• 제목/요약/키워드: condition of vegetation

검색결과 462건 처리시간 0.023초

Change Analysis of Forest Area and Canopy Conditions in Kaesung, North Korea Using Landsat, SPOT and KOMPSAT Data

  • Lee, Kyu-Sung;Kim, Jeong-Hyun
    • 대한원격탐사학회지
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    • 제16권4호
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    • pp.327-338
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    • 2000
  • The forest conditions of North Korea has been a great concern since it was known to be closely related to many environmental problems of the disastrous flooding, soil erosion, and food shortage. To assess the long-term changes of forest area as well as the canopy conditions, several sources of multitemporal satellite data were applied to the study area near Kaesung. KOMPSAT-1 EOC data were overlaid with 1981 topographic map showing the boundaries of forest to assess the deforestation area. Delineation of the cleared forest was performed by both visual interpretation and unsupervised classification. For analyzing the change of forest canopy condition, multiple scenes of Landsat and SPOT data were selected. After preprocessing of the multitemporal satellite data, such as image registration and normalization, the normalized difference vegetation index (NDVI) was derived as a representation of forest canopy conditions. Although the panchromatic EOC data had radiometric limitation to classify diverse cover types, they can be effectively used t detect and delineate the deforested area. The results showed that a large portion of forest land has been cleared for the urban and agricultural uses during the last twenty years. It was also found that the canopy condition of remaining forests has not been improved for the last twenty years. It was also found that the canopy condition of remaining forests has not been improved for the last twenty years. Possible causes of the deforestation and the temporal pattern of canopy conditions are discussed.

Sentinel-1 SAR 토양수분 산정 연구: 식생에 따른 토양수분 모의평가 (Estimation of soil moisture based on Sentinel-1 SAR data: Assessment of soil moisture estimation in different vegetation condition)

  • 조성근;정재환;이슬찬;최민하
    • 한국수자원학회논문집
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    • 제54권2호
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    • pp.81-91
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    • 2021
  • Synthetic Aperture Radar (SAR)를 활용하여 토양수분을 산출 할 시 기존의 위성기반 자료에 비해 고해상도의 공간 자료를 생산할 수 있다. 고해상도의 광역 토양수분 자료는 기존의 위성 기반 토양수분 대비 보다 세밀한 지표면 토양수분 변동 관측이 가능하게 하므로, 산사태, 산불 및 홍수와 같은 자연재해 연구에 활용성이 뛰어나다. 하지만 SAR 신호인 후방산란계수는 토양수분 뿐만 아니라, 식생에 의한 영향도 포함하기 때문에 정확한 토양수분을 산정하기 위해서는 이러한 영향을 고려하는 단계가 요구된다. 본 연구에서는 한반도 중부의 농지, 산지, 및 초지의 식생조건 하에서 Sentinel-1 위성 SAR 자료를 활용하여 토양수분을 산정하기 위한 연구를 수행하였다. 식생의 영향을 고려하기 위해 대표적인 지표면 레이더 신호 산란 모형인 Water Cloud Model (WCM)을 사용하였으며, 식생 인자로 Radar Vegetation Index (RVI)를 활용하였다. 연구 지역으로는 토지피복도에 따라 농지와 초지, 산지 각각 2개 지역, 총 6개 대상 지역을 선정하였다. WCM의 매개변수 모의를 위해 지상 관측 토양수분 자료를 활용하였다. 관측 토양수분과의 검증 결과 초지, 산지, 농지 순으로 높은 정확도가 나타났으며, 특히 산지에서는 짙은 식생에도 불구하고 상관계수 값이 0.5 이상으로 나타난 반면 농지에서는 0.3 미만의 매우 낮은 값이 관측되었다. 연구 결과를 통해 다양한 식생 피복에서 SAR 기반 토양수분 산정에 적합한 관측 토양수분 조건을 제시 하였다. 향후 식생 높이, 식생 종류 등 과 융합한 연구가 수행된다면 보다 정확한 토양수분을 산정 할 수 있을 것으로 판단된다.

우리나라 중소도시 비오톱 공간의 조성방안 (The Potential Assessment and Creation Programming of Biotopes in Small and Medium City in Korea)

  • 정문선;이명우
    • 한국조경학회지
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    • 제28권4호
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    • pp.75-90
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    • 2000
  • This study suggests the methods of the assessment and creation of biotopes in small and medium sized cities, in Korea. For this purpose, Chonju city was selected to classify and asses the biotope types. Moreover, relevant legislations to conserve and enhance urban biotopes were examined. The results of this study are as follows: 1) There were two approaches to asses the potential of urban biotopes in medium-sized cities. One was the urban scale evaluation for urban green spaces and the other was the biotope scale evaluation for the classification and evaluation of biotopes. 2) The urban scale evaluation was developed through overlaping analysis of landuse and vegetation factors. This study also included the conception of watershed. In this conception, three watersheds in Chonju city were characterized. According to these characteristics, individual programs for conservation and enhancement of urban green space were suggested. 3) For the biotope scale evaluation, Selected site was inclusively mapped and field investigation actually was carried. There were total 9 types of bitopes. Especially landuse was appeared in various evaluation items were vegetation structure, area of green space, condition of vegetation and vegetation profile. Mt, Gonji and Dukjin park, Chonbuk national University and fields were evaluated highly I the potential. 4) The biotope programs were based on the results of assessment and physical characteristics of biotopes. The uniform and simple levels on vegetation must be modified with various levels of vegetation structure and vernacular plants. And the physical characteristics like Points, Corridors and Patches can be organized by the conception of biotope networking theory. 5) The proper legislative environment was the clue elements for the biotope programs. Until now, only five types of parks and two types of green space are defined and the minimum size of green space has been proposed by the law. So, it is necessary to enlarge the conception of green space in legislation and improve the quality of green space by amending the related regulations. This study has limitation because it was selected only in Chonju. Through the continuous studies, we need to apply this other small and medium sized cities, South Korea. Also the data collection and management of theme maps such as actual vegetation, landuse and a soil must be done preliminary.

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금정산성 주변 식생의 생태적 특성과 복원방안 (Restoration Plan and Ecological Characteristics of Vegetation in the Area Adjacent to GeumJeong Mountain Fortress)

  • 김석규
    • 환경영향평가
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    • 제19권3호
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    • pp.231-245
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    • 2010
  • The the purpose of this study was to analyze of the vegetation structure and phytosociological changes in the area adjacent to GeumJeong Mountain Fortress for fifteen years. The result of this study was as follows; Of the 8 quadrates, site of the North Gate 2 was having a highest in the number of extinct trees, 15 kinds. This is probably due to trampling effect caused by climbers' steps. Site of the West Gate 1 and South gate 1 each had 8 kinds of extinct trees, respectively. The number of newly appeared trees was highest at site of the North Gate 1, (8 kinds) followed by the sites of South gate 1 and South gate 2, respectively (5 kinds). The highest decrease in number of tree species was observed in North Gate 1, therefore, there is a strong relationship between vegetation diversity and the number of users of the available spaces. In order to revitalize the unstable vegetation structure of the Area Adjacent to GeumJeong Mountain Fortress, Robinia pseudo-acacia has to be well maintained in the shrub tree layer, and vines, such as Smilax china, Humulus japonicus, and Pueraria thungergiana, should be removed. To recover natural vegetation, dead leaf layer should be protected, and more shrub trees need to be planted. In the understory and shrub tree layer, multi layer tree planting is highly recommended to recover natural vegetation and increase tree diversity. In order to improve bad soil condition caused by trampling effect of recreational users, special treatments to the soil structure are required, such as mulching and raking soil. Also, depending on its soil damage from users trampling, the areas in the park should be divided into usable areas and user limited areas by the sabbatical year system. To improve the soil acidity due to acidic rain, soil buffering ability should be improved by activating microorganisms in the soil by using lime and organic material.

난지도 안정화공사 이후 생태계 복원을 위한 현존식생에 관한 연구 (A Study on the Actual Vegetation of Nanji-do for Restoration of Ecosystem after Stabilization Construction)

  • 이경재;오충현;김지석
    • 한국환경생태학회지
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    • 제11권1호
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    • pp.126-132
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    • 1997
  • 난지도는 서울외곽의 한강변에 위치한 면적 272ha인 섬으로, 1978년부터 1993년까지 약 15년간 서울지역에서 발생하는 각종 쓰레기 92,000,000m$^{2}$를 매립한 곳이다. 1996년 10월 현재 난지도의 현존식생면적은 191ha로서 이중 목본식물은 31ha이고 나머지는 초본식물이 우점종인 군락이었다. 목본식물 면적 중 아까시나무와 능수버들은 전체의 83%를 차지하고 있었다. 토양은 서울지역의 일반적인 토양이 산성으로 나타나는 것과는 달리 알카리성이며, 토양과 현존식생분포사이의 상관관계는 없는 것으로 나타났다. 연구 결과 난지도의 현존식생은 난지도 토양 안정화공사 이후의 식생목원지침 마련에는 도움이 되지 않을 것으로 나타났으므로 앞으로의 생태계 복원을 위해서는 다음과 같은 시도가 있어야 할 것이다. 첫째, 다양한 선구수종, 자생수종, 식이식물의 활착실험을 통해 난지도에 적합한 수종 선발. 둘째, 자생수종을 활용한 사면안정 공법의 개발 및 지역 특성에 적합한 식재계획 마련. 셋째, 동물 생태계 조사를 통한 동물생태계 복원계획 수립

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제주도 내륙습지 미나리못의 식생 형성과 물환경과의 관계 (Formation of Vegetation in an Inland Wetland, Minarimot, of Jeju Islands, and its Relationship to Water Environment)

  • 김명현;한민수;방혜선;정명표;나영은
    • 한국환경농학회지
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    • 제28권4호
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    • pp.365-370
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    • 2009
  • The aim of this study was to investigate the vegetation types of Minarimot, in Jeju Islands. The vegetation types were classified by the Z-M school method and cluster analysis. The vegetation in Minarimot was classified into 6 communities and 2 subcommunities: Persicaria thunbergii-Isachne globosa community (vegetation type: A), Scirpus tribangulatus-Eleocharis manillata var. cyclocarpa community (B) (Aneilema keisak subcommunity (B-1) and Caldesia parnassifolia-Potamogeton distinctus subcommunity (B-2)), Eleocharis kuroguwai community (C), Phragmites communis community (D), Scirpus tabernaemontani community(E) and Typha orientalis community (F). These communities were grouped into three main categories according to cluster analysis. The community (A) established at the edge of the wetland which has the driest condition was distinguished as Group I, while the community (B) emerged in the submerged zone was distinguished as Group III. The Group II was designated as the communities (C, D, E, F) between Group I and III, whose communities were occasionally submerged. The result of principal coordinate analysis (PCoA) appeared that the different vegetation established along the wetland were depending on water environment such as water depth and the period submerged.

Analysis of Changes in NDVI Annual Cycle Models Caused by Forest Fire in Yangyang-gun, Gangwon-do Using Time Series of Landsat Images

  • Choi, Yoon Jo;Cho, Han Jin;Hong, Seung Hwan;Lee, Su Jin;Sohn, Hong Gyoo
    • 대한공간정보학회지
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    • 제24권4호
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    • pp.3-11
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    • 2016
  • Sixty four percent of Korean territory consists of forest which is fragile for forest fire. However, it is difficult to detect the disaster-induced damages due to topographic complexity in mountainous areas and harsh weather conditions. For this reason, satellite imaging systems have been widely utilized to detect the damage caused by forest fire. In particular, ground vegetation condition can be estimated from multi-spectral satellite images and change detection technique has been used to detect forest fire damages. However, since Korea has clear four seasons, simple change detection technique has limitation. In this regard, this study applied the NDVI(normalized difference vegetation index) annual cycle modeling technique on time-series of Landsat images from 1991 to 2007 to analyze influence of forest fire of Yangyang-gun, Gangwon-do in 2005 on vegetation condition. The encouraging result was obtained when comparing the areas where forest fire occurs with non-damaged areas. The mean value of NDVI was decreased by 0.07 before and after the forest fire. On the other hand, annual variability of NDVI had been increasing and peak value of NDVI was stationary after the forest fire. It is interpreted that understory vegetation was seriously damaged from the forest fire occurred in 2005.

Phyto-Sociological Study of Resource Plant in Mt. Daedun

  • Lee, Yoon-Won
    • Plant Resources
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    • 제2권2호
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    • pp.113-126
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    • 1999
  • Through the research of tracheophytes type around Mt. Daedun, we are aiming at figuring out the habitat condition of useful resource plants by the classification of vegetation units and communities using the Z-M phyto-sociological method in the basis of the traits of species composition and by the analysis of vegetation and environment by way of coincidence method. Tracheophytes in our research sites was classifid into 117 family, 475 genus 797, species 102 variety,18 breed, in total to 917 kinds. The forest around Mt. Daedun district was classified into 6 communities, 12 groups, 2 sub-groups according to feature species group, differential species group and differential. Judging the result from the examination of community classification factors by the coincidence method, vegetation unit was decided by altitude and topography.

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소석회를 이용한 급경사 농경지 토양유실 저감 (Reduction of Soil Loss from Sloped Agricultural Field by using Hydrated Lime)

  • 고일하;유찬;박미정;지원현
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제24권2호
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    • pp.1-7
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    • 2019
  • The feasibility of using hydrated lime ($Ca(OH)_2$) was assessed in reducing soil loss in sloped land under field condition. During 6-month monitoring from May to October, amendment of hydrated lime (3%, w/w) to a test plot decreased soil loss by 76% as compared to the unamended plot. However, the growth of natural vegetation was hampered by hydrated lime addition due to pH increase. Hydrated lime can be used as an effective agent to prevent soil loss in sloped land, but additional treatments are needed to preserve vegetation growth, especially in crop fields.

일체형 식생호안블록 시스템 개발 및 수리특성 연구(I) -일체형 호안블록 개발 및 수리모형실험을 통한 적용성 검토- (Development and Hydraulic Characteristics of Continuous Block System in River Bank Protection (I) - Development and Application Review through Hydraulic Model Test -)

  • 장석환
    • 한국습지학회지
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    • 제10권3호
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    • pp.87-97
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    • 2008
  • 본 연구는 현재 대부분의 자연형 하천에 적용되는 프리캐스트 호안블록 대신 현장 타설식 일체형 블록시스템을 개발하고 수리특성분석을 위하여 수리모형 실험을 실시하여 수위와 유속의 변화를 통하여 호안 적용성을 검토하였다. 기존의 프리캐스트 불록은 홍수 시 빠른 유속과 집중하중에 유실 및 탈락의 문제점이 나타나고 있으나 이를 보완한 일체형 호안블록 시스템은 홍수시나 수충부에 적합한 호안식생블록 시스템이다. 수리모형실험에서는 성덕댐이 위치한 보현천의 하도에 1/50 축척으로 모형을 재현하고 설계홍수량을 방류하는 조건으로 하도에서 원형과 개발된 블록의 식생유무에 대한 흐름 및 특성의 변화를 검토하였다. 검토결과, 설계홍수량 $200m^3/sec$에서 유속 저감 평균 10.1%, 수위 상승 평균 17.8%의 실험 결과를 얻었다. 연구(II)에서는 수치모형실험을 통하여 실험결과를 검증하고자 하였다.

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