• Title/Summary/Keyword: 수관높이모형

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The Analysis of Forest Fire Fuel Structure Through the Development of Crown Fuel Vertical Distribution Model: A Case Study on Managed and Unmanaged Stands of Pinus densiflora in the Gyeongbuk Province (수관연료 수직분포모델 개발을 통한 산불연료구조 분석: 경북지역의 소나무림 산림시업지와 비시업지를 대상으로)

  • Lee, Sun Joo;Kwon, Chun Geun;Kim, Sung Yong
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.23 no.1
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    • pp.46-54
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    • 2021
  • This study compared and analyzed the effects of forest tending works on the vertical distribution of wildfire fuel loads on Pinus densiflora stands in Gyeongbuk province. The study sites were located in Youngju and Bonghwa in Pinus densiflora stands. A total of 10 sample trees were collected for the development of the crown fuel vertical distribution model. The 6th NFI (National Forest Inventory) selected a sample point that only extracted from managed and unmanaged stands of Pinus densiflora in the Gyeongbuk province. The fitness index (F.I.) of the two models developed was 0.984 to 0.989, with the estimated parameter showing statistical significance (P<0.05). A s a results, the vertical distribution of wildfire fuel loads range of unmanaged stands was from 1m to 11m with the largest distribution at point 5m at the tree height. On the other hand, the vertical distribution of wildfire fuel loads range of the managed stands was from 1m to 15m with the largest distribution at the point of 8m at the tree height. The canopy bulk density was 0.16kg/㎥ for the managed stands and 0.25kg/㎥ for the unmanaged stands, unmanaged stands were about 1.6 times more than managed stands. This result is expected to be available for simulation through the implementation of the 3D model as crown fuel was analyzed in three dimensions.

Comparison of Accuracy between Analysis Tree Detection in UAV Aerial Image Analysis and Quadrat Method for Estimating the Number of Treesto be Removed in the Environmental Impact Assessment (환경영향평가의 훼손수목량 추정을 위한 드론영상 분석법과 방형구법의 정확성 비교)

  • Park, Minkyu
    • Journal of Environmental Impact Assessment
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    • v.30 no.3
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    • pp.155-163
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    • 2021
  • The number of trees to be removed trees (ART) in the environmental impact assessment is an environmental indicator used in various parts such as greenhouse gas emissions and waste of forest trees calculation. Until now, the ART has depended on the forest tree density of the vegetation survey, and the uncertainty of estimating the amount of removed trees has increased due to the sampling bias. A full-scale survey can be offered as an alternative to improve the accuracy of ART, but the reality is that it is impossible. As an alternative, there is an individual tree detection using aerial image (ITD), and in this study, we compared the ARTs estimated by full-scale survey, sample survey, and ITD. According to the research results, compared to the result of full-scale survey, the result of ITD was overestimated by 25. While 58 were overestimated by the sample survey (average). However, as the sample survey is an estimate based on random samples, ART will be overestimated or underestimated depending on the number and size of quadrats.

Survival Analysis of Forest Fire-Damaged Korean Red Pine (Pinus densiflora) using the Cox's Proportional Hazard Model (콕스 비례위험모형을 이용한 산불피해 소나무의 생존분석)

  • Jeong Hyeon Bae;Yu Gyeong Jung;Su Jung Ahn;Won Seok Kang;Young Geun Lee
    • Journal of Korean Society of Forest Science
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    • v.113 no.2
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    • pp.187-197
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    • 2024
  • In this study, we aimed to identify the factors influencing post-fire mortality in Korean red pine (Pinus densiflora) using Cox's proportional hazards model and analyze the impact of these factors. We monitored the mortality rate of fire-damaged pine trees for seven years after a forest fire. Our survival analysis revealed that the risk of mortality increased with higher values of the delta normalized difference vegetation index (dNDVI), delat normalized burn ratio (dNBR), bark scorch index (BSI), bark scorch height (BSH) and slope. Conversely, the risk of mortality decreased with higher elevation, greater diameter at breast height (DBH), and higher value of delta moisture stress index (dMSI) (p < 0.01). Verification of the proportional hazards assumption for each variable showed that all factors, except slope aspect, were suitable for the model and significantly influenced fire occurrence. Among the variables, BSI caused the greatest change in the survival curves (p < 0.0001). The environmental change factors determined through remote sensing also significantly influenced the survival rates (p < 0.0001). These results will be useful in establishing restoration plans considering the potential mortality risk of Korean red pine after a forest fire.