• Title/Summary/Keyword: landscape variables

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Development of Species Distribution Models and Evaluation of Species Richness in Jirisan region (지리산 지역의 생물종 분포모형 구축 및 종풍부도 평가)

  • Kwon, Hyuk Soo;Seo, Chang Wan;Park, Chong Hwa
    • Journal of Korean Society for Geospatial Information Science
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    • v.20 no.3
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    • pp.11-18
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    • 2012
  • Increasing concern about biodiversity has lead to a rise in demand on the spatial assessment of biological resources such as biodiversity assessment, protected area selection, habitat management and restoration in Korea. The purpose of this study is to create species richness map through data collection and modeling techniques for wildlife habitat assessment. The GAM (Generalized Additive Model) is easy to interpret and shows better relationship between environmental variables and a response variable than an existing overlap analysis and GLM (Generalized Linear Model). The study area delineated by a large watershed contains Jirisan national park, Mt. Baekun and Sumjin river with three kinds of protected areas (a national park, a landscape ecology protected area and an otter protected area). We collected the presence-absence data for wildlife (mammals and birds) using a stratified random sampling based on a land cover in the study area and implemented natural and socio-environmental data affecting wildlife habitats. After doing a habitat use analysis and specifying significant factors for each species, we built habitat suitability models using a presence-absence model and created habitat suitability maps for each species. Biodiversity maps were generated by taxa and all species using habitat suitability maps. Significant factors affecting each species habitat were different according to their habitat selection. Although some species like a water deer or a great tit were distributed at the low elevation, most potential habitats for mammals and birds were found at the edge of a national park boundary or near a forest around the medium elevation of a mountain range. This study will be used for a basis on biodiversity assessment and proected area selection carried out by Ministry of Environment.

Harvesting Cost of Tree-length Thinning in a Larix leptolepis Stands (낙엽송 간벌작업에서 전간수확시스템의 작업비용 분석)

  • Cho, Koo-Hyun;Cho, Min-Jae;Han, Han-Sup;Han, Sang-Kyun;Cha, Du-Song
    • Journal of Korean Society of Forest Science
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    • v.104 no.2
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    • pp.221-229
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    • 2015
  • The purpose of study was to broaden our knowledge on the productivity and cost of thinning operations which has become increasingly practiced in Korea. The thinning operations were conducted in a 40-year old larch (Larix leptolepis) stand, including chainsaw felling and processing at the stump, followed by yarding tree-length logs using a Koller K301-4 tower yarder. The logs were further processed and sorted into 1.8 m and 3.6 m log piles at the landing. We used a standard time study method to evaluate key variables that affect the productivity of thinning operations. The total stump-to-pile operational cost was $41,707won/m^3$. The highest cost activity was the yarding phase which cost $20,083won/m^3$ (48.2% of the total cost), followed by the costs of processing treelength materials into marketable log lengths ($12,143won/m^3$; 29.1%), and then by the costs of sorting/piling the processed logs ($5,039won/m^3$; 12.1%). It was interesting to see that felling and processing trees at the stump had low costs at $1,315won/m^3$ (3.2%) and $3,127won/m^3$ (7.5%), respectively. We used the detailed time study data to develop regression equations which were to predict yarding productivity. Our analysis showed that harvesting system cost was highly sensitive to the number of logs, yarding distance and lateral distance per turn, respectively.

A Study on the Image and Visual Preference for the Beautiful Forest Scenery types in Korea (아름다운 산림풍경 유형의 선호도 및 이미지 특성에 관한 연구)

  • Lee, Yeon-Hee;Park, Chan-Woo;Ha, Si-Yeon
    • Journal of Korean Society of Forest Science
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    • v.104 no.4
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    • pp.685-696
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    • 2015
  • This study intends to evaluate visual preference and image for 10 types of forest sceneries which have own distinct characteristics without overlapping each other among 22 types of beautiful forest sceneries based on Korea National Parks. Z scale and paired comparison methods were used to analyze visual preference for forest scenery, and SD scale method was also adopted to assess visual image for forest scenery. Experiments were conducted with 3 different university students groups. The results of this study can be summarized as follows. First, the evaluation results of Z scale (N=70) and paired comparison (N=64) methods show similar visual preference for different types of forest scenery. 'Scenery inside forests' and 'valley and rock' sceneries have the highest level of preference, and 'panorama of ridges', 'ridge of curious rock peaks', and 'waterfall and cliff' also have relatively higher preference level than others. However, 'community of dead trees' has the lowest preference in forest sceneries. Second, the factor analysis outputs of the image scores for beautiful forest scenery types by SD scale (N=66) show 3 factors of 'mysterious charm', 'colorful sense', and 'vividness/variety'. Examined the variables of forest scenery types for each factor, the image of 'mysterious charm' is based on the sceneries of mountain ridges, the image of 'colorful sense' is focused on the sceneries of color-expressed sense of the season, and the image of 'vividness/variety' is based on the sceneries of waterscape and curious rock peaks.

Use of the Quantitatively Transformed Field Soil Structure Description of the US National Pedon Characterization Database to Improve Soil Pedotransfer Function

  • Yoon, Sung-Won;Gimenez, Daniel;Nemes, Attila;Chun, Hyen-Chung;Zhang, Yong-Seon;Sonn, Yeon-Kyu;Kang, Seong-Soo;Kim, Myung-Sook;Kim, Yoo-Hak;Ha, Sang-Keun
    • Korean Journal of Soil Science and Fertilizer
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    • v.44 no.5
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    • pp.944-958
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    • 2011
  • Soil hydraulic properties such as hydraulic conductivity or water retention which are costly to measure can be indirectly generated by soil pedotransfer function (PTF) using easily obtainable soil data. The field soil structure description which is routinely recorded could also be used in PTF as an input to reduce the uncertainty. The purposes of this study were to use qualitative morphological soil structure descriptions and soil structural index into PTF and to evaluate their contribution in the prediction of soil hydraulic properties. We transformed categorical morphological descriptions of soil structure into quantitative values using categorical principal component analysis (CATPCA). This approach was tested with a large data set from the US National Pedon Characterization database with the aid of a categorical regression tree analysis. Six different PTFs were used to predict the saturated hydraulic conductivity and those results were averaged to quantify the uncertainty. Quantified morphological description was successively used in multiple linear regression approach to predict the averaged ensemble saturated conductivity. The selected stepwise regression model with only the transformed morphological variables and structural index as predictors predicted the $K_{sat}$ with $r^2$ = 0.48 (p = 0.018), indicating the feasibility of CATPCA approach. In a regression tree analysis, soil structure index and soil texture turned out to be important factors in the prediction of the hydraulic properties. Among structural descriptions size class turned out to be an important grouping parameter in the regression tree. Bulk density, clay content, W33 and structural index explained clusters selected by a two step clustering technique, implying the morphologically described soil structural features are closely related to soil physical as well as hydraulic properties. Although this study provided relatively new method which related soil structure description to soil structure index, the same approach should be tested using a datasets containing the actual measurement of hydraulic properties. More insight on the predictive power of soil structure index to estimate hydraulic properties would be achieved by considering measured the saturated hydraulic conductivity and the soil water retention.

Subjective Video Quality Evaluation and User Satisfaction according to Screen Size and Content Type : Comparison of UHD and UWV (화면크기와 콘텐츠유형에 따른 주관적 영상품질 평가와 이용자 만족도: UHD와 UWV 비교 분석)

  • Cho, EunSun;Lee, Jin-Myong;Rha, Jong-Youn;Park, Sunny;Koo, Hye-Gyoung;Cho, YongJu;Seo, Jung-Il
    • Journal of Digital Convergence
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    • v.16 no.12
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    • pp.283-292
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    • 2018
  • UHD (Ultra High Definition) broadcasting technology, and UWV (Ultra Wide Vision) which is the high quality panoramic video of wide view angle based on UHD, were commercialized in Korea for the first time in the world, and those are representative realistic video technologies that maximize the user's sense of presence. By comparing the user's subjective reaction of UHD and UWV, the purpose of this study is to systematically establish the user's subjective video quality evaluation. For this purpose, a large screen projection experiment is designed by setting the screen size (4k x 2k, 8k x 2k) and content types (sports, landscape, concert) as variables to measure the user's subjective video quality evaluation and satisfaction. As a result of the study, the users' evaluation of UWV was higher than UHD in all items of subjective video quality, and satisfaction. Moreover, the results showed the significant differences depending on the video contents. Based on the results of the research, the study proposed the points necessary for the development and commercialization of UWV panoramic technology, and suggestions for the future research.

A Methodology for Selection of Habitat Management Areas for Amphibians and Reptiles Considering Soil Loss (토양유실을 고려한 양서파충류의 서식지 관리지역 선정방법)

  • Kim, Ji-Yeon;Lee, Dong-Kun;Mo, Yong-Won
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.21 no.6
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    • pp.55-69
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    • 2018
  • As disaster risk and climate change volatility increase, there are more efforts to adapt to disasters such as forest fires, floods, and landslides. Most of the research, however, is about influence of human activities on disaster and there is few research on disaster adaptation for species. Previous studies focusing on biodiversity in selecting conservation areas have not addressed threats of disaster in the habitats for species. The natural disasters sometimes play role of drivers of ecological successions in the long run, but they might cause serious problems for the conservation of vulnerable species which are endangered. The purpose of this study is to determine whether soil loss (SL) is effective in selecting habitat management areas for amphibians and reptiles. RUSLE model was used to calculate soil loss (SL) and the distribution of each species (SD) was computed with MaxEnt model to find out the biodiversity index. In order to select the habitat management area, we estimated the different results depending if value of soil loss was applied or not by using MARXAN, a conservation priority selection tool. With using MARXAN, conservation goals can be achieved according to the scenario objectives, and the study has been made to meet the minimum habitat area. Finally, the results are expressed in two; 1) the result of soil loss and biodiversity with MATRIX method and 2) the result of regional difference calculated with MARXAN conservation prioritization considering soil loss. The first result indicates that the area with high soil loss and low species diversity have lower conservation values and thus can be managed as natural disturbances. In the area where soil loss is high and species diversity is also high, it becomes where a disaster mitigation action should be taken for the species. According to the conservation priorities of the second result, higher effectiveness of conservation was obtained with fewer area when it considered SL in addition to SD, compared to when considered only biodiversity. When the SL was not taken into consideration, forest area with high distribution of species were important, but when SL considered, the agricultural area or downstream of the river were represented to be a major part of habitats. If more species data or disaster parameters other than soil loss are added as variables later, it could contribute as a reference material for decision-making to achieve various purposes.

Factors Affecting Disaster Victims' Quality of Life: The Uljin and Samcheok Forest Fires (산불피해자의 삶의 질에 영향을 미치는 요인: 울진⋅삼척 산불을 중심으로)

  • Hee-Ji Kang;Dong-Hoon Kim;Jae-Ok Ha;Chang-Hyou Kim;Sang-Yoel Han
    • Journal of Korean Society of Forest Science
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    • v.112 no.1
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    • pp.105-116
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    • 2023
  • As forest fires' scale has increased, they have become disasters that destroy not only forests but also property, human psychological balance, and even human lives. As a result, governmental support has become a crucial part of the forest fire restoration process. Quickly restoring victims' quality of life (QOL) from not only an ecological perspective but also from their human perspective has become an important goal. Therefore, through structural equation modeling, this study analyzed effects of government support, post-traumatic stress disorder (PTSD), and resilience on 195 Uljin and Samcheok forest fire victims' QOL. In the final research model, the total standardized effect on QOL of government support to PTSD and resilience was found to have significant effect (0.417). By path, the effect of government support on QOL through resilience was verified as 0.172. Examination of the path between latent variables revealed that resilience had the greatest influence on QOL, and government support had a significant effect, thus confirming that they were the main factors affecting QOL.

A New Generational Spirit?: A Study on Welfare Attitude of Korean Young Generations (새로운 세대정신?: 한국청년세대의 복지태도 지형연구)

  • Sin-Young Kim
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.6
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    • pp.17-23
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    • 2023
  • This study purports to explore the landscape of welfare attitudes of young generation of Korea in their 20s and 30s focusing upon potential differences from those of older generations. Korea has recently been in the significant debate on pension reform and the disadvantages of relatively young generations has been on of the most crucial issues during the reform. Survey data from 17th Korean Welfare Panel are analyzed and such variable as attitudes toward government expenditure on public pension, health care, old age support, poverty, family and child care and so on. In addition, welfare-related variables such as universalism vs selectivism, tax increase for welfare expenditure, and political orientation are to be analyzed. The results show several findings. First of all, correspondence analysis shows that young generation in Korea are strongly associated with higher education and full time employment compared to older generations. Secondly, the most interested welfare issues of young generations are housing and child support. Moreover, young generations' attitudes toward government expenditure increase differ from those of older generations on the issues of public pension, housing, and family and child support. Lastly, political orientation of those young generation tend to be progressive and they support universalism in welfare policy, but they do not support tax increase for welfare purpose, which, I would say, is inconsistent.

Tree species migration to north and expansion in their habitat under future climate: an analysis of eight tree species Khyber Pakhtunkhwa, Pakistan

  • Muhammad Abdullah Durrani;Rohma Raza;Muhammad Shakil;Shakeel Sabir;Muhammad Danish
    • Journal of Ecology and Environment
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    • v.48 no.1
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    • pp.96-109
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    • 2024
  • Background: Khyber Pakhtunkhwa government initiated the Billion Tree Tsunami Afforestation Project including regeneration and afforestation approaches. An effort was made to assess the distribution characteristics of afforested species under present and future climatic scenarios using ecological niche modelling. For sustainable forest management, landscape ecology can play a significant role. A significant change in the potential distribution of tree species is expected globally with changing climate. Ecological niche modeling provides the valuable information about the current and future distribution of species that can play crucial role in deciding the potential sites for afforestation which can be used by government institutes for afforestation programs. In this context, the potential distribution of 8 tree species, Cedrus deodara, Dalbergia sissoo, Juglans regia, Pinus wallichiana, Eucalyptus camaldulensis, Senegalia modesta, Populus ciliata, and Vachellia nilotica was modeled. Results: Maxent species distribution model was used to predict current and future distribution of tree species using bioclimatic variables along with soil type and elevation. Future climate scenarios, shared socio-economic pathways (SSP)2-4.5 and SSP5-8.5 were considered for the years 2041-2060 and 2081-2100. The model predicted high risk of decreasing potential distribution under SSP2-4.5 and SSP5-8.5 climate change scenarios for years 2041-2060 and 2081-2100, respectively. Recent afforestation conservation sites of these 8 tree species do not fall within their predicted potential habitat for SSP2-4.5 and SSP5-8.5 climate scenarios. Conclusions: Each tree species responded independently in terms of its potential habitat to future climatic conditions. Cedrus deodara and P. ciliata are predicted to migrate to higher altitude towards north in present and future climate scenarios. Habitat of D. sissoo, P. wallichiana, J. regia, and V. nilotica is practiced to be declined in future climate scenarios. Eucalyptus camaldulensis is expected to be expanded its suitability area in future with eastward shift. Senegalia modesta habitat increased in the middle of the century but decreased afterwards in later half of the century. The changing and shifting forests create challenges for sustainable landscapes. Therefore, the study is an attempt to provide management tools for monitoring the climate change-driven shifting of forest landscapes.

Pergola's Shading Effects on the Thermal Comfort Index in the Summer Middays (여름철 낮 그늘시렁의 차양이 온열쾌적 지표에 미치는 영향)

  • Ryu, Nam-Hyong;Lee, Chun-Seok
    • Journal of the Korean Institute of Landscape Architecture
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    • v.41 no.6
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    • pp.52-61
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    • 2013
  • This study was conducted to investigate the effects of pergola's shading on the thermal comfort index in the summer. The 3 type of pergolas($4m{\times}4m{\times}h2.7m$) which were screened overhead(I)/overhead west(II)/overhead west north(III) plane with reed blind for summer shading and winter wind break, were constructed on the 4th floor rooftop. Thereafter the meteorological variables(air temperature, humidity, radiation, and wind speed) of pergola I, III and rooftop were measured from 14 to 16 August 2013(1st experiment), those of pergola I, II and rooftop were measured from 26 to 28 August 2013(2nd experiment). The effects of pergola's shading on the radiation environment and mean radiant temperature($T_{mrt}$), standard effective temperature($SET^*$) were as follows. The maximum 1 h mean values of differences ${\Delta}$ of the sums of shortwave radiant flux densities absorbed by the human body (${\Delta}K_{abs,max}$) between pergola I, III and nearby sunny rooftop were $-119W/m^2$, $-158W/m^2$, those between pergola I, II and rooftop were $-145W/m^2$, $-159W/m^2$. The maximum 1 h mean values of differences ${\Delta}$ of the sums of long wave radiant flux densities absorbed by the human body (${\Delta}L_{abs,max}$) between pergola I, III and nearby sunny rooftop, were $-15W/m^2$, $-17W/m^2$, those between pergola I, II and nearby rooftop, were $-8W/m^2$, $-7W/m^2$. The response of the direction dependent long wave radiant flux densities $L_1$ on the pergola's shading turned out to be distinctly weaker as compared to shortwave radiant flux densities $K_1$. The pergola's shading leads to a lowering of $T_{mrt}$ and $SET^*$. The peak values of $T_{mrt}$ absorbed by the human body were decreased $16^{\circ}C$ and $21.4^{\circ}C$ under pergola I and III as compared to that of nearby rooftop in the 1st experiment. Those were decreased $18.8^{\circ}C$ and $20.8^{\circ}C$ under pergola I and II as compared to that of nearby rooftop in the 2nd experiment. The peak values of $SET^*$ absorbed by the human body were decreased $2.9^{\circ}C$ and $2.6^{\circ}C$ under pergola I and III as compared to that of nearby rooftop in the 1st experiment. Those were decreased $3.5^{\circ}C$ and $2.6^{\circ}C$ under pergola I and II as compared to that of nearby rooftop in the 2nd experiment. The relative $SET^*$ decrease in pergola II, III compared to nearby sunny rooftop $SET^*$ were lower than that in pergola I, revealing the influence of the wind speed. Therefore it is essential to design pergola to maximize wind speed and minimize solar radiation to achieve comfort in the hot summer. The $SET^*$ under pergola I, III were exceeded $28.7^{\circ}C$ and $30.4^{\circ}C$ which were the upper limit of thermal comfort and tolerable zone during all most daytimes in the 1st experiment(maximum air temperature $37.5^{\circ}C$). The $SET^*$ under pergola I was exceeded $28.7^{\circ}C$ which was the upper limit of thermal comfort zone at 13h, that under pergola II was exceeded $28.7^{\circ}C$ from 8h to 14h, meanwhile the $SET^*$ under pergola I, II were within thermal tolerable zone during most daytimes in the 2nd experiment(maximum air temperature $34.4^{\circ}C$). Therefore to ensure the thermal comfort of pergola for summer hottest days, pergola should be shaded with not only reed blind but also climbing and shade plants. $T_{mrt}$ and $SET^*$ were suitable index for the evaluation of pergola's shading effects and outdoors.