• Title/Summary/Keyword: Climate outlook

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Outlook for Temporal Variation of Trend Embedded in Extreme Rainfall Time Series (극치강우자료의 경향성에 대한 시간적 변동 전망)

  • Seo, Lynn;Choi, Min-Ha;Kim, Tae-Woong
    • Journal of Wetlands Research
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    • v.12 no.2
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    • pp.13-23
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    • 2010
  • According to recent researches on climate change, the global warming is obvious to increase rainfall intensity. Damage caused by extreme hydrologic events due to global change is steadily getting bigger and bigger. Recently, frequently occurring heavy rainfalls surely affect the trend of rainfall observations. Probability precipitation estimation method used in designing and planning hydrological resources assumes that rainfall data is stationary. The stationary probability precipitation estimation method could be very weak to abnormal rainfalls occurred by climate change, because stationary probability precipitation estimation method cannot reflect increasing trend of rainfall intensity. This study analyzed temporal variation of trend in rainfall time series at 51 stations which are not significant for statistical trend tests. After modeling rainfall time series with maintaining observed statistical characteristics, this study also estimated whether rainfall data is significant for the statistical trend test in near future. It was found that 13 stations among sample stations will have trend within 10 years. The results indicate that non-stationary probability precipitation estimation method must be applied to sufficiently consider increase trend of rainfall.

A Drought Outlook Study Using Climate Information in Korea (국내 기상정보를 이용한 가뭄전망기법 연구)

  • Kim, Young-Oh;Lee, Jae-Kyoung;Ko, Yang-Soo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2009.05a
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    • pp.1590-1596
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    • 2009
  • 최근 기후변화의 영향으로 인한 기상이변으로 인해 세계적으로 많은 피해가 발생하고 있으며, 규모도 점점 커지고 있다. 특히 가뭄에 대한 피해는 더욱 더 심화되는 현상으로 보이고 있다. 본 연구에서는 국내에 적합한 월단위와 주단위 가뭄전망을 제시하였다. 월단위 전망에서는 앙상블 기법을 기반으로 기상청에서 제공하는 월간산업기상정보의 적용에 따른 가뭄전망 정확성을 비교하였다. 주단위 전망에서는 기상청에서 제공하는 GDAPS를 이용하여 확정론적 가뭄전망을 하였다. 가뭄지수로서는 강수, 유량, 지하수위를 인자로 하는 MSWSI(Modified Surface Water Supply Index)를 가뭄지수로 사용하였으며, MSWSI는 5개 구간으로 나누었다. 월단위 가뭄전망에서는 물수지모형인 abcd모형에 과거 강수와 잠재증발산량 시나리오를 입력변수로 하여 최종적으로 유량과 지하수위 시나리오를 생산하여, 확률 가뭄전망을 위해 각 구간의 발생확률을 산정하고 실측자료로부터 산정한 MSWSI와 비교하였다. 정확성 평가를 위해서 RPS(Ranked Probability Score)를 이용하였다. 금강유역에 적용한 결과, 이수기(10월-이듬해 6월)에는 4개 달이 초보전망보다 높았으나 전체 RPS는 1.87로서 초보전망의 1.84보다 높아 현재 월단위 가뭄전망기법에는 많은 불확실성이 존재하였다. 또한 월간산업기상정보를 이용한 월단위 가뭄전망에서도 초보전망보다 정확성이 낮아, 현재 중장기 기상정보를 이용하기에는 어려운 것으로 나타났다. 주단위 가뭄전망에서는 abcd모형에 GDAPS를 입력변수로 하여 확정론적 MSWSI를 산정하여 실측자료로부터 산정한 MSWSI와 비교하였으며, Hit ratio를 이용하여 그 정확성을 평가하였다. 주단위 가뭄전망 결과, 주단위 가뭄전망의 Hit ratio가 0.480으로서 초보전망보다 높아 주단위 가뭄전망은 효용성이 있음을 입증하였다. 본 연구에서 적용기간이 짧아 가뭄전망의 정확성을 판단하기는 이르나, 월단위 가뭄전망에서는 기상정보의 정확성이 향상에 따라 가뭄전망의 정확성도 향상될 것으로 판단된다. 장기적으로 본 연구 결과를 토대로 단기와 중장기 가뭄전망을 수행하고 평가한다면, 가뭄전망에 대한 신뢰도가 더 높아질 것으로 사료된다.

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Development and Evaluation of Drought Outlook method Using Climate Prediction with Bayesian method (기후예측정보와 베이지안 기법을 활용한 가뭄전망기술 개발 및 평가)

  • Son, Kyung-Hwan;Bae, Deg-Hyo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2015.05a
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    • pp.22-22
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    • 2015
  • 가뭄은 적시에 경보해야 하는 홍수와 달리 진행속도가 느리고 시간적으로 대처할 여유가 있어 진행중일지라도 미리 감지만 한다면 그 피해를 최소화할 수 있다. 이로 인해 미국 등 수문기상 선진국에서는 수문기상 장기예보자료로부터 가뭄전망정보 생산기술을 개발하였으며, 특히 가뭄전망의 정확도 향상을 위해 여러 통계적 보정기법을 적용하고 있다. 국내의 경우 기상청에서 가뭄전망을 목적으로 2011년에 수치예보모델을 이용하여 가뭄전망정보를 생산한바 있으나, 전망정보의 불확실성 문제로 가뭄예보에 활용하는데 한계가 있어 이를 개선할 수 있는 기술개발이 요구되는 실정이다. 본 연구에서는 기후예측자료를 이용하여 가뭄전망정보 생산기술을 개발하고 정확도 개선을 위해 베이지안 기법을 연계하였다. GloSea5 (Global Seasonal forecast model 5) 장기예보자료를 이용하였으며, 베이지안 기법을 통해 과거 관측자료에 대한 사전분포, 모델의 전망정보로부터 우도함수를 유도하여 최종 사후분포를 추정하였다. 베이지안 기법 적용 전 후에 따른 가뭄지수를 산정하였다. 관측자료 기반의 가뭄지수와의 비교분석을 통해 선행기간 및 계절별 가뭄예측 성능을 평가하였으며, 실제 가뭄기간 동안에 가뭄의 재현성을 지역별로 분석하였다. 장기예보자료만을 활용한 기존 가뭄전망에서는 관측 자료가 포함된 1개월 전망에서도 불확실성이 매우 높았지만 베이지안 기법 적용으로 가뭄전망의 정확도가 크게 개선되었다. 특히, 1, 2개월 전망의 시계열 가뭄지수가 관측기반의 가뭄지수의 거동과 매우 유사하게 나타났으며, 지역별로도 베이지안 기법 적용시 실제 가뭄피해 상황을 적절히 재현하는 것으로 나타났다. 국내 가뭄예보에 있어 기후예측정보를 단순활용하기 보다는 베이지안과 같은 통계적 보정기법을 이용하여 가뭄전망정보를 생산하는 것이 바람직하며, 본 연구에서는 가뭄예보업무에 활용될 수 있도록 베이지안 기법에 대한 검증 및 평가를 지속적으로 수행할 계획이다.

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A Study on derivation of drought severity-duration-frequency curve through a non-stationary frequency analysis (비정상성 가뭄빈도 해석 기법에 따른 가뭄 심도-지속기간-재현기간 곡선 유도에 관한 연구)

  • Jeong, Minsu;Park, Seo-Yeon;Jang, Ho-Won;Lee, Joo-Heon
    • Journal of Korea Water Resources Association
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    • v.53 no.2
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    • pp.107-119
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    • 2020
  • This study analyzed past drought characteristics based on the observed rainfall data and performed a long-term outlook for future extreme droughts using Representative Concentration Pathways 8.5 (RCP 8.5) climate change scenarios. Standardized Precipitation Index (SPI) used duration of 1, 3, 6, 9 and 12 months, a meteorological drought index, was applied for quantitative drought analysis. A single long-term time series was constructed by combining daily rainfall observation data and RCP scenario. The constructed data was used as SPI input factors for each different duration. For the analysis of meteorological drought observed relatively long-term since 1954 in Korea, 12 rainfall stations were selected and applied 10 general circulation models (GCM) at the same point. In order to analyze drought characteristics according to climate change, trend analysis and clustering were performed. For non-stationary frequency analysis using sampling technique, we adopted the technique DEMC that combines Bayesian-based differential evolution ("DE") and Markov chain Monte Carlo ("MCMC"). A non-stationary drought frequency analysis was used to derive Severity-Duration-Frequency (SDF) curves for the 12 locations. A quantitative outlook for future droughts was carried out by deriving SDF curves with long-term hydrologic data assuming non-stationarity, and by quantitatively identifying potential drought risks. As a result of performing cluster analysis to identify the spatial characteristics, it was analyzed that there is a high risk of drought in the future in Jeonju, Gwangju, Yeosun, Mokpo, and Chupyeongryeong except Jeju corresponding to Zone 1-2, 2, and 3-2. They could be efficiently utilized in future drought management policies.

Development of index for flood risk assessment on national scale and future outlook (전국 단위 홍수위험도 평가를 위한 지수 개발과 미래 전망)

  • Kim, Daeho;Kim, Young-Oh;Jee, Hee Won;Kang, Tae-Ho
    • Journal of Korea Water Resources Association
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    • v.53 no.5
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    • pp.323-336
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    • 2020
  • Owing to climate change, the annual precipitation in Korea has increased since the 20th century, and it is projected to continue increasing in the future. This trend of increasing precipitation will raise the possibility of floods; hence, it is necessary to establish national adaptation plans for floods, based on a reasonable flood risk assessment. Therefore, this study focuses on developing a framework that can assess the flood risk across the country, as well as computing the flood risk index (FRI). The framework, which is based on IPCC AR5, is established as a combination of three indicators: hazard, exposure, and capacity. A data-based approach was used, and the weights of each component were assigned to improve the validity of the FRI. A Spearman correlation analysis between the FRI and flood damage verified that the index was capable of assessing potential flood damage. When predicting scenarios for future assessment using the HadGEM3-RA based on RCP 4.5 and 8.5, the flood risk tends to be lower in the early and mid-21st century, and it becomes higher at the end of the 21st century as compared with the present.

The costume culture of China is as old and varied as her long history (중국 소수민족의 복식 연구(1))

  • 박춘순
    • Journal of the Korean Society of Costume
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    • v.26
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    • pp.175-206
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    • 1995
  • The costume culture of China is as old and varied as her long history. As China is a multiracial nation and consists of fifty-six min-ority races including Han race, there are not only fifty-six different costumes in China but each races' costume habit is very different. Therefore, Chinese penninsula can be considered an enor-mous exhibition center of the costumes. This study undertook on the assumption that the costumes' mainstream of Korea and east-northern Asia as well as that of China could be examined by investigating the minority races' costumes in the east-and west-northern areas of China. The process of evolution of the costume of a particular people, country or area is subject not only to constraints related to geography such as climate, topography or local products but is also affected by numorous environmental influences including cultural, economic, social and even pol-itical ones in terms of the selection of material, styling, color and standard of tailoring. In other words, things like philosophy of life, religious be-lief, aesthetic outlook, moral code, class system, degree of affluence, and cultural exchange will all be reflected directly or indirectly by features of a people's or country's style costume. Of course, there are several factors affecting to the style of costume of the minority people in China. However, the only three factors-geo-graphical and environmental, production method, and religious belef-will be touched in this study. First of all, the geograghical and eenviron-mental factor would be the decisive one because the costume should be designed to overcome the constraints of climate and geographical environ-ments. Accordingly, each race has an unique style of costume. The costume of the minority races in the northern parts are loose and wide, and made of warm furs. For instance, Mongolian robe has the quality of anti-wind, anti-cold and warmness, and the width of a sleeve is narrow and long. Secondly, the costume style can be said to be limited by the production pattern, when the geo-graphical environment was affected to decide the costume style, the production pattern was together affected to it . In case of Mongolian robe, they should satisfy the dual condition as the practical function. One is the condition that they should be fitted to the climate, and the other is the condition that they should be suit-able to the nomadic life. Mongolian robes are suitable to the nomadic peoples because they are designed for not only overcoming the cold wind and weather but being used as the bedquit at night. The costumes of Hoche people was made of the skin of the fish and wild animals because of their main means of living being fishing and hunting. Accordingly, their costumes are dur-able, warm and water-proof. Finally, the style of the costume is affected by the religious belief. In other words, the pattern in fashion is closely related with the religious be-lief or ancestor worship and nature worship. Ac-cordingly, the symbols of these worship are often emerged in the decoration of the costume. The design of costume of the people in the northern areas of China is very simple. It is related with their monotheism. On the other hand, the costumes of twen쇼 minority races in the east-northern parts of China can be devided into three racial groups such as the long robes of Man people and Mongols, Tunics of the peoples in the west-northern areas, and the pants and jackets of Hoche people. The minorority races all has not only the unique costume habit but their costumes are also related with their living style and production means.

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Geographical Migration of Winter Barley in the Korean Peninsula under the RCP8.5 Projected Climate Condition (신 기후변화시나리오에 따른 한반도 내 겨울보리 재배적지 이동)

  • Kim, Dae-Jun;Kim, Jin-Hee;Roh, Jae-Hwan;Yun, Jin I.
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.14 no.4
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    • pp.161-169
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    • 2012
  • The RCP 8.5 scenario based temperature outlook (12.5 km resolution) was combined with high-definition gridded temperature maps (30 m grid spacing) across the Korean Peninsula in order to reclassify the cold hardiness zone for winter barley, a promising grain crop in the future under warmer winter conditions. Reference maps for the January minimum and mean temperature were prepared by applying the watershed-specific geospatial climate prediction schemes to the synoptic observations from 1981 to 2010 across North and South Korea. Decadal changes in the January minimum and mean temperatures projected by a regional version of RCP8.5 climate change scenario were prepared for the 2011-2100 period at 12.5 km grid spacing and were subsequently added to the reference maps, producing the 30 m resolution temperature surfaces for 9 decades from 2011 to 2100. A criterion for threshold temperature to grow winter barley safely in Korea was applied to the future temperature surfaces and the resulting maps were used to predict the production potential of 3 cultivar groups for the 9 future decades under the projected temperature conditions. By 2020s, hulled barley cultivars could be grown safely at the southern part of North Korea as well as the mountainous Gangwon province. Furthermore, most of South Korean rice paddies will be safe for growing naked barley after harvesting rice. Also, dual cropping systems such as 'winter-barley after rice' could be possible at most of the North Korean rice paddies by 2040s. Additional grain production in North Korea could increase up to 4 million tons per year if dual cropping systems can be fully operated, i.e., winter barley after rice at all lowlands and winter barley after maize or potato at all uplands.

A Study on Status Analysis for Advancement iNto Agricultural Sector in Central Asia (중앙아시아 농업분야 진출을 위한 현황분석 - 우즈베키스탄, 카자흐스탄, 키르기즈스탄 중심으로 -)

  • Park, Dong-Jin;Jo, Sung-Ju;Park, Jeong-Woon;Sa, Soo-Jin;Hong, Jung-Sik;Lee, Dong-Jin
    • Journal of the Korean Society of International Agriculture
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    • v.30 no.4
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    • pp.328-338
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    • 2018
  • Central Asia (Uzbekistan, Kazakhstan, Kyrgyzstan) is a hot and arid continental climate, with most areas (68%) consisting of barren vegetation, desert, and meadows. The main agricultural areas for crop production include irrigated farmland, non-irrigated farmland, grassland, prairie and mountain. We are experiencing climate change with recent climate variability increasing. Agriculture is one of major economic sectors and provides a means of livings for the rural population of Central Asia, especially the poor. In the past two decades, Central Asia has experienced a high population growth rate, with Kazakhstan at 16.8%, Uzbekistan at 34.5% and Kyrgyzstan at 28.4%. As a major industry, Kazakhstan has the largest share of exports of agricultural products followed by petroleum, mineral resources, steel, and chemicals. Uzbekistan is the fifth largest cotton exporter as well as the sixth largest cotton producer in the world. Kyrgyzstan exports ores, stones, cultured pearls, and minerals. These three countries are rich in mineral resources, agricultural products, and energy resources. However, not only do they have difficulties in economic development due to the weakness of logistics and industrial infrastructure, but they also have imperceptible cooperation and investment among countries due to insufficient research and development. Through this study, we will investigate national outlook, economic indicators, major agricultural products, import and export status, and agricultural technology cooperation status, and study how Korean agricultural industry advances into these countries through SWOT analysis. Through this, we hope to contribute to the basic data of Central Asian studies and cooperation and investment in agriculture in each country. In addition, in order to increase cooperative exchange and investment in these countries, we will prepare a Central Asia logistics hub for the rapidly changing interKorean railroad era.

A Feasibility Study of a Field-specific Weather Service for Small-scale Farms in a Topographically Complex Watershed (지형이 복잡한 집수역의 소규모농장에 맞춘 기상서비스의 실현가능성)

  • Yun, Jin I.
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.17 no.4
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    • pp.317-325
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    • 2015
  • An adequate downscaling of synoptic forecasts is a prerequisite for improved agrometeorological service to rural areas in South Korea where complex terrains and small farms are common. In this study, geospatial schemes based on topoclimatology were used to scale down the Korea Meteorological Administration (KMA) temperature forecasts to the local scale (~30 m) across a rural catchment. Then, using these schemes, local temperatures were estimated at 14 validation sites at 0600 and 1500 LST in 2013/2014 and were compared with the observations. The estimation errors were substantially reduced for both 0600 and 1500 LST temperatures when compared against the uncorrected KMA products. The improvement was most notable at low lying locations for the 0600 temperature and at the locations on west- and south-facing slopes for the 1500 LST temperature. Using the downscaled real-time temperature data, a pilot service has started to provide the field-specific weather information tailored to meet the requirements of small-scale farms. For example, the service system makes a daily outlook on the phenology of crop species grown in a given field using the field-specific temperature data. When the temperature forecast is given for next morning, a frost risk index is calculated according to a known relationship of phenology and frost injury. If the calculated index is higher than a pre-defined threshold, a warning is issued and delivered to the grower's cellular phone with relevant countermeasures to help protect crops against frost damage.

Performance Assessment of Two-stream Convolutional Long- and Short-term Memory Model for September Arctic Sea Ice Prediction from 2001 to 2021 (Two-stream Convolutional Long- and Short-term Memory 모델의 2001-2021년 9월 북극 해빙 예측 성능 평가)

  • Chi, Junhwa
    • Korean Journal of Remote Sensing
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    • v.38 no.6_1
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    • pp.1047-1056
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    • 2022
  • Sea ice, frozen sea water, in the Artic is a primary indicator of global warming. Due to its importance to the climate system, shipping-route navigation, and fisheries, Arctic sea ice prediction has gained increased attention in various disciplines. Recent advances in artificial intelligence (AI), motivated by a desire to develop more autonomous and efficient future predictions, have led to the development of new sea ice prediction models as alternatives to conventional numerical and statistical prediction models. This study aims to evaluate the performance of the two-stream convolutional long-and short-term memory (TS-ConvLSTM) AI model, which is designed for learning both global and local characteristics of the Arctic sea ice changes, for the minimum September Arctic sea ice from 2001 to 2021, and to show the possibility for an operational prediction system. Although the TS-ConvLSTM model generally increased the prediction performance as training data increased, predictability for the marginal ice zone, 5-50% concentration, showed a negative trend due to increasing first-year sea ice and warming. Additionally, a comparison of sea ice extent predicted by the TS-ConvLSTM with the median Sea Ice Outlooks (SIOs) submitted to the Sea Ice Prediction Network has been carried out. Unlike the TS-ConvLSTM, the median SIOs did not show notable improvements as time passed (i.e., the amount of training data increased). Although the TS-ConvLSTM model has shown the potential for the operational sea ice prediction system, learning more spatio-temporal patterns in the difficult-to-predict natural environment for the robust prediction system should be considered in future work.