through the analysis of the data, 3) The users to easily approach the system and retrieve the information.

Qualitative Content Analysis of Forest Healing Experience in Forest Life

  • Kang, Hee Won;Lee, Geo Lyong
    • Journal of People, Plants, and Environment
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    • v.24 no.3
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    • pp.301-309
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    • 2021
  • Background and objective: The purpose of this study is to analyze the case of healing experience for lifestyle and environmental diseases through life and activities in the forest from the perspecitive of critical realism, and how the causal power and mechanism of the healing experience relate to forest healing factors and programs. Methods: 93 video data of people who started living in the forest for disease treatment were analyzed using a qualitative content analysis method from the perspective of critical realism. Categories for analysis include general categories (age, duration, occupation, disease name), forest therapy categories (climate therapy, plant therapy, water therapy, diet therapy, kinesiotherapy, psychotherapy), and other categories (ecology, learning and management, life tools), etc., and the unit of analysis is the context unit. Results: 1) The diseases that motivated life in the forest were digestive system diseases, lung diseases, cardiovascular diseases, endocrine system diseases, and various lifestyle-related diseases and environmental diseases in similar proportions. This indicates that forest life does not have specificity to respond to specific diseases, but provides treatment and recovery for all lifestyle and environmental diseases. 2) Among the forest therapies, climate therapy and plant therapy are related to the climatic and residential environment in the forest where 'natural persons' live. And others such as water therapy, diet therapy, kinesiotherapy, psychotherapy indicate the change from the lifestyle that caused the disease to the lifestyle for treatment and recovery. Conclusion: Life and activities in the forest provide an environment for treatment and recovery in which the healing principles such as aromatherapy, nutritional and dietary therapy, kinesiotherapy, and emotional psychotherapy are integrated in the 'real world'.

Wave Tendency Analysis on the Coastal Waters of Korea Using Wave Hind-Casting Modelling (파랑후측모델링을 이용한 연안 파랑경향성 분석)

  • Kang, Tae-Soon;Park, Jong-Jip;Eum, Ho-Sik
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.7
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    • pp.869-875
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    • 2016
  • The purpose of this study is to analyze the long-term wave characteristics and tendencies of coastal waters near Korea based on wave hind-casting modelling. Wave hind-casting modelling was performed with a wind data set from ECMWF (2001~2014), which provides data from 1979 to the present. The results of numerical modelling were verified with observed data collected using wave buoys installed by the Korea Meteorological Administration (KMA) and Korea Hydrographic and Oceanographic Agency (KHOA) in offshore waters. The results agreed well with observations from buoy stations, especially during event periods such as typhoons. The quantitative RMSE value was 0.5 m, which was significant. Consequently, the results of a wave tendency analysis for 14 years (2001~2014) showed an increased appearance ratio for waves of more than 2 m in height at all regional domains. The mean appearance ratio was 0.082 % per year, which implies that coastal waves have been increasing continuously. This coastal wave tendency analysis data can be used to evaluate coastal vulnerability due to recent climate change and the design of coastal erosion prevention structures.

National Disaster Scientific Investigation and Disaster Monitoring using Remote Sensing and Geo-information (원격탐사와 공간정보를 활용한 국가 재난원인 과학조사 및 재난 모니터링)

  • Kim, Seongsam;Kim, Jinyoung;Kim, Jinsoo
    • Korean Journal of Remote Sensing
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    • v.35 no.5_2
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    • pp.763-772
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    • 2019
  • High-resolution satellites capable of observing the Earth periodically enhance applicability of remote sensing in the field of national disaster management from national disaster pre-monitoring to rapid recovery planning. The National Disaster Management Research Institute (NDMI) has been developed various satellite-based disaster management technologies and applied to disaster site operations related to typhoons and storms, droughts, heavy snowfall, ground displacement, heat wave, and heavy rainfall. Although the limitation of timely imaging of satellite is a challenging issue in emergent disaster situation, it can be solved through international cooperation to cope with global disasters led by domestic and international space development agencies and disaster organizations. This article of special issue deals with the scientific disaster management technologies using remote sensing and advanced equipments of NDMI in order to detect and monitor national disasters occurred by global abnormal climate change around the Korean Peninsula: satellite-based disaster monitoring technologies which can detect and monitor disaster in early stage and advanced investigation equipments which can collect high-quality geo-information data at disaster site.

Comparative Analysis of Surface Heat Fluxes in the East Asian Marginal Seas and Its Acquired Combination Data

  • Sim, Jung-Eun;Shin, Hong-Ryeol;Hirose, Naoki
    • Journal of the Korean earth science society
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    • v.39 no.1
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    • pp.1-22
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    • 2018
  • Eight different data sets are examined in order to gain insight into the surface heat flux traits of the East Asian marginal seas. In the case of solar radiation of the East Sea (Japan Sea), Coordinated Ocean-ice Reference Experiments ver. 2 (CORE2) and the Objectively Analyzed Air-Sea Fluxes (OAFlux) are similar to the observed data at meteorological stations. A combination is sought by averaging these as well as the Climate Forecast System Reanalysis (CFSR) and the National Centers for Environmental Prediction (NCEP)-1 data to acquire more accurate surface heat flux for the East Asian marginal seas. According to the Combination Data, the annual averages of net heat flux of the East Sea, Yellow Sea, and East China Sea are -61.84, -22.42, and $-97.54Wm^{-2}$, respectively. The Kuroshio area to the south of Japan and the southern East Sea were found to have the largest upward annual mean net heat flux during winter, at -460- -300 and at $-370--300Wm^{-2}$, respectively. The long-term fluctuation (1984-2004) of the net heat flux shows a trend of increasing transport of heat from the ocean into the atmosphere throughout the study area.