• Title/Summary/Keyword: forest fragmentation

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Development and Application of Impact Assessment Model of Forest Vegetation by Land Developments (개발사업에 따른 산림식생 영향평가모형 개발 및 적용)

  • Lee, Dong-Kun;Kim, Eun-Young
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.12 no.6
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    • pp.123-130
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    • 2009
  • Fragmentation due to land developments causes disturbances and changes of composition in forest vegetation. The purpose of the study was to develop the impact assessment model for quantitative distance or degree of disturbance by land developments. This study conducted a survey about structure and composition of forest vegetation to determine degree of impact from land developments. The results of field survey, there was a difference in structure and composition of forest vegetation such as tree canopy, herbaceous cover, and number of vine and alien species the distances from edge to interior area such as 0m, 10m, 20m, 40m, and over 60m. To assess the disturbance of forest vegetation, the factors selected were the rate of vine's cover and appearance of alien species. The impact assessment model about vine species explained by a distance, forest patch size, type of forest fragmentation, and type of vegetation ($R^2$=0.44, p<0.001). The other model about alien species explained by a distance, type of forest fragmentation, type of vegetation, and width of road (85.9%, p<0.005). The models applied to Samsong housing development in Goyang-si, Gyunggi-do. The vines and alien species in the study area have had a substantial impact on forest vegetation from edge to 20 or 40m. The impact assessment models were high reliability for estimating impacts to land developments. The impact of forest vegetation by development activities could be minimized thorough the adoption of the models introduced at the stage of EIA.

Impact Assessment Model of Bird Species for Land Developments (개발사업에 따른 조류종 영향평가모형 개발 및 적용)

  • Lee, Dong-Kun;Kim, Eun-Young;Lee, Eun-Jae;Song, Won-Kyong
    • Journal of Environmental Impact Assessment
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    • v.19 no.3
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    • pp.347-356
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    • 2010
  • Forests are being seriously fragmented as a result of land development. Land development with disregard to its subsequent environmental impacts is a primary threat to biodiversity by incurring massive habitat losses and changes in structure and composition of forests. The purpose of this study was to develop the impact assessment model for quantitative distance or degree of disturbance by land developments. This study conducted a survey about structure and composition of forest species to determine degree of impact from land development. The edge effect of forest fragmentation on the number of bird species, population size, and bird diversity was obvious. In particular, the bird diversity sharply declines around the forest edge where intensive land development projects take place. To assess the disturbance of forest species, the factors selected were the bird diversity and the rate of edge species. The impact assessment model about bird diversity was explained by type of forest fragmentation and type of vegetation ($R^2$=0.23, p<0.005). The other model about edge species explained by a distance, type of forest fragmentation, type of vegetation, and width of road ($R^2$=0.34, p<0.001). In order to test the applicability of the model developed in this study, the models was applied to the Samsong housing development in Goyang-si, Gyunggi-do. The impacts of land development on the bird species were reasonably quantified to suggest effective mitigation measure. The impact assessment model developed in this study is useful to assess the magnitude of disturbance of bird species. Particularly, the model could be applied to the current Environmental Impact Assessment practices to predict and quantify the impacts of land developments projects on forest bird species.

Evaluation of Water Quality Impacts of Forest Fragmentation at Doam-Dam Watershed using GIS-based Modeling System (GIS 기반의 모형을 이용한 도암댐 유역의 산림 파편화에 따른 수(水)환경 영향 평가)

  • Heo, Sung-Gu;Kim, Ki-Sung;Ahn, Jae-Hun;Yoon, Jong-Suk;Lim, Kyoungjae;Choi, Joongdae;Shin, Yong-Chul;Lyou, Chang-Won
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.4
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    • pp.81-94
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    • 2006
  • The water quality impacts of forest fragmentation at the Doam-dam watershed were evaluated in this study. For this ends, the watershed scale model, Soil and Water Assessment Tool (SWAT) model was utilized. To exclude the effects of different magnitude and patterns in weather, the same weather data of 1985 was used because of significant differences in precipitation in year 1985 and 2000. The water quality impacts of forest fragmentation were analyzed temporarily and spatially because of its nature. The flow rates for Winter and Spring has increased with forest fragmentations by $8,366m^3/month$ and $72,763m^3/month$ in the S1 subwatershed, experiencing the most forest fragmentation within the Doam-dam watershed. For Summer and Fall, the flow rate has increased by $149,901m^3/month$ and $107,109m^3/month$, respectively. It is believed that increased flow rates contributed significant amounts of soil erosion and diffused nonpoint source pollutants into the receiving water bodies. With the forest fragmentation in the S1 watershed, the average sediment concentration values for Winter and Spring increased by 5.448mg/L and 13.354mg/L, respectively. It is believed that the agricultural area, which were forest before the forest fragmentation, are responsible for increased soil erosion and sediment yield during the spring thaw and snow melts. For Spring and Fall, the sediment concentration values increased by 20.680mg/L and 24.680mg/L, respectively. Compared with Winter and Spring, the increased precipitation during Summer and Fall contributed more soil erosion and increased sediment concentration value in the stream. Based on the results obtained from the analysis performed in this study, the stream flow and sediment concentration values has increased with forest fragmentation within the S1 subwatershed. These increased flow and soil erosion could contribute the eutrophication in the receiving water bodies. This results show that natural functionalities of the forest, such as flood control, soil erosion protection, and water quality improvement, can be easily lost with on-going forest fragmentation within the watershed. Thus, the minimize the negative impacts of forest fragmentation, comprehensive land use planning at watershed scale needs to be developed and implemented based on the results obtained in this research.

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Land cover change and forest fragmentation analysis for Naypyidaw, Myanmar (미얀마 네피도 지역의 도시개발로 인한 토지피복변화 탐지 및 산림파편화 분석)

  • Kong, In-Hye;Baek, Gyoung-Hye;Lee, Dong-Kun
    • Journal of Environmental Impact Assessment
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    • v.22 no.2
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    • pp.147-156
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    • 2013
  • Myanmar(Burma) has been preserved valuable environmental resources because of its political isolation. But recently, Myanmar has moved a capital city(Naypyidaw) at central forest area and it has been urbanized radically since 2005. In this paper, we built multi-temporal land cover map from Landsat images of 1970s to 2012 with ENVI 4.5 software. For a broad approach, administrative district Yamethin which includes Naypyidaw is classified into 3 classes and with only Naypyidaw region is classified with 4-5 classes to analyse specific changes. And with forest cover extracted by Object Oriented Classification, we evaluated forest fragmentation before and after the development using Patch Analyst(FRAGSTATs 3.3) at Yamethin area. For Yamethin area, there were significant forest cover change, 51% in 1999 to 48% in 2012, and for Naypyidaw area, 67% in 1999 to 57% in 2012 respectively. Also landscape indices resulted from Patch Analyst concluded that the total edge, edge density and mean shaped index of forest patches increased and total core area is decreased. It is attributed from land cover change with urbanization and agricultural land expansion.

Patterns of Forest Landscape Structure due to Landcover Change in the Nakdong River Basin (토지이용변화에 따른 낙동강 유역 산림경관의 구조적 패턴 분석)

  • Park, Kyung-Hun;Jung, Sung-Gwan;Kwon, Jin-O;Oh, Jeong-Hak
    • Journal of Korean Society of Rural Planning
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    • v.11 no.4 s.29
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    • pp.47-57
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    • 2005
  • The goal of this research is to evaluate landscape-ecological characteristics of watersheds in the Nakdong River Basin by using Geogaphic Information System (GIS) and landscape indices for integation of spatio-temporal informations and multivariate statistical techniques for quantitative analysis of forest landscape. Fragmentation index and change matrix techniques using factor analysis and grid overlay method were used to efficiently analyze and manage huge amount of information for ecological-environmental assessment (land-cover and forest landscape patterns). According to the results based on the pattern analysis of land-cover changes using the change detection matrix between 1980s and 1990s, addition on 750km$^2$ became urbanized areas. The altered 442.04km$^2$ was agricultural areas which is relatively easy for shifting of land-use, and 205.1km$^2$ of forests became urbanized areas, and average elevation and slope of the whole altered areas were 75m and 4$^{\circ}$. On the other hand, 120km$^2$ of urban areas were changed into other areas (i.e., agricultural areas and green space), and fortunately, certain amount of naturalness had been recovered. But still those agricultural areas and fallow areas, which were previously urban areas, had high potential of re-development for urbanization due to their local conditions. According to the structural analysis of forest landscape using the landscape indices, the forest fragmentation of watersheds along the main stream of the Nakdong River was more severe than my other watersheds. Furthermore, the Nakdong-sangju and Nakdong-miryang watersheds had unstable forest structures as well as least amount of forest quantity. Thus, these areas need significant amount of forest through a new forest management policy considering local environmental conditions.

Prediction of Fragmentation Impact Range of Forest Development Analyzing the Pattern of Landscape Indexes (경관지수 패턴 분석을 이용한 산지개발사업의 산림파편화 영향범위 예측)

  • Ji, Seung-yong;Choi, Jaeyong;Lee, Sang-hyuk;Lee, Peter Sang-Hoon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.19 no.2
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    • pp.109-119
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    • 2016
  • In South Korea the need of sustainably managing development on forest lands has required to develop a new approach to estimating environmental impacts on forest surrounding development sites in a scientific manner. As for forest-related development, two types of development were selected: golf courses and industrial complexes. Using Fragstats 4.2, the fragmentation effects and patterns of each type by forest area within project sites and buffer zones ranging from the outside of project sites up to 2,000 meters were analyzed. As a result, golf courses were strongly related to a group of fragmentation indexes: CA, NP, PD, TE, LSI, TCA, NDCA and CONNECT, whereas industrial complexes were associated with CA, NP, PD, TE, LSI and CONNECT. Among them, NP, LSI, TCA and NDCA of golf courses were considered as representative indexes reflecting the average impact ranges of each sub-group by forest area, and focussing on the size of core areas. In the case of industrial complexes, PD, TE and LSI were the representatives, vulnerable to the composition of given landscape. For two case studies, one for golf courses and the other for industrial complexes, they showed there existed a difference between the average of a group and the individual results. Therefore, to minimize the variations in impact range within a group, it is needed to analyze more individual cases. This study proved there was a distinction between project types in terms of the range of environmental impact. To effectively and comprehensively manage forest development, further research on analyzing other development types related to forests with more cases is needed.

A Study on the Improvement of Guideline in Digital Forest Type Map (수치임상도 작업매뉴얼의 개선방안에 관한 연구)

  • PARK, Jeong-Mook;DO, Mi-Ryung;SIM, Woo-Dam;LEE, Jung-Soo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.22 no.1
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    • pp.168-182
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    • 2019
  • The objectives of this study were to examine the production processes and methods of "Forest Type Map Actualization Production (Database (DB) Construction Work Manual)" (Work Manual) identify issues associated with the production processes and methods, and suggest solutions for them by applying evaluation items to a 1:5k digital forest type map. The evaluation items applied to a forest type map were divided into zoning and attributes, and the issues associated with the production processes and methods of Work Manual were derived through analyzing the characteristics of the stand structure and fragmentation by administrative districts. Korea is divided into five divisions, where one is set as the area changed naturally and the other four areas set as the area changed artificially. The area changed naturally has been updated every five years, and those changed artificially have been updated annually. The fragmentation of South Korea was analyzed in order to examine the consistency of the DB established for each region. The results showed that, in South Korea, the number of patches increased and the mean patch size decreased. As a result, the degree of fragmentation and the complexity of shapes increased. The degree of fragmentation and the complexity of shapes decreased in four regions out of 17 regions (metropolitan cities and provinces). The results indicated that there were spatial variations. The "Forest Classification" defines the minimum area of a zoning as 0.1ha. This study examined the criteria for the minimum area of a zoning by estimating the divided object (polygon unit) in a forest type map. The results of this study revealed that approximately 26% of objects were smaller than the minimum area of a zoning. The results implied that it would be necessary to establish the definition and the regeneration interval of "Areas Changed Artificially and Areas Changed Naturally", and improve the standard for the minimum area of a zoning. Among the attributes of Work Manual, "Species Change" item classifies terrain features into 52 types, and 43 types of them belong to stocking land. This study examined distribution ratios by extracting species information from the forest type map. It was found that each of 23 species, approximately 53% of species, occupied less than 0.1% of Forested land. The top three species were pine and other species. Although undergrowth on unstocked forest land are classified in the terrain feature system, their definition and classification criteria are not established in the "Forest Classification" item. Therefore, it will be needed to reestablish the terrain feature system and set the definitions of undergrowth.

A Temporal Structure Analysis of Forest Landscape Patterns using Landscape Indices in the Nakdong River Basin (경관지수를 활용한 낙동강 유역 산림경관의 시계열적 패턴 분석)

  • Jung, Sung-Gwan;Oh, Jeong-Hak;Park, Kyung-Hun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.8 no.2
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    • pp.145-156
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    • 2005
  • An artificial disturbance like forest fragmentation has affected the sustainability of forest ecosystem. Therefore, in order to manage the forest ecosystem efficiently needed to analyze quantity and quality (structural pattern) of forest simultaneously. This study analyzed the structural patterns of forest landscape to provide a basic data for evaluation and management of forest ecosystem in Nakdong River Basin during 10 years from 1980s to 1990s using landscape indices and GIS methods. Forest distribution maps and 6 landscape indices(LPI, PD, ED, MSI, CPLAND, IJI) for the analysis were reconstructed from land-cover maps constructed by Ministry of Environment and pearson correlation analysis. According to the structural analysis of forest landscape using landscape indices, the forest fragmentation of watersheds along the main stream of the Nakdong river was more severe than any other watersheds. Futhermore, the Nakong-sangju and Nakdong-miryang watersheds had unstable forest structures as well as least amount of forest quantity. Thus, these watersheds need significant amount of forest through a new forest management policy considering local environmental conditions. The connectivity between forests in local regions should be considered as well.

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Analysis of the Change in Pattern of Seoul Forest Patch to have used Landsat MSS Data (Landsat Mss Data를 이용한 서울시 산림패취의 패턴 변화분석)

  • Lee, Jong-Sung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.26 no.2
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    • pp.240-250
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    • 1998
  • This study is to have attempted to analyze the characteristics of the change in forest landscape pattern of Seoul for 18 years by grasping it through satellite image data on the forest area in Seoul where a rapid change according urbanization and industrialization is going on. On the basis of Landsat MSS data- satellite image data, this writer analyzed the change in the number and size of patch and the mean edge length of each forest land, and the index of patch shape by each year from a landscape -ecological point of view. The results are as follows; First, in the pattern change of the forest patch of Seoul, the highest patch fragmentation area is the forest of the Yangchon-gu district where is decreasing it forest area by 654ha, 511ha, 495ha, 402ha each year from its total size of 742ha in 1979. Second, the change tendency shows that the average forest size decreased at 552.58ha in 1983, 435.03ha in 1988, 396.23ha in 1992, and 379.96ha in 1996. And analysis showed that even in the number of patches, the forest fragmentation phenomenon was presenting by the increase of development disturbance. Third, the mean edge by year was longest at 23,385m in 1979, but it is decreasing continuously. This shows the regular and artificial uniformity of forest landscape by disturbance-effect increase of the built-up development and shows low portion against edge effect by the time-series change like 1979>1983>198>1992>1996. Finally, in the analysis of a shape index indicated by ratio of size and edge, total averages were 2.56, 2.33, 2.17, 2.14, 2.14 each year, so that it is considered that the disturbance and ecological health status against forest landscape can be grasped according to being examined as 1979>1983>1988>1992, 1996 by the time-series change of the landscape.

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