• Title/Summary/Keyword: Spatio-temporal Change

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Quantifying Climate Regulation of Terrestrial Ecosystems Using a Land-Atmosphere Interaction Model Over East Asia for the Last Half Century

  • Hong, Seungbum;Jang, Inyoung;Jeong, Heon-Mo
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.1 no.1
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    • pp.58-67
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    • 2020
  • Terrestrial ecosystems influence climate change via their climate regulation function, which is manifested within the carbon, water, and energy circulation between the atmosphere and surface. However, it has been challenging to quantify the climate regulation of terrestrial ecosystems and identify its regional distribution, which provides useful information for establishing regional climate-mitigation plans as well as facilitates better understanding of the interactions between the climate and land processes. In this study, a land surface model (LSM) that represents the land-atmosphere interactions and plant phenological variations was introduced to assess the contributions of terrestrial ecosystems to atmospheric warming or cooling effects over East Asia over the last half century. Three main climate-regulating components were simulated: net radiation flux, carbon exchange, and moisture flux at the surface. Then, the contribution of each component to the atmospheric warming or cooling (negative or positive feedback to the atmosphere, respectively) was investigated. The results showed that the terrestrial ecosystem over the Siberian region has shown a relatively large increase in positive feedback due to the enhancement of biogeochemical processes, indicating an offset effect to delay global warming. Meanwhile, the Gobi Desert shows different regional variations: increase in positive feedback in its southern part but increase in negative one in its eastern part, which implies the eastward movements of desert areas. As such, even though the LSM has limitations, this model approach to quantify the climate regulation is useful to extract the relevant characteristics in its spatio-temporal variations.

An Analysis of the Effect of Climate Change on Nakdong River Environmental Flow (낙동강 유역 환경유량에 대한 기후변화의 영향 분석)

  • Lee, A Yeon;Kim, Sangdan
    • Journal of Korean Society on Water Environment
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    • v.27 no.3
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    • pp.273-285
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    • 2011
  • This study describes the modeling of climate change impact on runoff across southeast Korea using a conceptual rainfall-runoff model TANK and assesses the results using the concept of environmental flows developed by International Water Management Institute. The future climate time series is obtained by scaling the historical series, informed by 4 global climate models and 3 greenhouse gas emission scenarios, to reflect a $4.0^{\circ}C$ increase at most in average surface air temperature and 31.7% increase at most in annual precipitation, using the spatio-temporal changing factor method that considers changes in the future mean seasonal rainfall and potential evapotranspiration as well as in the daily rainfall distribution. Although the simulation results from different global circulation models and greenhouse emission scenarios indicate different responses in flows to the climate change, the majority of the modeling results show that there will be more runoff in southeast Korea in the future. However, there is substantial uncertainty, with the results ranging from a 5.82% decrease to a 48.15% increase in the mean annual runoff averaged across the study area according to the corresponding climate change scenarios. We then assess the hydrologic perturbations based on the comparison between present and future flow duration curves suggested by IMWI. As a result, the effect of hydrologic perturbation on aquatic ecosystems may be significant at several locations of the Nakdong river main stream in dry season.

Spatio-Temporal Projection of Invasion Using Machine Learning Algorithm-MaxEnt

  • Singye Lhamo;Ugyen Thinley;Ugyen Dorji
    • Journal of Forest and Environmental Science
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    • v.39 no.2
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    • pp.105-117
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    • 2023
  • Climate change and invasive alien plant species (IAPs) are having a significant impact on mountain ecosystems. The combination of climate change and socio-economic development is exacerbating the invasion of IAPs, which are a major threat to biodiversity loss and ecosystem functioning. Species distribution modelling has become an important tool in predicting the invasion or suitability probability under climate change based on occurrence data and environmental variables. MaxEnt modelling was applied to predict the current suitable distribution of most noxious weed A. adenophora (Spreng) R. King and H. Robinson and analysed the changes in distribution with the use of current (year 2000) environmental variables and future (year 2050) climatic scenarios consisting of 3 representative concentration pathways (RCP 2.6, RCP 4.5 and RCP 8.5) in Bhutan. Species occurrence data was collected from the region of interest along the road side using GPS handset. The model performance of both current and future climatic scenario was moderate in performance with mean temperature of wettest quarter being the most important variable that contributed in model fit. The study shows that current climatic condition favours the A. adenophora for its invasion and RCP 2.6 climatic scenario would promote aggression of invasion as compared to RCP 4.5 and RCP 8.5 climatic scenarios. This can lead to characterization of the species as preferring moderate change in climatic conditions to be invasive, while extreme conditions can inhibit its invasiveness. This study can serve as reference point for the conservation and management strategies in control of this species and further research.

Application of SAD Curves in Assessing Climate-change Impacts on Spatio-temporal Characteristics of Extreme Drought Events (극한가뭄의 시공간적 특성에 대한 기후변화의 영향을 평가하기 위한 SAD 곡선의 적용)

  • Kim, Hosung;Park, Jinhyeog;Yoon, Jaeyoung;Kim, Sangdan
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.6B
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    • pp.561-569
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    • 2010
  • In this study, the impact of climate change on extreme drought events is investigated by comparing drought severity-area-duration curves under present and future climate. The depth-area-duration analysis for characterizing an extreme precipitation event provides a basis for analysing drought events when storm depth is replaced by an appropriate measure of drought severity. In our climate-change impact experiments, the future monthly precipitation time series is based on a KMA regional climate model which has a $27km{\times}27km$ spatial resolution, and the drought severity is computed using the standardized precipitation index. As a result, agricultural drought risk is likely to increase especially in short duration, while hydrologic drought risk will greatly increase in all durations. Such results indicate that a climate change vulnerability assessment for present water resources supply system is urgent.

Recent Spatio-temporal Changes of Landscape Structure, Heterogeneity and Diversity of Rural Landscape: Implements for Landscape Conservation and Restoration (한국 농산촌 경관의 구조와 이질성 및 다양성의 최근 변화: 경관의 보전과 복원과의 관계)

  • Hong, Sun-Kee;Rim, Young-Deuk;Nakagoshi, Nobukazu;Chang, Nam-Kee
    • The Korean Journal of Ecology
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    • v.23 no.5
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    • pp.359-368
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    • 2000
  • Landscape change is the modification and replacement of landscape elements in accordance with human management and natural disturbance on land mosaics. During landscape change, changes in patterns such as heterogeneity, diversity and shape, and juxtaposition of spatial elements are also accompanied. For the sustainable landscape system, therefore, spatial characteristics of the landscape should be considered in implementation of landscape conservation and restoration planning. Short-term changes of land-use and landscape pattern during the 10 years of 1980s and 1990s were investigated in the agriculture-forestry dominated landscape system through the statistics and the analysis of landscape-vegetation map. Study area is Yangdong-myon, Yangpyung-gun (37°27′30"N, 127°46′50"E), Kyonggi-do, in central Korea. Landscape change of this region was significantly related to the recent industrialization according to socio-economic development. Analyses of landscape pattern show that the area of secondary forest sustained by human activity decreased and it was replaced with large exotic plantations during this period. Area of paddy field was also extended. Fractal dimension of the total landscape increased, but that of paddy field area decreased due to rearrangement for mechanized farming. Moreover, the area of landscape management regimes such as plantation and cultivation increased in land mosaics during this period.

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The Change of The Average Discomfort Index from June to September during The Past 10 Years (한반도의 여름철 불쾌지수 특성 분석)

  • Jang, You-Jung;Heo, Hye-Sook;Kim, Baek-Jo;Kim, Seong-Kyoun;Hong, Gi-Man;Lee, Woo-Kyun
    • Journal of Climate Change Research
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    • v.3 no.2
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    • pp.89-100
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    • 2012
  • This study analyzes spatio-temporal variability of discomfort index for summer the during the past ten years(2001~2010) in the Korean Peninsula, and considers the application possibility of discomfort index as a preliminary data for various phenomenon of society based on the analysis. Discomfort index defined as daily representative value was estimated using hourly temperature and humidity data which are observed 60 weather stations managed by Korea Meteorological Administration. The result indicates that the discomfort index in summer keeps the level at which one feels unpleasant, and the level increased steadily as temperature is rising. And discomfort index in 3 pm and on August are the highest during the day and year. Gangwon-do have shown the lowest discomfort index among the provinces. Variability analysis of discomfort index due to climate changes can be used for making policies in various fields such as industry and public health field.

Spatio-Temporal Summer Rainfall Pattern in 2020 from a Rainfall Frequency Perspective (2020년 여름철 강우의 시공간적 특성 분석: 빈도해석을 중심으로)

  • Kim, Yong-Tak;Park, Moonhyung;Kwon, Hyun-Han
    • Journal of Korean Society of Disaster and Security
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    • v.13 no.4
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    • pp.93-104
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    • 2020
  • Climate change has emerged as a social issue, and efforts have been made to overcome it in various ways. However, climate change due to global warming is likely to accelerate further than we expected, and the associated damage is also likely to increase. This tendency is expected to continue in the future, leading to difficulties for the existing water resource management system based on historical data. The precipitation in 2020 caused property damage and loss of life due to the extreme rainfall exceeding the design rainfall with the very unusual prolonged rainy days. With this 2020 flood, we should no longer be passive in managing flood risk due to uncertainties in climate change.

Estimation of Vegetation Carbon Budget in South Korea using Ecosystem Model and Spatio-temporal Environmental Information (생태계 모형과 시공간 환경정보를 이용한 우리나라 식생 탄소 수지 추정)

  • Yoo, Seong-Jin;Lee, Woo-Kyun;Son, Yo-Whan;Ito, Akihiko
    • Korean Journal of Remote Sensing
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    • v.28 no.1
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    • pp.145-157
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    • 2012
  • In this study, we simulated a carbon flux model, so called Vegetation Integrated Simulator for Trace gases (VISIT) using Spatio-temporal Environmental Information, to estimate carbon budgets of vegetation ecosystem in South Korea. As results of the simulation, the model estimated that the annual-average gross primary production (GPP), net primary production (NPP) for 10 years were $91.89Tg\;C\;year^{-1}$, and $40.16Tg\;C\;year^{-1}$, respectively. The model also estimated the vegetation ecosystems in South Korea as a net carbon sink, with a value of $3.51Tg\;C\;year^{-1}$ during the simulation period. Comparing with the anthropogenic emission of South Korea, vegetation ecosystems offsets 3.3% of human emissions as a net carbon sink in 2007. To estimate the carbon budget more accurately, it is important to prepare reliable input datasets. And also, model parameters should be calibrated through comparing with various independent method. The result of this study, however, would be helpful for devising ecosystem management strategies that may help to mitigate global climate change.

Spatio-Temporal Changes in Seasonal Extreme Temperature Events in the Republic of Korea (우리나라 사계절 극한기온현상의 시.공간적 변화)

  • Choi, Gwangyong
    • Journal of the Korean Geographical Society
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    • v.49 no.4
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    • pp.489-508
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    • 2014
  • The purpose of this study is to clarify the spatio-temporal patterns of changes in seasonal extreme temperature events in the Republic of Korea based on daily maximum and minimum temperature data sets observed at 61 weather stations for the recent 40 year period (1973~2012). According to analysis of regional average data, in spring increases of warm days are most distinct, while in summer reductions of cool nights and increases of warm nights are most noticeable. The similar patterns to those in summer are observed in fall, while in winter reductions of cool days and nights are notable. Regardless of the magnitude of urbanization, changes in nighttime extreme temperature events prevail in transitional periods between seasons, while those in daytime extreme temperature events do so only in particular months. In contrast, cool days in spring and summer, warm days in summer and warm nights in winter do not show any statistically-significant changes at most of stations. The sensitivity of seasonal extreme temperature events to increases of seasonal average extreme temperature is greatest in the case of warm days ($+6.3days/^{\circ}C$) and cool nights ($-6.2days/^{\circ}C$) in spring, warm nights ($+10.4days/^{\circ}C$) and days ($+9.5days/^{\circ}C$) in summer, warm days ($+7.7days/^{\circ}C$) in fall, and cool nights ($-4.7/^{\circ}C$) in winter, respectively. These results indicate that changes in seasonal extreme temperature events and their sensitivity to changes in seasonal climate means under a warmer climate are occurring with seasonally and diurnally asymmetric magnitudes in Korea due to complex climate feedbacks.

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Characteristics of Industrial Heritage as Regional Cultural Contents (지역문화콘텐츠로서의 산업유산 특성 - 삿포로와 청주 사례를 중심으로 -)

  • Lee, Byung-min
    • Review of Culture and Economy
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    • v.20 no.2
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    • pp.89-117
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    • 2017
  • As the industrial paradigm shifts and the manufacturing industry declines, many changes also take place in the region as well. In this regard, interest in industrial heritage as a facet of cultural heritage is on the increase. In this paper, the meaning of regional 'cultural contents' as industrial heritage is investigated within the scope of specific region. It is meant to move beyond the viewpoint of considering industrial heritage as only relating to industrial machinery and relevant landmarks from the past. The concept of industrial heritage is established more clearly through the review policy and case study analysis of existing research; the analysis is conducted to investigate the characteristics associated with it, and then to explore how best to utilize it. In particular, this paper attempts to focus on how it operates within these parameters using a spatio-temporal context as much as possible, and concentrating on the recognition and experience of the subject of industrial heritage as being traceable through human story. This research is based on the case of 'Sapporo' which focuses on modern history based on historical importance, and the 'Cheongju' case study, which contrasts the former by focusing on urban regeneration using a spatial lens. This paper identifies the possibility of regional development through the examination of past identity and diversity in the present, and highlights the features that could be linked to future usability and development. In addition, it proposes the possibility that the cycle of regional development could change in the process of the different stages of territorialization, de-territorialization and re-territorialization.