• Title/Summary/Keyword: Natural change

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Estimating Worst Case Flood and Inundation Damages under Climate Change

  • Kim, Sunmin;Tachikawa, Yasuto;Nakakita, Eiichi
    • Proceedings of the Korea Water Resources Association Conference
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    • 2016.05a
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    • pp.189-189
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    • 2016
  • To generate information that contributes to climate change risk management, it is important to perform a precise assessment on the impact in diverse aspects. Considering this academic necessity, Japanese government launched continuous research project for the climate change impact assessment, and one of the representative project is Program for Risk Information on Climate Change (Sousei Program), Theme D; Precise Impact Assessment on Climate Change (FY2012 ~ FY2016). In this research program, quantitative impact assessments have been doing from a variety of perspectives including natural hazards, water resources, and ecosystems and biodiversity. Especially for the natural hazards aspect, a comprehensive impact assessment has been carried out with the worst-case scenario of typhoons, which cause the most serious weather-related damage in Japan, concerning the frequency and scale of the typhoons as well as accompanying disasters by heavy rainfall, strong winds, high tides, high waves, and landslides. In this presentation, a framework of comprehensive impact assessment with the worst-case scenario under the climate change condition is introduced based on a case study of Theme D in Sousei program There are approx. 25 typhoons annually and around 10 of those approach or make landfall in Japan. The number of typhoons may not change increase in the future, but it is known that a small alteration in the path of a typhoon can have an extremely large impact on the amount of rain and wind Japan receives, and as a result, cause immense damage. Specifically, it is important to assess the impact of a complex disaster including precipitation, strong winds, river overflows, and high tide inundation, simulating how different the damage of Isewan Typhoon (T5915) in 1959 would have been if the typhoon had taken a different path, or how powerful or how much damage it would cause if Isewan Typhoon occurs again in the future when the sea surface water temperature has risen due to climate changes (Pseudo global warming experiment). The research group also predict and assess how the frequency of "100-years return period" disasters and worst-case damage will change in the coming century. As a final goal in this research activity, the natural disaster impact assessment will extend not only Japan but also major rivers in Southeast Asia, with a special focus on floods and inundations.

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The Case Study of Bangladesh for International Cooperation on the Vulnerable Region of Natural Hazard (자연재해 증가 지역의 국제협력 지원 방안을 위한 방글라데시 사례 연구)

  • Lee, Jawon
    • Journal of the Korean association of regional geographers
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    • v.19 no.2
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    • pp.340-351
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    • 2013
  • International society has been making a lively discussion about natural disaster by climate change to mitigate natural hazard centering around intra-government association. This study dealt with a strategic mitigation and technical adaptation to support a habitual natural disaster region such as Bangladesh in terms of international cooperation for assistance to protect against the natural hazard. The land-cover on scale of one third of Bangladesh is situated lower than sea level that causes habitual flooding accident which gets increasing in the strengthen every single year. Most of people lives around exterior sea coast being faced with disaster of abnormal storm forming every three year cycle. Especially, the socio-economic status of the people in the coast is usually very low, and it need to get help from international cooperation aid. Therefor, the case study for the vulnerability of natural disaster in Bangladesh on geographical analysis is meaningful to join the international cooperation taking a part of role on technical support and education for adaptation of the natural disaster.

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CHANGE DETECTION ANALYSIS OF FORESTED AREA IN THE TRANSITION ZONE AT HUSTAI NATIONAL PARK, CENTRAL MONGOLIA

  • Bayarsaikhan, Uudus;Boldgiv, Bazartseren;Kim, Kyung-Ryul;Park, Kyeng-Ae
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.426-429
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    • 2007
  • One of the widely used applications of remote sensing studies is environmental change detection and biodiversity conservation. The study area Hustai Mountain is situated in the transition zone between the Siberian taiga forest and Central Mongolian arid steppe. Hustai National Park carries out one of several reintroduction programs of takhi (wild horse or Equus ferus przewalskii) from various zoos in the world and it represents one of a few textbook examples of successful reintroduction of an animal extinct in the wild. In this paper we describe the results of an analysis on the change of remaining forest area over the 7-year period since Hustai Mountain was designated as a protected area for reintroduction to wild horses. Today the forested area covers approximately 5% of the Hustai National Park, mostly the north-facing slopes above 1400 m altitude. Birch (Betula platyphylla) and aspen (Populus tremula) trees are predominant in the forest. We used Landsat ETM+ images from two different years and multi temporal MODIS NDVI data. Land types were determined by supervised classification methods (Maximum Likelihood algorithm) verified with ground-truthing data and the Land Change Modeler (LCM) which was developed by Clark Labs. Forested area was classified into three different land types, namely the forest land, mountain meadow and mountain steppe. The study results illustrate that the remaining birch forest has rapidly changed to fragmented forest land and to open areas. Underlying causes for such a rapid change during the 15-year period may be manifold. However, the responsible factors appear to be the drying off and outbreak of forest pest species (such as gypsy moth or Lymantria dispar) in the area.

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Analysis of Changes in Extreme Weather Events Using Extreme Indices

  • Kim, Byung-Sik;Yoon, Young-Han;Lee, Hyun-Dong
    • Environmental Engineering Research
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    • v.16 no.3
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    • pp.175-183
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    • 2011
  • The climate of the $21^{st}$ century is likely to be significantly different from that of the 20th century because of human-induced climate change. An extreme weather event is defined as a climate phenomenon that has not been observed for the past 30 years and that may have occurred by climate change and climate variability. The abnormal climate change can induce natural disasters such as floods, droughts, typhoons, heavy snow, etc. How will the frequency and intensity of extreme weather events be affected by the global warming change in the $21^{st}$ century? This could be a quite interesting matter of concern to the hydrologists who will forecast the extreme weather events for preventing future natural disasters. In this study, we establish the extreme indices and analyze the trend of extreme weather events using extreme indices estimated from the observed data of 66 stations controlled by the Korea Meteorological Administration (KMA) in Korea. These analyses showed that spatially coherent and statistically significant changes in the extreme events of temperature and rainfall have occurred. Under the global climate change, Korea, unlike in the past, is now being affected by extreme weather events such as heavy rain and abnormal temperatures in addition to changes in climate phenomena.

Development of Mosaic Aerial Photographs for Shoreline Change Study in Nakdong Estuary (낙동강 하구 해안선변화 연구를 위한 모자이크 항공사진의 구축)

  • Kim, Baeck-Oon;Khim, Boo-Keun;Lee, Sang-Ryong
    • Ocean and Polar Research
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    • v.27 no.4
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    • pp.497-507
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    • 2005
  • This paper presents a method for obtaining mosaic aerial photographs that are useful for a long-term shoreline change study in the Nakdong estuary. Although this method involves digital photogrammetry software of the shelf its usage can be simplified to accomodate the shoreline change study. Ground control points, which are common in aerial photographs, were measured from digital maps. Block triangulation was highly affected by land-based GCPs. Extension of tie points near the shoreline to vertical control points gave more reliable results for the block triangulation. A constant Digital Elevation Model (DEM), close to mean sea level, was employed to produce ortho-rectified photographs, from which mosaic photographs were made. Accuracy of photographs were found to be acceptable for the analysis of long-term shoreline change, and the promising construction of a shoreline change database in the Nakdong estuary.

Experimental Study on Natural Period for Arch Structure with Column (하부기둥에 따른 아치구조물의 고유주기 변화에 관한 실험적 연구)

  • Kang, Joo-Won;Seok, Keun-Yung;Lee, Sang-Hoon;Kim, Gee-Cheol
    • Journal of Korean Association for Spatial Structures
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    • v.9 no.2
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    • pp.83-90
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    • 2009
  • The previous studies for dynamic behavior of spatial structure have been zoomed in on roof structure by numerical analytic method. But the roof structure of real spatial structures is supported by lower structure as column and wall. So, when earthquake is occurred, it is predicted that dynamic behavior of roof structure is affected by lower structure. Therefore, on this study, natural period characteristics of arch structures are analyzed according to section, length and the modulus of elasticity of brass column and polycarbonate column and additional mass of roof structure by the scale-down model of arch structure as the most simple structure of spatial structures. The changes of natural periods are generally alike. But, when Polycarbonate column is connected to roof structure, the change of natural period for change of section is relatively large. That means that change of section and section and length of column and additional mass of roof structure have less influence on change of stiffness because the modulus of elasticity of brass is relatively large.

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Can Agricultural Aid and Remittances Alleviate Macroeconomic Volatility in Response to Climate Change Shocks? (아프리카 국가들의 경제성장률 변동성에 기후변화, 송금 및 농업 원조가 미치는 영향 분석)

  • You, Soobin;Kim, Taeyoon
    • Environmental and Resource Economics Review
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    • v.25 no.4
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    • pp.471-494
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    • 2016
  • This study investigates the effect of remittance and agricultural aid inflows on GDP growth rate volatility in response to climate change shocks in twenty-eight African countries by using system generalized method of moments from 1996 to 2013 with three years grouped data. The climate change shocks are indicated by four variables; natural disasters, rainfall variability, fluctuation in temperature and the weighted anomaly standardized precipitation (WASP) index. Consequently, natural disasters and temperature variability have a significant effect on GDP volatility, while rainfall variability and WASP index have no adverse consequence on stabilization of the economy. On the other hand, in general, remittances and agricultural aid are helpful to stabilize the economy and especially remittances inflows can play a crucial role as insurance when natural disasters occur.

Improvement of the Environmental Conservation Value Assessment Map (ECVAM) by Complement of the Vegetation Community Stability Item (식생 군집구조 안정성 평가항목 보완을 통한 국토환경성평가지도 개선방안 연구)

  • Jeon, Seong-Woo;Song, Won-Kyong;Lee, Moung-Jin;Kang, Byung-Jin
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.13 no.2
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    • pp.114-123
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    • 2010
  • The Environmental Conservation Value Assessment Map (ECVAM) is a five grade assessment map created with nationally integrated environmental information and environmental values. The map is made through the evaluation of 67 items, including greenbelt area and bio-diversity. The ECVAM assesses the stability of the community using forest maps. However, the existing assessment method is problematic because the assessment grades are evaluated using higher than practical values; in part because it uses even-valued overlay and minimal indicator methods. This study was performed in order to suggest an integrated assessment method that could complement the stability evaluation based on existing methods. Accordingly, this study added forest type information, including whether the forest was natural or artificial, to the overlay method using forest diameter maps and forest density maps. As a result, the proposed ECVAM indicated a drastic grade change. After applying the method in South Korea, Grade I areas decreased 12.1%, from 52.6% to 40.6%, Grade II areas increased 11.9%, from 17.4% to 29.2%, and Grade III areas increased 0.2%, from 17.1% to 17.4%, respectively. From the results of the field survey, we found differences between natural forest and planted forest with regard to the number of mortality, species of shrubs, and vine cover. This means that natural forests are more stable than planted forests. This study suggests an improved assessment methodology to complement the existing EVCAM method. The results are expected to be used in environmental evaluations and forest conservation value assessments in ecology and environmental fields.

Feedback scope for fault detection and localization

  • Hunsang Jung;Park, Youngjin
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.32.6-32
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    • 2002
  • The damage localization of the structural system using the natural frequency measurement only is proposed. The existing methods use the changes of mode shape, strain mode shape or curvature mode shape before and after the damage occurrence as these shapes carry the geometric information of the structure. Basically, the change of natural frequencies of the structure can be used as the indicator of the damage occurrence but not as the indicator of the damage location as the natural frequency changes does not carry the geometric information of the structure. In this research, the feedback scope method that measures the natural frequency changes of the structure with and without the feedback Ioo...

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