• Title/Summary/Keyword: FORESTED AREAS

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Applicability of Supervised Classification for Subdividing Forested Areas Using SPOT-5 and KOMPSAT-2 Data (산림지역 분류를 위한 SPOT-5 및 KOMPSAT-2 영상의 감독분류 적용성)

  • Choi, Jaeyong;Lee, Sanghyuk;Lee, Sol Ae;Ji, Seung Yong;Lee, Peter Sang-Hoon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.18 no.2
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    • pp.89-104
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    • 2015
  • In order to effectively manage forested areas in South Korea on a national scale, using remotely sensed data is considered most suitable. In this study, utilizing Land coverage maps and Forest type maps of national geographic information instead of collecting field data was tested for conducting supervised classification on SPOT-5 and KOMPSAT-2 imagery focusing on forested areas. Supervised classification were conducted in two ways: analysing a whole area around the study site and/or only forested areas around the study site, using Support Vector Machine. The overall accuracy for the classification on the whole area ranged from 54.9% to 68.9% with kappa coefficients of over 0.4, which meant the supervised classification was in general considered moderate because of sub-classifying forested areas into three categories (i.e. hardwood, conifer, mixed forests). Compared to this, the overall accuracy for forested areas were better for sub-classification of forested areas probably due to less distraction in the classification. To further improve the overall accuracy, it is needed to gain individual imagery rather than mosaic imagery to use more spetral bands and select more suitable conditions such as seasonal timing. It is also necessary to obtain precise and accurate training data for sub-classifying forested areas. This new approach can be considered as a basis of developing an excellent analysis manner for understanding and managing forest landscape.

Extractable Micronutrients in Soils of Some Forested and Deforested Sites of South Eastern Hilly Areas of Bangladesh

  • Akhtaruzzaman, Md.;Osman, K.T.;Haque, S.M. Sirajul
    • Journal of Forest and Environmental Science
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    • v.34 no.6
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    • pp.429-434
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    • 2018
  • Extractable iron (Fe), manganese (Mn), zinc (Zn) and copper (Cu) contents and their distribution with depths in soils of forested and adjacent deforested areas at Jahazpura, Teknaf, Cox's Bazar of Bangladesh were studied. The soils under forest showed higher levels of DTPA-extractable micronutrients in all three layers of soil in comparison to those of the deforested areas. The differences between forested and deforested sites were, in most cases, significant.. The top soils of forested sites had the higher contents of micronutrient and generally decreased with depth in forested soils, while there was no regular trend of distribution in deforested soils. The study also revealed that contents of extractable Fe, Mn and Cu were sufficient in all depths and sites but Zn was deficient in bottom layer of forested and all three layers of deforested sites. The results suggested that organic matter, clay and soil pH could play important roles in concentrations and distributions of micronutrients in soils of the study areas.

Comparing the Current Health Status and Health Behaviors of Residents from Urban and Forested Areas (산림 지역과 도시 지역 성인의 건강상태 및 건강행태 비교)

  • Lee, Insook;Lee, Kowoon;Kim, Sung Jae;Bang, Kyung Sook;Choi, Hee Seung
    • Perspectives in Nursing Science
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    • v.12 no.1
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    • pp.14-22
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    • 2015
  • Purpose: Forests have positive effects on health due to phytoncide, thus increasing physical activity and stress relief. However, research has not been conducted on the daily health benefits of existing forests. Therefore, this study attempts to compare the health status and behaviors of residents in urban and forested areas. Methods: This cross-sectional study used anthropometric measures, blood tests, heart rate variability, depression, stress, and health behavior self-reports for adults between 35 and 79 years from two regions. Results: Adults living in a forested region had better health consequences-including lower prevalence of osteoarthritis (6.4%) and mean bone mineral density (-0.84) -than those in an urban region (osteoarthritis: 13.7%; bone mineral density: -1.55). The percentage of 'physically active' participants (measured in MET-minutes) differed significantly different between the forested (49.1%) and urban (7.3%) areas. However, health behaviors such as smoking, alcohol consumption, and regular heath check-up rates were worse among residents from the forested, than the urban area. Conclusion: We concluded that more proactive forest therapy programs are needed to prove the health differences.

Monitoring Deforestation in Kenya

  • Ngigi, Thomas G;Tateishi, Ryutaro
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.244-247
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    • 2003
  • Multi-temporal data is used to determine the rate of deforestation between the years 1976, 1987 and 2000. Three Landsat TM images, for each period, are pre-processed, mosaicked and normalized difference vegetation index (NDVI) values computed. Based on the values, totally non-forested areas are masked out. The forested areas, both partially and wholly, show a very high degree of correlation between all the bands (reflective), thus necessitating application of principal component analysis. The first two principal components and NDVI values (scaled to 0 ? 255) are used in K-means unsupervised classification to distinguish forest from non-forest areas (that appeared as forest at first). Comparison of the resulting thematic maps gives an annual deforestation rate of roughly 15 0000ha. or 2% between any two epochs.

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Environmental Change of Suspended Sediment Discharge by Human Action (인간활동으로 인한 부유토양유출의 환경변화)

  • 박종관
    • Journal of Environmental Science International
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    • v.2 no.2
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    • pp.153-160
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    • 1993
  • The problem of supply and transport of sediment from a mountainous catchment is very important in explaining dynamic geomorphology and the hydrological cycle. The discharge of suspended sediment is determined by a morphological system. Human interference to environment Is also an important, not negligible factor in sediment production. Moreover, growing concern in recent years for the problems of nonpoint pollution and for the transport of contaminants through terrestrial and aquatic ecosystems has highlighted the role of sediment-associated transport in fluvial systems. This study was conducted in forested and quarried catchments in order to clarify the different discharge process and the mechanism of suspended sediment dynamics for each catchment. As a forested catchment, the Yamaguchi River catchment which drains a $3.12km^2$ area was chosen. On the other hand, the Futagami River basin which is formed by three subbasins (1.07, 1.59 and $1.78km^2$), as a quarried catchment was selected. These catchments are situated to the north and east of Mt. Tsukuba, Ibaraki, Japan. The discharge pattern of suspended sediment from the Futagami River basin is more unstable and irregular than that from forested catchment, the Yamaguchi River catchment. Under the similar rainstorm conditions, suspended sediment concentration from quarried catchment during a rainstorm event increases from 43 to 27,340 mg/l. However, in the case of the forested catchment it changes only from nearly zero to 274 mg/l. Generally, the supply source of suspended sediment is classified into two areas, the in-channel and non-channel source areas. As a result of field measurements, in the case of the forested catchment the in-channel (channel bed, channel bank and channel margin) is the main source area of suspended sediment. On the other hand, remarkable sediment source area on the Quarried catchment is the non-channel that is unvegetated ground.

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Diets and Foraging Tactics of Eurasian Eagle Owls(Bubo bubo) in Two Different Habitat Types (서로 다른 환경에서 서식하는 수리부엉이(Bubo bubo)의 먹이 이용)

  • Nam, Hyun-Young;Lee, Woo-Shin;Choi, Chang-Yong
    • Korean Journal of Environment and Ecology
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    • v.21 no.1
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    • pp.30-37
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    • 2007
  • Pellets and prey remains were analyzed to compare diets and foraging tactics of Eurasian eagle owls (Bubo bubo) in two different habitat types: forested areas and open fields. Overall 150 prey items of three taxa were identified from 66 pellets and 82 prey remains, and the birds were the most important prey in biomass (78.04%) and in frequency (56.67%). Eurasian eagle owls frequently used rats (Rattus spp.), ring-necked pheasants (Phasianus colchicus), and stripped field mice (Apodemus agrarius), but the ring-necked pheasant was most important in biomass in both habitat types. The owls generally foraged various prey in biomass but the mean mass of vertebrate prey used by the Eurasian eagle owls was 503.3g in central Korea. According to the comparison of diets in the two different habitat types, the owls used bigger and more diverse prey in forested areas than in open fields. In forested areas, the Eurasian eagle owls frequently foraged the pheasants and Mandarin ducks (Aix galericulata), but they preferred prey of particular sizes to prey of particular taxa. In open fields, however, the owls showed opportunistic foraging tactics by selecting many small mammals such as rodents or a few large birds.

Morphological Characteristics of Forested Coastal Dune Areas Using Direct Topographic Surveys: A Case Study in Dasari, Chungnam (해안림 내부의 지형측량을 통한 충남 다사리 해안사구의 형태적 특징)

  • Choi, Kwang Hee;Kim, Jang soo;Kong, Hak-Yang
    • Journal of The Geomorphological Association of Korea
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    • v.24 no.1
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    • pp.1-12
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    • 2017
  • Planting trees is a very common practice in the coastal dunefields of South Korea as a way to stabilize dune landscapes and protect inland residential areas from strong winds and blown sands. On the other hand, disturbing the original foredune environment may deteriorate the ability of coastal landsto recover from coastal erosion after storms, causing a retreat of coastline. However, there is little information of this sort on the surface of forested dunefields. Airborne LiDAR or drone-based mapping is not easily applicable in such areas. In this study, we developed a digital terrain model of Dasari dunefields, Chungnam Province, based on direct topographic surveys with real-time kinematic GPS and total stations. We also analyzed previous two aerial photographs taken in 1947 and 1966, in order to detect an older landforms of the dunefields. Results suggested that there have been little changes in geomorphology of the Dasari dunefields for the last 50 years, despite continued tree plantings. Today, there are remains of U-shaped structures such as blowouts and parabolic dunes in the dunefields.

A Comparison of the Impact of Regional Anthropogenic Climatic Change in Urban and Rural Areas in South Korea (1955-2016) (최근 60년간 도시 및 농촌 지역의 국지적 기후변화 비교 분석)

  • Yoon, Dong-Hyun;Nam, Won-Ho;Hong, Eun-Mi;Kim, Taegon;Ho, Chang-Hoi;Hayes, Michael J.
    • Journal of The Korean Society of Agricultural Engineers
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    • v.60 no.3
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    • pp.37-50
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    • 2018
  • Local climate characteristics for both urban and rural areas can be attributed to multiple factors. Two factors affecting these characteristics include: 1) greenhouse gases related to global warming, and 2) urban heat island (UHI) effects caused by changes in surface land use and energy balances related to rapid urbanization. Because of the unique hydrological and climatological characteristics of cities compared with rural and forested areas, distinguishing the impacts of global warming urbanization is important. In this study, we analyzed anthropogenic climatic changes caused by rapid urbanization. Weather elements (maximum temperature, minimum temperature, and precipitation) over the last 60 years (1955-2016) are compared in urban areas (Seoul, Incheon, Pohang, Daegu, Jeonju, Ulsan, Gwangju, Busan) and rural/forested areas (Gangneung, Chupungnyeong, Mokpo, and Yeosu). Temperature differences between these areas reveal the effects of urbanization and global warming. The findings of this study can be used to analyze and forecast the impacts of climate change and urbanization in other urban and non-urban areas.

A Comparison between Wet-only and Bulk Deposition at Two Forest Sites in Japan

  • Imamura, Naohiro;Iwai, Noriko;Tanaka, Nobuaki;Ohte, Nobuhito
    • Asian Journal of Atmospheric Environment
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    • v.12 no.1
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    • pp.67-77
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    • 2018
  • To investigate the effects of forest and the surrounding natural and anthropogenic sources on the bulk depositions on forested land, this study examined differences in ion concentrations between wet-only and bulk samples at two forested sites in Japan. The surrounding natural and anthropogenic sources at each site were different; Shirasaka is in a rural area and Tanashi is an urban environment. The volume weighted (vw) mean concentrations of $K^+$ and $Ca^{2+}$ in the bulk samples were significantly (p<0.05) higher than those in the wet-only samples at both sites. The forest canopy and a nearby incineration plant were hypothesized to be the main sources of $K^+$ contaminants at Shirasaka and Tanashi, respectively. The transport of sea salt and urban dust may explain the presence of enriched $Ca^{2+}$ concentrations in the bulk samples at Shirasaka and Tanashi, respectively. The $NH_4{^+}$ concentrations in the Shirasaka bulk samples were significantly (p<0.05) lower than those in the wet-only samples. The vw mean $SO{_4}^{2-}$ and $NO_3{^-}$ concentrations in both sample types were not significantly different at either site. This study demonstrated that the ion concentration differences between wet-only and bulk samples were affected by nearby natural and anthropogenic sources even at forest sites, similar to previous findings for non-forested locations. However, the $K^+$ concentration differences between wet-only and bulk samples may be higher owing to forest sources, even in the absence of anthropogenic sources.

GeoAI-Based Forest Fire Susceptibility Assessment with Integration of Forest and Soil Digital Map Data

  • Kounghoon Nam;Jong-Tae Kim;Chang-Ju Lee;Gyo-Cheol Jeong
    • The Journal of Engineering Geology
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    • v.34 no.1
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    • pp.107-115
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    • 2024
  • This study assesses forest fire susceptibility in Gangwon-do, South Korea, which hosts the largest forested area in the nation and constitutes ~21% of the country's forested land. With 81% of its terrain forested, Gangwon-do is particularly susceptible to wildfires, as evidenced by the fact that seven out of the ten most extensive wildfires in Korea have occurred in this region, with significant ecological and economic implications. Here, we analyze 480 historical wildfire occurrences in Gangwon-do between 2003 and 2019 using 17 predictor variables of wildfire occurrence. We utilized three machine learning algorithms—random forest, logistic regression, and support vector machine—to construct wildfire susceptibility prediction models and identify the best-performing model for Gangwon-do. Forest and soil map data were integrated as important indicators of wildfire susceptibility and enhanced the precision of the three models in identifying areas at high risk of wildfires. Of the three models examined, the random forest model showed the best predictive performance, with an area-under-the-curve value of 0.936. The findings of this study, especially the maps generated by the models, are expected to offer important guidance to local governments in formulating effective management and conservation strategies. These strategies aim to ensure the sustainable preservation of forest resources and to enhance the well-being of communities situated in areas adjacent to forests. Furthermore, the outcomes of this study are anticipated to contribute to the safeguarding of forest resources and biodiversity and to the development of comprehensive plans for forest resource protection, biodiversity conservation, and environmental management.