• Title/Summary/Keyword: 미기후 특성

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Statistical Characteristics of Pier-Scour Equations for Scour Depth Calculation (교각세굴심 산정 공식의 통계적 특성)

  • Lee, Ho Jin;Chang, Hyung Joon;Heo, Tae Young
    • Journal of Korean Society of Disaster and Security
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    • v.12 no.3
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    • pp.51-57
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    • 2019
  • In recent years, the occurrence of localized torrential rain has increased due to the increase in heavy rainfall and massive typhoons caused by abnormal weather. As a result, the flow rate of small and medium-sized rivers in Korea is rapidly increasing, affecting the safety of bridges and increasing the risk of scour. However, the domestic bridge construction technology does not reflect the watershed characteristics of domestic rivers because the bridge scour depth calculation formula developed overseas is used to calculate the bridge scour depth. Therefore, this study is a basic study for prevention of bridge damage according to scouring phenomenon, and a comparative analysis was performed between the experimental data measured through hydraulic model test and the scour depth formulas applied in Korea. In addition, the statistical analysis between experimental data and scour depth formula shows that Coleman's (1971) formula estimates the best scour depth. The results of this study are expected to be used to calculate more accurate bridge scour depth in river design and bridge design.

Review of the Study on Mechanical Properties of Rock Under the Polar Climate Condition (극지 암석의 역학적 특성 분석에 관한 연구 동향)

  • Ryu, Sung-Hoon;Song, Jae-Joon
    • Tunnel and Underground Space
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    • v.20 no.4
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    • pp.241-251
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    • 2010
  • The polar region is in the limelight for an academic worth as well as plenty of natural resources. The study on the polar region was reviewed for better understanding of the polar region and its rock properties. The antarctica has a windy and dry climate along with the lowest temperature on the earth. The thermal distribution according to depth in the area was reported: The freezing-thawing process was repeated in shallow depth, and the temperature falls down below zero under the specific depth. There is a great temperature difference between the atmosphere and rock. A research reported for the degree of weathering of the antarctic slope by using Schmidt hammer and Taffoni test. The rock specimens weathered by repeated freezing-thawing process were tested of the shore hardness and uniaxial compressive strength: The rock strength gradually decreased as the freezing-thawing process was repeated. The comprehensive mechanical properties of the polar region rocks and the relationship between the laboratory weathering test result and the real rock property change in the site remain as future research topics.

Spatial Distribution of Precipitation Trends According to Geographical and Topographical Conditions (지리지형적 조건에 따른 강수량 추세 분포)

  • Rim, Chang-Soo
    • Journal of Korea Water Resources Association
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    • v.42 no.5
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    • pp.385-396
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    • 2009
  • The spatial distribution of precipitation trends according to urbanization, geographical and topographical conditions have been studied. In this study, precipitation data from 1973 to 2006 were analyzed for 56 climatological stations including the Seoul metropolis in South Korea. In addition to annual average daily precipitation, monthly average daily precipitation in April, July, October and January were analyzed, considering seasonal effect. The geographical and topographical characteristics of these sites were examined using GIS analysis. Land use status of the study area was also examined to estimate the extent of urbanization. The study results indicate that annual average precipitation increased, and monthly average precipitation in April and October decreased, while those in January and July increased. Considering urbanization effect, annual average precipitation and monthly average precipitation in July increased; however, monthly average precipitation in January, April and October decreased. Furthermore, compared with urbanization rate and proximity to coast, average elevation of study area appeared to be the most close correlation with annual and monthly averages of precipitation trends.

A preliminary spectral library development for detection and classification of toxic chemicals using hyperspectral technique (초분광 기법을 활용한 유해화학물질 감지 및 분류를 위한 분광라이브러리 구축)

  • Gwon, Yeonghwa;Kim, Dongsu;You, Hojun;Kim, Seojun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2019.05a
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    • pp.131-131
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    • 2019
  • 최근 기후변화와 여름철 고온 등으로 인한 녹조현상, 각종 사고로 인한 화학물질 및 유류 유출 등 수질오염과 관련된 사회적 관심이 높아지고 있다. 특히, 화학사고로 인한 유해화학물질 유출은 접촉시 인체에 악영향을 끼치며, 대기 수질 토양을 오염시키고 주변 농작물의 변색이나 괴사를 유발하는 등 발생 시 적절한 조치와 대응이 필요하다. 환경부에서는 유해화학물질 유출사고로 인한 국민건강 및 환경상의 위해를 예방하기 위해 화학물질관리법과 화학물질 등록 및 평가에 관한 법률을 제정하여 유해화학물질을 관리하고 사고에 대응하고 있다. 그러나, 화학사고 발생 시 현장인력에 의존해 공장 인근의 먼지, 악취 등을 감시하거나 화학물질의 유출이 우려되는 곳에 제한적으로 검출센서를 설치해 사고를 감시하고 있으나 미설치 지역에 대한 능동적 탐지가 어렵고, 공간적 분포 탐지가 불가능하여 초동 대응에 한계가 있다. 한편 최근 초분광 영상을 활용하여 물질 고유의 특성을 분석함으로써 토지피복, 식생, 수질 등의 식별에 활용되고 있어 화학물질 감지 가능성도 보여주고 있다. 하지만, 초분광 센서를 활용한 하천의 화학물질 감지를 위한 연구는 아직 미비한 실정이다. 이에 본 연구에서는 우선 유해화학물질의 일종인 황산, 염화티오닐, 톨루엔을 대상으로 지점 분광복사계로 촬영하여 각각의 화학물질이 갖는 분광특성을 수집하여 초분광 영상으로 상호 구분이 가능한 지 확인하고자 하였다. 이상치 검출 및 신뢰도 높은 자료를 구축하기 위해 다회 반복촬영하였으며 반사도의 표준화를 위해 백색판을 동시에 측정하고 이를 정규화하여 분광 라이브러리를 구축한 결과, 대상 화학물질 별 식별이 가능하다는 결과를 도출하였다. 이러한 가능성에 기반하여 추가적인 유해화학물질 분광 라이브러리 데이터베이스를 구축하면, 사고물질의 식별 및 농도를 즉각적으로 확인하고 실시간 모니터링에 적용하여 신속하게 화학사고 발생여부 감지 및 대응에 활용될 것으로 기대한다.

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Analysis of algae bloom characteristics in Andong reservoir based on hyperspectral images (초분광영상 기반 안동호 조류발생 특성 분석 연구)

  • Kim, Gwang Soo;Kyun, Yeong Hwa;Kim, Dong Soo;Kim, Young Do
    • Proceedings of the Korea Water Resources Association Conference
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    • 2021.06a
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    • pp.119-119
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    • 2021
  • 최근 국내에서는 이상기후변화로 인해 수환경 변화가 일어나고 있으며, 이로인해 하천이나 저수지에 조류의 과대성장이 빈번히 발생되고 있다. 조류의 과대성장으로 인해 조류가 생산하는 독성물질, 이취미 물질은 수질을 악화 및 생태계에 큰영향을 미치는 실정이다. 또한, 조류는 하천, 저수지에 넓은 분포로 발생하게 되며, 현재 조류 조사방법은 다양한 계측장비를 통해 조사를 진행하고 있으나, 조류를 직접 채취하여 검경하거나, 보트 또는 조사선에 센서를 부착하여 측정하기 때문에, 점 또는 선단위의 간혈적 조사가 진행된다. 따라 많은 인력과 시간이 소요된다. 국내에선 인력과 시간을 줄이기 위해 최근 위성영상과 드론을 활용한 조류 원격탐사 모니터링에 대한 연구가 많이 진행되고 있다. 본 연구에서는 안동댐 인근 예안교에서 드론과 초분광센서를 이용하여 초분광데이터를 수집 및 조류 맵핑을 진행하였다. 사용된 드론은 DJI사의 RGB드론과 M-600Pro를 사용하였으며, 초분광 센서는 CORNING사의 microHSITM 410 SHARK를 이용하였으며, 파장 400-1000 nm에서 NIR(visNIR)파장을 분석할 수 있다. 드론에 짐벌을 장착하여 초분광센서를 수표면과 평행하게 두고 촬영 및 영상을 수집하였다. 방사보정을 하기위해 영상을 촬영 구간에 방사 보정용 반사천을 두고 동시간에 같이 촬영 하여 방사보정을 진행하였다. 본 연구에서는 초분광센서와 드론을 활용하여 조류 맵핑에 대한 연구를 하기위해 시료를 채취하여 검경결과와 비교분석을 하였으며, 초분광영상 분석을 통해 조류 최적밴드비를 산정하고 조류 맵핑을 진행하여 촬영구간에 대한 2차원 조류 맵핑 제시하여 하천에 적용하고자 한다.

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A Study on the Analysis and Methods to Improve the Management System for Building Energy Database (국가 건물에너지통합관리시스템의 데이터 품질 분석 및 개선방안 연구)

  • Kim, Sung-Min;Yoon, Jong-Don;Kwon, Oh-In;Shin, Sung-Eun
    • Journal of Energy Engineering
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    • v.25 no.1
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    • pp.131-144
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    • 2016
  • Damage occur frequently around the world on climate change and the main cause of greenhouse gas emissions regulation is growing. To this end, the government has built integrated management system for national building energy. The building energy information is total 6.8 million complex. Integrated management system for national building energy database are matched building registers information and energy information of the supply agencies. However, the matching process has its limitations so advanced work is in progress continuously. This study analyzed integrated management system for national building energy database quality and limitations and deduce improvement plan to increase system reliability and availability. The existing database matching average rate is 85.6%. 58.2% of the total non-matching data type has no building information. To ensure the ease of new database matching and the accuracy of the existing database matching, address standarization and building properties system are needed between building information and energy information. Also, The system construction is required to include information on other energy sources like petroleum energy which has high proportion of non-urban areas and small residential areas and renewable energy which has high potential in development and utilization.

The Application and Analysis of Scale Effect on Dynamic Flood Frequency Analysis (동역학적 홍수빈도 모형의 적용 및 해상도 영향 분석)

  • Mun, Jang-Won;Yu, Cheol-Sang;Kim, Jung-Hun
    • Journal of Korea Water Resources Association
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    • v.34 no.1
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    • pp.81-90
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    • 2001
  • A dynamic flood frequency analysis model was proposed for the frequency analysis in ungaged catchment and applied to 6 subbasins in Pyungchang River basin. As the dynamic flood frequency model requires precipitation, rainfall loss system, and runoff analysis, we adopt the rectangular pulse model, the SCS formula, and the geomorphoclimatic IUH(GcIUH) for the application. Input data for the analysis was borrowed from the results of the statistical flood frequency analysis using L-moment method for the same catchment, and then the return period was estimated using the model. This result was also compared with the return period estimated from the statistical analysis. By comparing with the results from two cases, we found the dynamic flood frequency analysis gave higher estimates than those from statistical analysis for the whole subbasins. However, the dynamic flood frequency analysis model has a potential to be used for determining the design flood for small hydraulic structure in ungaged catchment because it uses only physical parameters for flood frequency analysis. And this model can be easily applicable to other watersheds as the scale effect is negligible.

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Ecological Characteristic of Abies koreana Stand Structure of Mt. Jirisan and Mt. Hallasan (지리산과 한라산의 구상나무 임분 구조의 생태적 특성)

  • Song, Ju Hyeon;Han, Sang Hak;Lee, Sang Hun;Yun, Chung Weon
    • Journal of Korean Society of Forest Science
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    • v.110 no.4
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    • pp.590-600
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    • 2021
  • This study compared the stand structure of Abies koreana forests between Mt. Jirisan and Mt. Hallasan by analyzing DBH distribution, stem vitality, crown structure, importance value, species diversity, and DCA. The data were acquired through the national long-term ecological research project conducted by the Ministry of Environment. In the comparison of DBH class distribution, the stem density of A. koreana with DBH < 20 cm was higher in Mt. Hallasan than that in Mt. Jirisan; however, the stem density of A. koreana with DBH > 20 cm was higher in Mt. Jirisan than that in Mt. Hallasan. For A. koreana stem vitality, the ratio of alive standing was higher in Mt. Jirisan (72.0%) than in Mt. Hallasan (60.7%), whereas the ratio of alive leaning was higher in Mt. Hallasan (10.2%) than in Mt. Jirisan (1.1%). A. koreana stand in Mt. Jirisan was a mature stand with four evenly developed and distinct layers, whereas the tree layer in Mt. Hallasan was less than 10 m and the stand had three layers without a subtree layer. Mt. Hallasan's importance value of A. koreana was 39.4% higher than Mt. Jirisan's importance value of 26.6%. The species diversity of the A. koreana community of Mt. Jirisan was 2.52 times higher than that of Mt. Hallasan, which was 1.58. DCA results revealed that the average distance between Mt. Jirisan and Mt. Hallasan was relatively distinguished, and the degree of scattering of species composition of Mt. Jirisan was relatively dense compared with that of Mt. Hallasan.

Study on Activating a Sustainable Carbon-neutral Community through Resident Participation based on the Evaluation of Changwon City's Carbon-neutral Village Project (창원시 탄소중립마을 사업평가를 통한 지속가능한 주민참여형 탄소중립마을 활성화 방안 연구)

  • Yu Mi Jang;Sung Jun Lee
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.3
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    • pp.569-577
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    • 2023
  • This study selected seven carbon-neutral villages, considering the characteristics of each region, including all five administrative districts of Changwon City, and proposed activation plans based on business evaluations through surveys of local residents and FGIs with leaders. The analysis showed that carbon-neutral education was the most important factor for activating carbon-neutral villages, with a response rate of 91.9% for 17 multiple-choice questions, followed by legal (ordinance) arrangements at 79.3% and village organization building at 74.1%. Based on this, the following activation plans through the participation of residents who are involved in the project of creating a carbon-neutral village in Changwon City were proposed. First, the characteristics of each carbon-neutral village model were classified into a resource circulation-based model, an environmental creation-based model, an environmental education and experience event-based model, and an energy efficiency-based model. Second, it is necessary to create and present carbon-neutral village growth stage guidelines for the growth of carbon-neutral villages. Third, manuals and teaching materials related to carbon neutrality, such as theories, issues, and practices, need to be produced and distributed for leaders and activists to easily apply and access for self-government operation of the village. Finally, if a carbon-neutral support center that is legally installable in Changwon City is established, it is expected that the lives of local residents will become more sustainable for carbon-neutral living in preparation for climate crises.

Topographic and Meteorological Characteristics of Pinus densiflora Dieback Areas in Sogwang-Ri, Uljin (울진 소광리 산림유전자원보호구역 내 금강소나무 고사지역의 지형 환경 특성 분석)

  • Kim, Jaebeom;Kim, Eun-Sook;Lim, Jong-Hwan
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.19 no.1
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    • pp.10-18
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    • 2017
  • Korean Red Pine (Pinus densiflora) has been protected and used as the most ecologically and socio-culturally important tree species in Korea. However, as dieback of Korean red pines has occurred in the protected area of the forest genetic resources. The aims of this study is to identify causes for dieback of pine tree by investigating topographical characteristics of pine tree dieback and its correlation to meteorological factors. We extracted the dead trees from the time series aerial images and analyzed geomorphological characteristics of dead tree concentration area. As a result, 1,956 dead pine trees were extracted in the study region of 2,600 ha. Dieback of pine trees was found mostly in the areas with high altitude, high solar radiation, low topographic wetness index, south and south-west slopes, ridgelines, and high wind exposure compared to other living pine forest area. These areas are classified as high temperature and high drought stress regions due to micro-climatic characteristics affected by topographic factors. As high temperature and drought stress are generally increasing with climate change, we can evaluated that a risk of pine tree dieback is also increasing. Based on these geomorphological characteristics, we developed a pine tree dieback risk map using Maximum Entropy Model (MaxEnt), and it can be useful for establishing Korean red pine protection and management strategies.