• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.3
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• pp.207-216
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• 2015

The study was conducted to determine the effects of forest restoration methods and stand structure on solar radiation, air temperature, relative humidity, soil temperature, and soil water content, based on volume, in forest stand after forest fire. The changes of the micro-climate elements in naturally and artificially restored forest after forest fire were measured in Goseong and Samcheok, Gangwon province. Pinus spp. were commonly appeared in ridges, barren lands or planted areas of the study sites while the other areas were dominated by Quercus spp. In the early stage, trees in the naturally regenerated site grow better than the trees in artificially rehabilitated site. However, the growth ratio rapidly decreased by time passed in natural regeneration area. The environmental conditions (solar radiation, air temperature, relative humidity, soil temperature and soil water content) were significantly different by the regions and the methods (p<.05). However, the coefficients of variations of the environmental conditions were not significantly different at 95% confidence level. As the coverage and tree height in crown layer increased, the relative humidity and soil water content were increased while the temperature and solar radiation were decreased. Especially, the relative humidity, solar radiation, and soil water content were clearly affected by the tree height and coverage ratio ($R^2$ means from 0.628 to 0.924). Even though the data should have collected at least more than 5 years in meteorological analysis, the two year results show some clear relationship between forest structure and microclimate elements.

• Journal of Korean Society of Forest Science
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• v.107 no.1
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• pp.108-111
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• 2018

Increasing soil surface roughness can be effective in enhancing infiltration of rainfall and depression storage capacity of forest soil and reducing surface run-off. In this study, a forest slope with hemispherical depressions shows greater infiltration of water, whereas depression storage capacity is higher in soil with depressions perpendicular to a water flow pathway. Soil pitting or forming surface depressions can be used as a countermeasure after forest fires and a practical way to reduce drought stress of forest soil.

• Journal of Korean Society of Forest Science
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• v.62 no.1
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• pp.43-52
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• 1983

The purpose of this study was to measure the changes in soil properties and forest vegetation after surface fire, which had occured on June 5, 1983 in Mt. Gwanag, Kyunggi-do. Moisture content, organic matter and acidity of soil increased just after the fire and then dropped down up to those of unfired areas as time goes. Also total nitrogen, available phosphorous exchangeable base had the similar trend to moisture, organic matter and acidity. Most of the exchangeable bases in surface soil except for sodium were higher than those in sub-soil. No changes in soil texture by the fire were found. Increasers, decreasers, invaders and neutral species could be classified according to the relative importance value of each species. Species diversity was reduced just after the fire and increased gradually afterward. Diversity in the southeast slope was higher than that in the southwest slope. Due to the fire, evenness of woody plants decreased continuously while that of herbs increased. Species similarity was shown greater at fired areas than at unfired areas.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.3
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• pp.135-142
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• 2001

This study attempts to categorizes the factors of forest fire occurrences based on regional meteorologic data and general forest no characteristics of 18 cities and guns in Kangwon province. lo accomplish this goal, some statistical analyses such as analysis of variance, correspondence analysis and multidimensional scaling were adopted. To reveal the forest fires pattern of study region, a categorization process was conducted by employing the quantification approach which modified and quantified the metric-data of fire occurrence dates. Also, The fire occurrence similarity was compared by using multidimensional scaling for each study region. The major results are summarized as follows: It was found that the meteorological factors emerged as different to each region are average and maximum temperature, minimum dew point temperature and average and maximum wind speed. In the result of correspondence analysis representing relationships between fire causes and study regions, Kangrung is caused by arsonist, Chulwon, Hwachen and Yanggu caused by military factor, Sokcho and Chunchen caused by the debris burning, and Samchuk caused by general man-caused fires, respectively. Finally, the forest fire occurrence pattern of this study regions were divided into five areas such as, group I including Samchuk, Kangryung, Chunchen, Wonju, Hongchen and Hhoingsung, group II including Donghae, Taebaek, Yangyang and Pyongchang, group III including Jungsun, Chulwon and Whachen, group Ⅵ including Gosung, Injae and Yanggu, and group V including Shokcho and Youngwol.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.274-274
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• 2021

토양수분은 가뭄, 홍수, 산불 및 산사태 등 자연재해 발생에 직간접적으로 영향을 미치기 때문에, 시·공간적으로 연속적인 토양수분 관측이 필요하다. 과거에는 TDR (Time Domain Reflectometry) 관측 장비를 설치하여 토양수분의 변화를 관측하였으나, 이러한 지점관측의 경우 하나의 관측지점에서 토양수분을 관측하기 때문에 공간적인 토양수분 변화를 나타내지 못한다. 최근 이러한 문제를 해결하기 위하여 인공위성 이미지 자료를 이용한 토양수분 산정에 관한 연구가 활발히 수행되고 있다. 그러나 SMOS (Soil Moisture and Ocean Salinity), SMAP (Soil Moisture Active Passive)와 같은 다양한 위성에서 관측된 토양수분은 낮은 공간해상도로 인한 불확실성이 커지는 단점이 있다. 최근 이러한 한계를 극복하기 위하여 광학위성영상과 달리 날씨의 영향을 받지 않으며 고해상도 이미지자료를 제공하는 Sentinel-1A/B 위성을 활용하여 토양수분을 관측하는 연구가 진행되고 있다. Sentinel-1은 10m의 높은 공간해상도를 제공하지만, 1~2주 주기로 영상취득이 가능하기 때문에 재방문시기와 같은 시간해상도 문제가 발생한다. 따라서 본 연구에서는 Sentinel-1A/B SAR 기반 후방산란계수와 농촌진흥청에서 제공하는 TDR 기반 토양수분 실측값을 이용하여 우리나라 토양수분 공간분포를 산정하였다. 산정된 Sentinel-1A/B 기반 토양수분과 토양수분자료동화기법을 연계하여 토양의 수리학적 매개변수를 추출하였으며, 추출된 매개변수와 기상자료를 이용하여 장기간(2001~2018) 일별 토양수분 공간분포를 산정하였다.

• The Korean Journal of Soil Zoology
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• v.5 no.2
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• pp.47-62
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• 2000

This study investigated the effect of soil animals at forest fire area, and it carried out the mountain located at Jundae Ri, Houeng-chen Myen, Ha-dong Gun, Kyoung-Nam Province, southern part of Korea, where burned out about 50 hectars on April 11, 1997. Vegetation of the examined area absolutely dominated with the pines of 7-14 cm in diameter and 20 to 30 years old and the rest were covered with mixed forest with a shrub such as the oak (Quereus mongolia Fisch, Quereus variabilis BI, Quereus dentana Thunb), snowbell(Styrax japonica, S, et, z), lacquer tree (Rhus trichocarpa Mig), azalea (Rhododendron mucronulatum Turcz), etc. And there were simple area organized as a herbaceous plant, and the burnt area was poor experimental sites, where litter layer and herbaceous plant disappeard due to fire, and the unburnt area was rich in surface plant, dead leaves, twigs, etc. But the ground cover vegetations were poor in the unburnt area. The distribution of each animal groups, the seasonal fluctuation in population density, the biomass of meso$.$macroarthropods and the relationship between soil animal and some environmental factors were investigated and analyzed at each experimental area. The result are summarized as follow: 1. Identificated 257,087 individuals of soil microarthropods were classified into 7 classes and 24 orders of Arachinida, Insecta, Chilopoda, Symphyla, Diplopoda, Isopoda and Oligochaeta., and identified 8,006 individuals of the total meso$.$macroarthropods were classified into 7 classes and 20 orders of Arachinida, Insecta, Chilopoda, Symphyla, Diplopoda, Isopoda and Oligochaeta. 2. Among the total soil microarthropods, Arachinida formed 70.9%, followed by Insecta for 28.4% and among the total meso$.$macroarthropod , Insecta formed 57.6%, followed by Chilopoda for 23.8%.

• Journal of Korea Soil Environment Society
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• v.4 no.1
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• pp.119-126
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• 1999

This study was carried out to estimate the effect of forest fire on physical and chemical properties of soil The forest fire was in April 1995 at Kongju of Chungnam. Soil samples were collected at 0~5cm, 5~10cm, and 10~20cm soil depths in September 1998 from the burned and unburned sites. Soil organic matter concentrations at 0~5cm and 5~10cm soil depths were significantly greater in unburned site than in burned site. Soil concentrations were greater in unburned site than in burned site at all soil depths. Cation exchange capacity was significantly higher in unburned site than in burned site at 0~5cm soil depth. There were no differences in available soil P, exchangeable soil K, Ca, and Mg, and pH of soil between burned and unburned sites. Soil water content at 0~5cm soil depth was significantly greater in unburned site than in burned site. Bulk density at 0~5cm soil depth was significantly higher in burned site than in unburned site. Forest fire had an adverse effect on physical and chemical properties of soil in this study, Burning of vegetation and forest 리oor organic matter in burned site may reduce organic matter supply to soil and increase soil erosion. Consequently, forest fire may have adverse influence on long-term site productivity.

• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.1
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• pp.17-25
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• 2013

In this paper we interpreted the changes in wind field over complex mountainous terrains. The results of our study can be applied for predicting the direction of fire spread and for establishing strategies for fire prevention. The study area is bounded by $12{\times}12$ km domains of the Samcheok's long-term ecological research (LTER) site located in the east coast, in which a large-fire had occurred from 7 to 13 April 2000. Because of the area's complex topography, we compared the result of the Weather Research and Forecasting (WRF) mesoscale model with those observed by four automated weather stations. The WRF simulation overestimated the wind speed by 5 to 8 m/s (~200%) in comparison with those from four automated weather stations. The wind directions observed by the AWSs were from various directions whereas those from WRF model were mostly west wind at all stations. Overall, the simulations by the WRF mesoscale models were not appropriate for the estimation of microscale wind fields over complex mountainous areas. To overcome such inadequacy of reproducing the wind fields, we employed the ENVI-met model over Samcheok's LTER site. In order to test the model's sensitivity with the terrain effects, experimental simulations were conducted with various initial conditions. The simulation results of the ENVI-met model showed a reasonable agreement in wind speeds (about 70% accuracy) with those of the four AWSs. Also, that the variations in wind directions agreed reasonably well with changes in terrain effect. We concluded that the ENVI-met model is more appropriate in representing the microscale wind field over complex mountain terrains, which is required to predict fire spread and to establish strategies for forest fire prevention.

• Korean Journal of Remote Sensing
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• v.36 no.5_3
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• pp.1109-1123
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• 2020

In South Korea with forest as a major land cover class (over 60% of the country), many wildfires occur every year. Wildfires weaken the shear strength of the soil, forming a layer of soil that is vulnerable to landslides. It is important to identify the severity of a wildfire as well as the burned area to sustainably manage the forest. Although satellite remote sensing has been widely used to map wildfire severity, it is often difficult to determine the severity using only the temporal change of satellite-derived indices such as Normalized Difference Vegetation Index (NDVI) and Normalized Burn Ratio (NBR). In this study, we proposed an approach for determining wildfire severity based on machine learning through the synergistic use of Sentinel-1A Synthetic Aperture Radar-C data and Sentinel-2A Multi Spectral Instrument data. Three wildfire cases-Samcheok in May 2017, Gangreung·Donghae in April 2019, and Gosung·Sokcho in April 2019-were used for developing wildfire severity mapping models with three machine learning algorithms (i.e., Random Forest, Logistic Regression, and Support Vector Machine). The results showed that the random forest model yielded the best performance, resulting in an overall accuracy of 82.3%. The cross-site validation to examine the spatiotemporal transferability of the machine learning models showed that the models were highly sensitive to temporal differences between the training and validation sites, especially in the early growing season. This implies that a more robust model with high spatiotemporal transferability can be developed when more wildfire cases with different seasons and areas are added in the future.

• Journal of Korean Society of Forest Science
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• v.105 no.2
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• pp.167-176
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• 2016

This study was carried out to compare soil physicochemical properties and nutrient concentrations of tree leaf between planted forests following forest fire and an undisturbed forest in the Bongdaesan mountain, where is located in the Ulsan metropolitan city. We established three deciduous tree planting (Liriodendron tulipifera L., Prunus yedoensis Matsum and Quercus acutissima Carruth.) plots, one unplanted plot following four-year forest fire and one undisturbed plot (Pinus densiflora S et. Z). Carbon (C) stocks in the organic horizon were significantly lower in the tree planted plots ($2394-3551kg{\cdot}C{\cdot}ha^{-1}$) or the unplanted plots ($3689kg{\cdot}C{\cdot}ha^{-1}$) than in the undisturbed plot ($9388kg{\cdot}C{\cdot}ha^{-1}$). However, phosphorus (P), potassium (K) and magnesium (Mg) stocks in the organic horizon were not significantly different among the treatments. Soil water phase and soil pH were significantly higher in the P. yedoensis plot (water phase: 13.7-18.4%; soil pH: 4.62- 4.80) than in the undisturbed plots (water phase: 7.0%; soil pH: 4.10). Soil organic C concentration was slightly higher in the tree planted plots (1.89-3.60%) than in the unplanted (1.41%) plots. Soil Ca and Mg stocks at 10 cm of soil depth were significantly higher in the P. yedoensis and L. tulipifera plots than in the unplanted or undisturbed plots. Nutrient concentrations (Ca and Mg) of leaf were significantly higher in the L. tulipifera than in the Q. acutissima and the undisturbed pine plots. The results indicate that P, Ca, and Mg stocks in the organic horizon was not affected by tree planting, but Ca and Mg stocks at 10 cm of the soil depth were enhanced by the tree species established following four-year forest fire.