• Korean Journal of Remote Sensing
• /
• v.38 no.5_1
• /
• pp.571-585
• /
• 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.

• Journal of Korea Water Resources Association
• /
• v.55 no.11
• /
• pp.941-953
• /
• 2022

In this study, monthly water use data were collected for 5 years from the 65 local governments included in the Han-river basin and a typical water usage ratios and patterns were calculated. The difference in water shortage was compared by considering the water usage patterns using the water balance and budget analysis model (MODSIM) and data base. As a result, it was confirmed that the change occurred in the range of -3.120% to +4.322% compared to the monthly constant ratio by period. In addition, when applying the patterns in the water balance model, 17 of the 28 middle watershed showed changes in the quantity of water shortage and the domestic and industrial water shortage would decrease about 8.0% during the maximum drought period. If it is applied in conjunction with predictive research on water usage patterns reflecting climate change, social and regional characteristics in the future, it will be possible to establish a more realistic water supply forecasts and a reliable national water resources plan.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.67 no.4
• /
• pp.296-304
• /
• 2022

To maximize the medicinal properties of bellflower root (Platycodi radix), its growth and development according to soil texture were investigated using four types of soil: masato (decomposed granite), soil mix, loamy sand, and sandy loam. Saponin content was measured. With regard to bellflower root growth depending on soil texture, its growth was better in the order of loamy sand > sandy loam > soil mix > masato in the above-ground part, and loamy sand > soil mix > sandy loam > masato in the underground part in the order. The average content of general ingredients were 77.3% water, 2.6% crude fat, 3.2% crude flour, 6.0% crude protein, and 10.9% carbohydrates. With respect to saponin analysis of bellflower roots, the saponin content regarding platycodin D, platycodin D3, polygalacin D, and deapioplatycodin D were higher in the order of 282.4, 104.7, 29.1, 19.1 mg/100 g, respectively. The content of organic matter and phosphoric acid was high in soil mix and sandy loam, and platycodin D3 showed similar levels in all soil types. As a result, the soil mix is considered most suitable in terms of yield and component levels, however, it is the most expensive type. As a replacement, sandy loam was adequate in terms of fresh weight related to yield and highest saponin content.

• Journal of the Society of Disaster Information
• /
• v.19 no.3
• /
• pp.698-709
• /
• 2023

Purpose: In this paper, we would like to analyze the growth rate of existing urban immersion in the downstream during large-scale urban development and the degree of reduction in existing urban immersion in the downstream when small excellent storage facilities are planned in apartment complexes. Method: A large-scale sewage model was built using the SWMM model of the U.S. Environmental Protection Agency, and the impact of flooding in existing downtown areas downstream was analyzed through simulation. The built model included the development zone, the existing downtown area downstream, and the entire river basin that discharges rainwater. Result: As a result of calculating and simulating the minimum excellent reservoir capacity for each apartment block in the study target area, it was found that the immersion of 4,893㎥ based on one hour, 25,815㎥ based on two hours, and 55,528㎥ based on three hours in the downstream urban area. Conclusion: As in this study, large-scale flooding simulation considering the existing downtown area in the downstream shows a significant increase in flooding in the downstream, and if excellent reservoir capacity is planned for each apartment block before development and the construction of excellent reservoirs is recommended.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2023.05a
• /
• pp.148-148
• /
• 2023

산업 고도화로 인하여 복잡하고 다양한 유기물의 사용량이 증가하였으며, 공공수역 내 새로운 오염물질이 유입됨에 따라 생화학적 산소요구량(BOD) 중심의 수질평가에 한계를 나타내었다. 이후 난분해성 물질을 고려한 유기물관리 정책과 총량관리의 필요성이 제기되었고 국내 하천과 호소에서는 총 유기탄소(TOC)를 유기물 관리지표로 설정하였다. 그러나 부영양 하천과 호소에서 TOC는 외부 부하뿐만아니라 식물플랑크톤의 과잉성장에 의해 증가할 수 있는 항목이므로 TOC 관리정책 추진을 위해서는 유기물의 기원에 대한 파악이 필요하다. 한편, 우리나라와 같이 몬순 기후대에 속한 댐 저수지의 경우 강우시 유입하는 탁수에 의해 다량의 유기물과 인이 유입되기도 하지만 식물플랑크톤의 제한요인 중 광량에 많은 영향을 미친다. 식물플랑크톤의 광합성은 수체 내 유기탄소 내부생성에 매우 중요한 요소이나 점 단위의 실험적 방법을 활용한 유기탄소 순환 해석은 저수지의 시·공간적인 변동성을 고려하기에 한계가 있다. 본 연구의 목적은 금강 수계 최대 상수원인 대청호를 대상으로 3차원 수리-수질 모델을 적용하여 유기탄소 성분 별 유입과 유출, 내부생성 및 소멸량을 평가하고 탁수가 저수지에서의 유기탄소 순환에 미치는 영향을 분석하는데 있다. 유기탄소 물질수지 해석을 위해 AEM3D 모델을 사용하였으며 2018년을 대상으로 입력자료를 구축한 후 보정 및 검정을 수행하였다. 모델은 유기탄소를 입자성, 용존성, 그리고 난분해성과 생분해성으로 구분하여 모의하며 유기물질 성상별 실험결과를 이용하여 입력자료를 구축하였으며 유기탄소순환 해석을 위해 4가지의 탄소성분과 조류 세포 내 탄소의 질량 변화율을 계산하였다. 이를 위해 외부 유입·유출부하율, 수체 내 생성(일차생산, 재부상, 퇴적물과 수체 간 확산) 및 소멸률(POC 및 조류 침강, DOC 무기화, 탈질)을 고려하였으며 탁수의 영향을 분석하기 위해 탁수 포함여부 시나리오를 구성하고 유기탄소 생성 및 소멸기작별 변동성을 비교 분석하였다. 모델은 2018년의 물수지를 적절히 재현하였으며 저수지의 수온 및 탁도 성층구조를 잘 재현해내면서 전반적인 수질을 적절하게 모의하였다. 탁수를 고려하였을 시 연간 TOC 부하량 중 내부기원 부하량은 56% 수준이였으나 탁수를 배제한 경우 내부기원 부하량은 82%로 나타났다. 특히, 연평균 Chl-a 농도가 44~48% 차이가 발생하면서 1차생산량이 약 4배가량 증가하였다. 몬순지역에서의 탁수는 체류시간이 긴 성층 저수지에서 식물플랑크톤 성장제어에 큰 영향을 미쳤으며 전반적인 유기탄소 순환을 해석하는데 있어 매우 중요한 인자로 작용하였다.

• Journal of Korean Society of Disaster and Security
• /
• v.15 no.4
• /
• pp.39-46
• /
• 2022

The rainfall characteristics such as heavy rains are changing differently from the past, and uncertainties are also greatly increasing due to climate change. In addition, urban development and population concentration are aggravating flood damage. Since the causes of urban inundation are generally complex, it is very important to establish an appropriate flood prevention plan. Thus, the government in Korea is establishing standards for disaster prevention performance for each local government. Since the concept of the disaster prevention performance target was first presented in 2010, the setting standards have changed several times, but the overall technology, methodology, and procedures have been maintained. Therefore, in this study, studies and technologies related to urban disaster prevention performance were reviewed using the scientometric analysis method to review them. This analysis is a method of identifying trends in the field and deriving new knowledge and information based on data such as papers and literature. In this study, papers related to the disaster prevention performance of the Web of Science for the last 30 years from 1990 to 2021 were collected. Citespace, scientometric software, was used to identify authors, research institutes, countries, and research trends, including citation analysis. As a result of the analysis, consideration factors such as the the concept of asset evaluation were identified when making decisions related to urban disaster prevention performance. In the future, it is expected that prevention performance standards and procedures can be upgraded if the keywords are specified and the review of each technology is conducted.

• Journal of Korean Society of Environmental Engineers
• /
• v.35 no.9
• /
• pp.613-623
• /
• 2013

This study is purposed to evaluate the airborne asbestos concentrations in life environment surroundings in Seoul. In study, we investigated airborne asbestos concentrations in thirteen subway stations, four monitoring networks and each vicinity roadside, six stream surroundings, four tunnels quarterly and we also investigated relationship between the airborne asbestos concentrations and ambient temperature in monitoring networks and time-based airborne asbestos concentration variability for two typical monitoring networks, two subway stations transferred and used by lots of people through Phase Contrast Microscopy (PCM) and Transmission Electron Microscopy (TEM). The airborne asbestos concentrations by PCM for 4 objects of study were less than the detection limit (7 fiber/$mm^2$) in 111 (50%) out of 223 samples. The highest concentration was 0.0130 f/cc. But additional TEM analysis result for samples exceeding the guideline value for indoor air quality (0.01 f/cc) proposed by the Ministry of Environment (Korea), no asbestos was detected. Similarly TEM analysis result for 124 samples, no asbestos was detected. The average airborne asbestos concentrations by PCM in subway stations, monitoring networks, streams and tunnels were $0.0041{\pm}0.0027$ f/cc, $0.0015{\pm}0.0011$ f/cc, $0.0024{\pm}0.0012$ f/cc and $0.0016{\pm}0.0020$ f/cc. All objects of study were satisfied with the guideline value for indoor air quality. The relationship between the airborne asbestos concentrations and ambient temperature in monitoring networks was generally positive correlation (r = 0.660). The higher ambient temperature was and the more transient population was, the airborne asbestos concentrations by time for two subway stations were increased. While the airborne asbestos concentrations for two monitoring networks showed no variation pattern according to time.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.18 no.4
• /
• pp.327-336
• /
• 2016

The Bagan, the central part of Myanmar, is dry zone where the mean annual precipitation is less than 600 mm for the last ten years. Forest in this region has been degraded due to biotic and abiotic disturbances. While there have been various efforts to rehabilitate the degraded area, the information on growth and physiological characteristics of planting species and the impacts of planting trees in the region still lacks. Therefore, this study was conducted to determine the growth and physiological water use efficiency characteristics of five species (Azadirachta indica A. Juss., Acacia catechu Willd., Eucalyptus camaldulensis Dehn., Acacia leucophloea (Roxb.) Willd. and Albizia lebbek (L.) Willd.) which are utilized as rehabilitation species in the dry zone and to identify the impacts of tree planting on microclimate change in dry zone. The growth and the foliar carbon isotope composition of seedlings and the above mentioned five species planted in 2005 were measured. And from February 2015 to January 2016, microclimatic factors air temperature and relative humidity at 60 cm and 2 m above soil, soil temperature, soil water contents and precipitation were measured at every 30-minute interval from the two weather stations installed in the plantation located in Ngalinpoke Mt. Range. One was established in the center of A. indica plantation, and the other was in the barren land fully exposed to the sunlight. Among the five species, A. indica and A. lebbek which showed higher water use efficiency could be recommended as rehabilitation species in dry zone. Planting trees in the dry area was shown to affect the change of microclimate with shading effects, declining temperature of the land surface and aridity of the air, and to contribute to conserving more water in soil by preventing direct evaporation and containing more water with fine roots of trees.

• Korean journal of applied entomology
• /
• v.15 no.3 s.28
• /
• pp.111-126
• /
• 1976

Regional differences in economic importance of the four species of rice leafhoppers, viz., Laodelphax striatellus, Nephotettix cincticeps, Nilaparvata Iugens and Sogatella furcifera, were analyzed and discussed based on population surveys conducted in Suweon and in southern and south-western coastal areas. The economic importance of L. striatellus and N. cincticeps, which are found throughout the year in Korea, seems to be less in middle regions. This is believed due to effective natural control through severe winter climate, cultural practices in rice and barley growing, and natural enemies such as spiders. However, the economic importance of these two species is significantly greater in southern regions with a less severe winter climate, and where cultural practices in rice and barley favour synchronization between the life cycles of insects and the seasonal succession of host plants. with regard to N. lugens and S. furcifera, which cannot overwinter in Korea, initial populations are the result of long distance migration across the East China Sea. Weather elements related to their migration result in more abundant immigrants of these two species in southern than in middle regions. Thus, different policies are needed for the integrated control of rice leafhoppers in middle and southern Korea.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2015.08a
• /
• pp.83-83
• /
• 2015

현재 인류가 직면한 에너지 부문의 큰 난제는 화석연료의 한정된 매장이기도 하지만 그 사용에 따른 환경오염으로 인한 피해들이 더 큰 문제로 대두되고 있다. 그중 지구 온난화의 영향으로 최근 세계에 국지적인 홍수, 가뭄, 태풍등의 기후 불안정으로 피해보는 상황이 가속화 되고 있다. 또한, 북극지방의 해빙으로 해수면 상승이 예상되며 머지않은 시간에 해수면 상승의 직접적인 피해가 인류에게 오리라는 보고가 많이 발표되고 있다. 그런데 우리가 더욱 중요한 것은 지구촌83의 관성이 크기 때문에 지구 온난화 와 해수면 상승이 인류에 큰 피해를 미치기 시작할 때는 이미 돌이킬 수 없는 상황에 진입해버린다는 사실을 간과하고 있는다는 것이다. 그러므로 과학적 분석에 근거하여 피해를 축소하기위한 활동을 실천해야할 시기이다. 특히, 우리나라의 경우 에너지의 97% 이상을 해외에서 수입하고 있으며, 세계에너지 소비 10위, 석유 소비 7위의 열악한 에너지 자원 빈국인 만큼, 중장기적인 관점에서 석유의존도를 개선하고 신재생에너지원을 확보하는 등 대책마련이 시급한 실정이다. 신재생에너지원으로 현재까지 가장 큰 역할을 해왔던 것 중의 하나가 풍력발전기인데, 오늘날 세계 풍력에 의한 발전량은 세계 총 발전량의 2% 미만에 불과하이다. 이러한 풍력 시장에 발맞춰 국내에서도 풍력발전기 개발에 많은 힘을 쏟고 있는데, 2002년부터 750 kW급 풍력발전기가 처음 개발되기 시작하였고, 이후 2 MW급 풍력발전기와 3 MW급 풍력발전기가 개발되었으며, 최근에는 5 MW와 7.5 MW급등 초대형 풍력발전기가 대기업 중심으로 개발 진행되고 있었으나, 2008년 세계 금융위기 이후 세계 경기침체의 영향으로 국내 풍력산업도 적지않은 영향으로 구조조정되어 기존 7~8개 풍력발전기 제조사들이 3개사 이하로 축소되고 있다. 이에 정부 및 전라남도는 해상풍력산업을 침체기를 겪는 조선산업의 대체산업으로 육성하기위해, 정부 주도로 부안 앞바다에 2.5 GW 해상풍력발전단지개발을 준비 중에 있으며, 전라남도는 전남 서해안에 4 GW 해상풍력발전단지 개발을 서두드고 있다. 특히, 전라남도는 국내에서 가장 많은 풍력에너지 포텐셜을 가지고 있으며, 바람의 질 또한 우수하여 이를 지역산업 활성화의 모멘텀으로 가져가기위해 많은 노력을 기울이고 있다. 그 일례로 영광군 백수읍 하사리 바닷가 $4,342m^2$ 부지에 "풍력테스트베드"를 개발하여 국내 풍력발전기 제조사들이 활용하도록 도움을 주고 있다. 종래의 테스트베드는 해외지역을 이용하였는데, 이는 국내에서 개발된 풍력발전기들이 국제인증을 받기위해 바람의 질이 좋은 해외 테스트베드에 설치되어 평가받았으며 고가의 비용이 소모되었다. 제주도에 테스트베드 장소가 있긴 하지만 수용 규모가 작아 풍력발전기 제조사들이 대기할 수 없어 해외로 나가는 실정에 전라남도의 내륙 테스트베드를 개발함으로서 풍력발전기 제조사들에게 큰 도움을 주고 있다. 본 보고에서는 국가 해상풍력 산업발전의 단계별 전략과 전라남도의 해상풍력산업의 방향 그리고 풍력테스트베드의 현황을 소개하고자 한다.