• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.23 no.4
• /
• pp.367-374
• /
• 2005

Recently, forest damage has occurred often and made big issues. Among them, the damage by forest fire is not only damage of itself but also being connected with secondary damage like a flood. This is the fact that a forest fire is caused rather artificially by people than nature. In this study, we try to investigate damage of a forest fire through spectral reflectance of a plant community surveyed using a near infrared CCD camera and a SPM (Spectral Radiometer) as advanced work to use satellite image data. That is, damage of a forest fire by the naked eye observation was divided into the No damage, the light damage, the serious damage and we estimated activity of forest and grasped revival possibility of forest. Through correlation analysis between the spectral reflectance by SPM and the near infrared CCD camera, we could get high correlation in the No damage and light damage. Therefore, when we surveyed damage of a forest fire, we could grasp damage, that is hardly observed by the naked eye by, using jointly the spectral radiometer and the near infrared CCD camera.

• Korean Journal of Remote Sensing
• /
• v.35 no.6_2
• /
• pp.1133-1148
• /
• 2019

Tree growth and vitality in forest shows seasonal changes. So, in order to detect forest damage accurately, we have to use satellite images before and after damages taken at the same season. However, temporal resolution of high or medium resolution images is very low,so it is not easy to acquire satellite images of the same seasons. Therefore, in this study, we estimated spectral information of the same DOY using time-series Landsat images and used the estimates as reference values to assess forest damages. The study site is Hwasun, Jeollanam-do, where forest damage occurred due to hail and drought in 2017. Time-series vegetation index (NDVI, EVI, NDMI) maps were produced using all Landsat 8 images taken in the past 3 years. Daily normal vegetation index maps were produced through cloud removal and data interpolation processes. We analyzed the difference of daily normal vegetation index value before damage event and vegetation index value after event at the same DOY, and applied the criteria of forest damage. Finally, forest damage map based on daily normal vegetation index was produced. Forest damage map based on Landsat images could detect better subtle changes of vegetation vitality than the existing map based on UAV images. In the extreme damage areas, forest damage map based on NDMI using the SWIR band showed similar results to the existing forest damage map. The daily normal vegetation index map can used to detect forest damage more rapidly and accurately.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.37 no.5
• /
• pp.351-357
• /
• 2019

UAV (Unmanned Aerial Vehicle) images can be exploited for rapid forest fire damage assessment by virtue of UAV systems' advantages. In 2019, catastrophic forest fire occurred in Goseong and Sokcho, Korea and burned 1,757 hectares of forests. We visited the town in Goseong where suffered the most severe damage and conducted UAV flights for forest fire damage assessment. In this study, economic and rapid damage assessment method for forest fire has been proposed using UAV systems equipped with only a RGB sensor. First, forest masking was performed using automatic elevation thresholding to extract forest area. Then ExG (Excess Green) vegetation index which can be calculated without near-infrared band was adopted to extract damaged forests. In addition, entropy filtering was applied to ExG for better differentiation between damaged and non-damaged forest. We could confirm that the proposed forest masking can screen out non-forest land covers such as bare soil, agriculture lands, and artificial objects. In addition, entropy filtering enhanced the ExG homogeneity difference between damaged and non-damaged forests. The automatically detected damaged forests of the proposed method showed high accuracy of 87%.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.7 no.4
• /
• pp.258-264
• /
• 2005

The objectives of this study were to study 1) emergence of pine bark beetles, 2) larval density in residual timber on Idlest land by each felling season, and 3) the secondary damage rates in the tended forest. Pine forest land which had undergone tending had a higher secondary damage ratio $(59.6\%)$ by pine bark beetles than forest land that was not tended $(2.8\%)$. The number of escape holes averaged 11.3 0.31 per $250 cm^2$ on the bark of leaf trees in the tended forest. The number of escape holes was higher in the Jinju site than in the Hamyang site. The larval habitat density of pine bark beetles as compared with each felling period was higher after mid-October than in forests tended early in October. Thus, forests should be tended before early October in order to prevent secondary damage from pine bark beetles. Secondary damage in the tended forest was higher in the upper part $(75.5\%)$ of the tree crown than in the lower part $(49.2\%)$. The damage was higher in terminal shoots $(80\%)$ than in lateral shoots $(48\%)$. Therefore, secondary damage by pine bark beetles can cause deterioration of the elongation growth of the forest trees. In conclusion, if by-products of tended pine forest forests are neglected, they will be utilized as a propagation site for pine bark beetles (Blastophagus piniperda L). The propagated adults will damage the tender shoots of the leaf trees and thus seriously limittheir elongation.

• Journal of Environmental Impact Assessment
• /
• v.32 no.6
• /
• pp.463-472
• /
• 2023

The amount of damage and the area of damage to forest fires are increasing globally, and the effectiveness analysis of the restoration method after the damage is performed insufficient. This study calculated the area of forest fire damage was calculated using Sentinel-2B satellite images and stack map and the intensity of forest fire damage is analyzed according to the forest type. In addition, the vegetation index was calculated using various wavelength bands. Based on the results, the vegetation resilience by the restoration method was quantitatively. As results, areas with a high proportion of coniferous forests suffered high intensity forest fire damage, and areas with a relatively high ratio of mixed and broad-leaved forests tended to have low forest fire damage. Also, artificial forests showed a recovery of about 92.7% compared to before forest fires and natural forests showed a recovery of about 99.6% from the result of analyzing vegetation resilience in artificial and natural forests after forest fires. Accordingly, it was confirmed that natural forests after forest fire damage had superior vegetation resilience compared to artificial forests. It can be proposed that this study is meaningful in providing important information for efficiently restoring the affected target site and the selection criteria for trees to reduce forest fire damage through the evaluation of vegetation resilience by the intensity of forest fire damage and restoration methods.

• Journal of computational fluids engineering
• /
• v.18 no.1
• /
• pp.69-76
• /
• 2013

To reduce the damage from the coastal disaster such as typhoon and tsunami, a possible option is the eco-friendly approach to minimize the destruction of ecological system. One of feasible idea is the forest for damage prevention artificially arranged along the beach. To understand a precise physics on the flow before and after the forest, we use a CFD method. In this paper, a three-dimensional numerical model has been constructed based on tree cases in a real forest located at Byin-myeon, Seocheon-gun, Chungnam. The CFD computation using a commercial code COMSOL multiphysics is performed for the distribution of real spatial coordinate of each tree. Through this investigation, the CFD techniques are shown to be applied to the research of forest composition plan. The physics in the regime from laminar to turbulent flow is qualitatively explained, and the obtained data are compared one another quantitatively.

• Journal of Korean Society of Forest Science
• /
• v.97 no.6
• /
• pp.656-660
• /
• 2008

This study is carried out to minimize the damage to the forest road when locating strip roads in the future for stability of timberland after afforestation by assessing the factors that affect the damage on the forest road surface and making appropriate constructing standards. Major factors that influence damage to the strip road surface were location, longitudinal gradients, soil types, cross-section shape in order of influence on damage. it is considered that structural road factors like longitudinal gradients, road width, location factors such as construction location, slope gradients and road material like soil types were greatly related to occurrence of road surface damage. Damage occurrences in the forest road were severe at the valley, longitudinal gradients of over 24%, weathered granite soil, concave of road position, road width of over 3.0 m. stability was high at longitudinal gradients of 4~24%, road width of under 3.0 m, ridge of road position, straight slope, soil materials. The evaluation table of damage possibility on forest road was manufactured by discriminant analysis using Quantification theory(II). The results showed that the discriminant ratios was 79.4% and this table was available for forest manager.

• Journal of Forest and Environmental Science
• /
• v.35 no.3
• /
• pp.197-204
• /
• 2019

A tree-length harvesting system using the HAM300, which is mounted on a farm tractor prototype machine, have been recently introduced in South Korea for thinning old (>30 years) forests. However, no research has previously been conducted on the characteristics of residual stand damage associated with cable yarding systems on thinning treatment stands in South Korea. Therefore, there were assessed on the degree and quantity of residual stand damage caused by felling and yarding process to broaden the knowledge of residual stand damage on semi-mechanized skyline thinning operations. This study investigated scar size, direction, area, shape type and their distribution on the residual stand damage caused by felling and yarding operations. Damage to residual trees was generated for 7.4% and 6.9% of residual trees in felling and yarding operations, respectively. Damaged direction of scars was located in front-side (38.9%) and up-side (34.7%) for felling operations while the highest scar damage was found on down-side (44.6%) for yarding operations. Scar heights of felling damage were higher than those of yarding damage. In yarding operation, the most of the scars was located within l0m from the center of the skyline corridor. These results should be useful information for forest managers and landowners to reduce residual stand damages and retain valuable timber volume from thinning treatments.

• Journal of Korean Society for Geospatial Information Science
• /
• v.24 no.3
• /
• pp.49-58
• /
• 2016

Applications of drone in various fields have been increasing in recent years. Drone has great potential for forest management. Therefore this paper is using drone for forest damage areas. Forest damage areas is divided into caused by anthropogenic and occurs naturally, the possibility of disasters, such as slope sliding, slope failures and landslides, sediment runoff exists. Therefore, this research was to utilize the drone photogrammetry to perform the damage analysis of forest damage areas. Geometrical treatment processing results in Drone Photogrammetry, the plane position error RMSE was ${\pm}0.034m$, the elevation error RMSE was ${\pm}0.017m$. The plane position error of orthophoto RMSE was ${\pm}0.083m$, the elevation error of digital elevation model RMSE was ${\pm}0.085m$. In addition, It was possible to current state analysis of damage in forest damage areas of airborne LiDAR data of before forest damage and drone photogrammetry data of after forest damage. and application of drone photogrammetry for production base data for restoration and design in forest damage areas.

• Journal of Korean Society of Forest Science
• /
• v.95 no.2
• /
• pp.216-219
• /
• 2006

After long exposure to low-density $SO_2$ the five tree species showed different changes in their visible damage: Ailanthus altissima showed no visible damage; Acanthopanax sessiliflorus, Populus alba ${\times}$ Populus glandulosa, and Platanus orientalis showed typical damage of yellow spots on their leaves; and Liriodendron tulipifera showed serious damage on the end of leaf tip. The photosynthesis rate of Liriodendron tulipifera and Acanthopanax sessiliflorus was usually lower than the control group: Ailanthus altissima, Populus alba ${\times}$ Populus glandulosa, and Platanus orientalis showed no difference from the control group, while Acanthopanax sessiliflorus and Liriodendron tulipifera showed large changes. In regard to the light compensation points, Ailanthus altissima showed similar values, Populus alba ${\times}$ Populus glandulosa and Platanus orientalis exposed to $SO_2$, showed 3 to $5{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ higher values than the control group, and Acanthopanax sessiliflorus and Liriodendron tulipifera exposed to $SO_2$ showed approximately twice higher light compensation points.