• Title/Summary/Keyword: 대설특성

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Probable annual maximum of daily snowfall using improved probability distribution (개선된 확률밀도함수 적용을 통한 빈도별 적설심 산정)

  • Park, Heeseong;Chung, Gunhui
    • Journal of Korea Water Resources Association
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    • v.53 no.4
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    • pp.259-271
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    • 2020
  • In Korea, snow damage has happened in the region with little snowfalls in history. Also, accidental damage was caused by heavy snow leads and the public interest on heavy snow has been increased. Therefore, policy about the Natural Disaster Reduction Comprehensive Plan has been changed to include the mitigation measures of snow damage. However, since heavy snow damage was not frequent, studies on snowfall have not been conducted on different points. The characteristics of snow data commonly are not the same as the rainfall data. Some southern coastal areas in Korea are snowless during the year. Therefore, a joint probability distribution was suggested to analyze the snow data with many 0s in a previous research and fitness from the joint probability distribution was higher than the conventional methods. In this study, snow frequency analysis was implemented using the joint probability distribution and compared to the design codes. The results were compared to the design codes. The results of this study can be used as the basic data to develop a procedure for the snow frequency analysis in the future.

Analysis of Cloud Properties Related to Yeongdong Heavy Snow Using the MODIS Cloud Product (MODIS 구름 산출물을 이용한 영동대설 관련 구름 특성의 분석)

  • Ahn, Bo-Young;Cho, Kuh-Hee;Lee, Jeong-Soon;Lee, Kyu-Tae;Kwon, Tae-Yong
    • Korean Journal of Remote Sensing
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    • v.23 no.2
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    • pp.71-87
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    • 2007
  • In this study, 14 heavy snow events in Yeongdong area which are local phenomena are analyzed using MODIS cloud products provided from NASA/GSFC. The clouds of Yeongdong area at observed at specific time by MODIS are classified into A, B, C Types, based on the characteristic of cloud properties: cloud top temperature, cloud optical thickness, Effective Particle Radius, and Cloud Particle Phase. The analysis of relations between cloud properties and precipitation amount for each cloud type show that there are statistically significant correlations between Cloud Optical Thickness and precipitation amount for both A and B type and also significant correlation is found between Cloud Top Temperature and precipitation amount for A type. However, for C type there is not any significant correlations between cloud properties and precipitation amount. A-type clouds are mainly lower stratus clouds with small-size droplet, which may be formed under the low level cold advection derived synoptically in the East sea. B-type clouds are developed cumuliform clouds, which are closely related to the low pressure center developing over the East sea. On the other hand, C-type clouds are likely multi-layer clouds, which make satellite observation difficult due to covering of high clouds over low level clouds directly related with Yeongdong heavy snow. It is, therefore, concluded that MODIS cloud products may be useful except the multi-layer clouds for understanding the mechanism of heavy snow and estimating the precipitation amount from satellite data in the case of Yeongdong heavy snow.

The Distribution of Natural Disaster in Mountainous Region of Gangwon-do (강원도 산지지역의 자연재해 분포 특성)

  • Lee, Seung-Ho;Lee, Kyoung-Mi
    • Journal of the Korean Geographical Society
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    • v.43 no.6
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    • pp.843-857
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    • 2008
  • This study analyzed distribution of natural disaster and trend of related climatic elements in mountainous region of Gangwon-do. In mountainous region of Gangwon-do, there have been 27 natural disasters of which heavy rainfall have the leading cause for the last 5 years(16 times in 2003-2007). It has been 9 natural disasters in Jinbu-myeon Pyeongchang-gun, the most frequent area. The mountainous region has been larger natural damage than its surrounding regions and there has been more damage at higher altitudes. While the heavy rainfall have caused damage over the northwest of mountains, most typhoons have damaged southern part of mountains. Most mountainous region suffers from strong wind but damage by snow is small. In mountainous region of Gangwon-do, annual precipitation, intensity of precipitation and heavy rainfall days have been increasing since 2000 and this tendency is significant in its intensity. However, annual snowfall, snowfall days and heavy snowfall days have been clearly decreasing since 2000. In case heavy rainfall accompanies strong wind, the damages are larger in mountainous region of Gangwon-do. Therefore it is important to be prepared for heavy rainfall and strong wind.

Cloud-cell Tracking Analysis using Satellite Image of Extreme Heavy Snowfall in the Yeongdong Region (영동지역의 극한 대설에 대한 위성관측으로부터 구름 추적)

  • Cho, Young-Jun;Kwon, Tae-Yong
    • Korean Journal of Remote Sensing
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    • v.30 no.1
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    • pp.83-107
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    • 2014
  • This study presents spatial characteristics of cloud using satellite image in the extreme heavy snowfall of the Yeongdong region. 3 extreme heavy snowfall events in the Yeongdong region during the recent 12 years (2001 ~ 2012) are selected for which the fresh snow cover exceed 50 cm/day. Spatial characteristics (minimum brightness temperature; Tmin, cloud size, center of cloud-cell) of cloud are analyzed by tracking main cloud-cell related with these events. These characteristics are compared with radar precipitation in the Yeongdong region to investigate relationship between cloud and precipitation. The results are summarized as follows, selected extreme heavy snowfall events are associated with the isolated, well-developed, and small-scale convective cloud which is developing over the Yeongdong region or moving from over East Korea Bay to the Yeongdong region. During the period of main precipitation, cloud-cell Tmin is low ($-40{\sim}-50^{\circ}C$) and cloud area is small (17,000 ~ 40,000 $km^2$). Precipitation area (${\geq}$ 0.5 mm/hr) from radar also shows small and isolated shape (4,000 ~ 8,000 $km^2$). The locations of the cloud and precipitation are similar, but in there centers are located closely to the coast of the Yeongdong region. In all events the extreme heavy snowfall occur in the period a developed cloud-cell was moving into the coastal waters of the Yeongdong. However, it was found that developing stage of cloud and precipitation are not well matched each other in one of 3 events. Water vapor image shows that cloud-cell is developed on the northern edge of the dry(dark) region. Therefore, at the result analyzed from cloud and precipitation, selected extreme heavy snowfall events are associated with small-scale secondary cyclone or vortex, not explosive polar low. Detection and tracking small-scale cloud-cell in the real-time forecasting of the Yeongdong extreme heavy snowfall is important.

Estimating Equipment and vehicle Demands for Snow Removal Tasks by Road Snow Removal Scenarios (도로 제설 시나리오별 소요 제설장비 및 차량 추정에 관한 연구)

  • Kim, Heejae;Kim, Sunyoung;Kim, Geunyoung
    • Journal of the Society of Disaster Information
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    • v.13 no.2
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    • pp.199-212
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    • 2017
  • Rapid roadway snow removal is significantly important due to difficult occurrence estimation of heavy snowfall disasters by global warming and climate change. Local governments of S. Korea have snow removal equipments and vehicles based on past experiences without considering snowfall and roadway characteristics. The objective of this research is to develop the demand estimation procedure for snow removal equipments and vehicles based on regional snowfall and roadway characteristics. This research first classifies regional snowfall characteristics using KMO's ten-year snowfall data. Second, roadway snow removal length is computed for local governments. Real possession data is compared with demand estimation of snow removal equipments & vehicles for each local government with roadway snow removal scenarios. Finally, required demands of snow removal equipments & vehicles are predicted by concerning regional snowfall amount and required snow removal hours. Results from this research are used for developing heavy snowfall disaster management policies for optimal demands and snow removal routes of 229 local governments.

Frequency analysis for annual maximum of daily snow accumulations using conditional joint probability distribution (적설 자료의 빈도해석을 위한 확률밀도함수 개선 연구)

  • Park, Heeseong;Chung, Gunhui
    • Journal of Korea Water Resources Association
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    • v.52 no.9
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    • pp.627-635
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    • 2019
  • In Korea, snow damage has been happened in the region with no snowfalls in history. Also, casual damage was caused by heavy snow. Therefore, policy about the Natural Disaster Reduction Comprehensive Plan has been changed to include the mitigation measures of snow damage. However, since heavy snow damage was not frequent, studies on snowfall have not been conducted in different points. The characteristics of snow data commonly are not same to the rainfall data. For example, some parts of the southern coastal areas are snowless during the year, so there is often no values or zero values among the annual maximum daily snow accumulation. The characteristics of this type of data is similar to the censored data. Indeed, Busan observation sites have more than 36% of no data or zero data. Despite of the different characteristics, the frequency analysis for snow data has been implemented according to the procedures for rainfall data. The frequency analysis could be implemented in both way to include the zero data or exclude the zero data. The fitness of both results would not be high enough to represent the real data shape. Therefore, in this study, a methodology for selecting a probability density function was suggested considering the characteristics of snow data in Korea. A method to select probability density function using conditional joint probability distribution was proposed. As a result, fitness from the proposed method was higher than the conventional methods. This shows that the conventional methods (includes 0 or excludes 0) overestimated snow depth. The results of this study can affect the design standards of buildings and also contribute to the establishment of measures to reduce snow damage.

Regional snows scenario for the support systems Analysis (지역별 제설 시나리오 응원체계 구축연구)

  • Kim, Heejae;Oak, Youngsuk;Kim, Geunyoung
    • Journal of the Society of Disaster Information
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    • v.13 no.2
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    • pp.163-172
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    • 2017
  • Because of abnormal weather, a heavy snow on the Northern latitudes occurs frequently. This has resulted in significant damage and recovery costs. In korea, it has been declared a special disaster area due to heavy snowfall in Gangneung and Pohang 2004, 2005 and 2011, so there was a revision of action instruction for the road snow removal. Although, in our current system, snow removing methodology, regional equipment holdings, and snow responsible interval, respectively, has been classified by the National Highway, near cities and provinces support system not yet prepared. Only, if snow removing is not possible within the region itself, which contained the contents of "support and assistance to military or nearby offices requests". In this thesis, we studied the disaster scenario development according to heavy snow and the response and support system to the features of each regional. For the scenario deduction, we preferentially collected day snowfall and disaster yearbook data to regionals, classified similar pattern and plotted GIS snow map. We also classified heavy snow disaster by region and type and we deduced five-step scenario. The five-step scenario is nationwide(1st-stage), the National Capital region(2nd-stage), the Chungcheong Provinces(3rd-stage), the Kangwon province(4th-stage) and the Ch?l a provinces(5th-stage). Therefore we build near provinces support system according to five-step scenario.

Snowfall and Ocean Conditions Characteristic in the West Sea of Korea in Winter (동계 서해의 해황과 적설 특성)

  • Go, Woo-Jin;Kim, Sang-Woo;Jang, Lee-Hyun;Choi, Yong-Kyu;Yang, Joon-Yong
    • Proceedings of KOSOMES biannual meeting
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    • 2008.05a
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    • pp.185-189
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    • 2008
  • This study was conducted to find out the effects of relationship between ocean conditions and snowfall when cold and dry continental air mass passes through the West Sea of Korea. Route of continental high atmospheric pressure can cause effect on snowfall at the west regions (Inchoen, Gunsan, Mokpo) of the Korean Peninsula. The continental high atmospheric pressure extend from the southern China to western coastal region of the Korean Peninsula during the December, and it extend from the north side of China through Bohai Sea and Yodong Peninsula to central area of the Korean Peninsula during the February. Therefore, more snowfall recorded in Incheon is higher during Feb. than Dec.. whereas Gunsan and Mokpo is the opposite. The heavy snowfall at the western coastal region of Korea was caused by loss of the heat from the ocean to air when it's higher than $100W/m^2$. the heavy snowfall was also observed when the arrangement of continental high atmospheric pressure and low pressure was high at the West and low at the East, which formed a front in West and when the wind blow from the North or North West at the speed of $4\sim8m/sec$. There were not much relation between salinity in the western sea and snowfall in the western coastal region of Korea.

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On the Spot Inspection of Heavy Snow Damage in the Honam District (Dec. 29, 2007$\sim$Jan. 1, 2008) ('07. 12. 29$\sim$'08. 1. 1 대설 피해 특성과 시설물 안전관리방안)

  • Park, Byung-Cheol;Lee, Jung-Han;Park, Min-Kyu
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.509-512
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    • 2008
  • The objectives of the on-the-spot inspection in Honam district are to find out the situation of the damages on facilities and the reason of the damages caused by heavy snow, and to suggest the preventive plan for reducing the damages from the future heavy snow. From the results of the on-the-spot inspection, plastic houses, barns and ginseng cultivation facilities are mainly damaged by heavy snow in the Honam district, and the importance of the future heavy snow preparedness measures is highly recognized in an agricultural district. In this research, 4 kinds of alternative proposals for the heavy snow are suggested.

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