• Title/Summary/Keyword: Land-use/cover Change

Search Result 206, Processing Time 0.028 seconds

Urban Thermo-profiles and Community Structure of Quercus mongolica Forests along an Urban-rural Land Use Gradient: Implications for Management and Restoration of Urban Ecosystems

  • Cho, Yong-Chan;Cho, Hyun-Je;Lee, Chang-Seok
    • Journal of Ecology and Environment
    • /
    • v.32 no.3
    • /
    • pp.167-176
    • /
    • 2009
  • Land cover changes associated with urbanization have driven climate change and pollution, which alter properties of ecosystems at local, regional, and continental scales. Thus, the relationships among urban ecological variables such as community composition, structure, health, soil and functioning need to be better understood to restore and improve urban ecosystems. In this study, we discuss urban ecosystem management and research from a futuristic perspective based on analyses of vegetation structure, composition, and successional trends, as well as the chemical properties of soils and the distribution of heat along an urban-rural gradient. Urban thermo-profile analysis using satellite images showed an obvious mitigating effect of vegetation on the Seoul heat island. Community attributes of Quercus mongolica stands reflected the effects of urbanization, such as pronounced increases in disturbance-related and pollution-tolerant species, such as Styrax japonica and Sorbus alnifolia. Retrogressive successional trends were detected in urban sites relative to those in rural sites. Changes in the urban climate and biotic environment have the potential to significantly influence the practice and outcomes of ecological management, restoration and forecasting because of the associated changes in future bio-physical settings. Thus, for management (i.e., creation and restoration) of urban green spaces, forward-thinking perspectives supported by historical information are necessary.

The Changes of Meteorological Environment by Urban Development (대규모 도시 재개발에 따른 기상환경변화)

  • Kim, Geun-Hoi;Kim, Yeon-Hee;Koo, Hae-Jung;Kim, Kyu-Rang;Jung, Hyun-Sook
    • Atmosphere
    • /
    • v.24 no.1
    • /
    • pp.69-76
    • /
    • 2014
  • Urbanization affects the local thermal environment due to the large scale land use changes. To investigate the weather environment change of large scale urban redevelopment, 9 surface temperature and humidity observations were accomplished at Eunpyeong new town area. The observation period is from March 2007 to February 2010. In the center of development area, the air temperature has increased and relative humidity has decreased, by the changes of the land cover and building construction. In the area where the green zone is maintained, air temperature and relative humidity were not changed significantly. The air temperature and relative humidity for the other development observation stations is decreased and increased, respectively. The relative temperature difference between study area and a neighboring rural location was increased during observation periods. The difference is the highest during winter. The urban-rural minimum temperature difference was increased at development area, which means that urbanization affects increasing of minimum temperature in study area.

Application of the Modified CA-Markov Technique for Future Prediction of Forest Land Cover in a Mountainous Watershed (미래 산림식생변화 예측을 위한 개선된 CA-Markov 기법의 적용)

  • Park, Min-Ji;Park, Geun-Ae;Lee, Yong-Jun;Kim, Seong-Joon
    • Journal of The Korean Society of Agricultural Engineers
    • /
    • v.52 no.1
    • /
    • pp.61-68
    • /
    • 2010
  • 토지피복은 대부분의 수문 수질 모형의 중요한 매개변수로서, 수자원 변화 예측에 중요한 입력자료로 활용되고 있다. 본 연구에서는 개선된 CA (Cellular Automata)-Markov 기법을 이용하여 충주댐유역의 미래 산림식생변화에 대한 예측을 시도하였다. 예측과정으로 과거의 Landsat TM 영상 (1985, 1990, 1995, 2000)을 이용하여 기법의 정확도 검증 및 산림분포의 변화경향을 파악하고, Landsat 산림은 2000년과 2005년의 NOAA AVHRR NDVI값을 기준으로 침엽수림, 혼효림, 활엽수림의 3종으로 구분한 후, 이를 이용하여 2030년, 2060년, 2090년의 식생변화를 추정하는 방법을 제안하였다. 이 방법의 적용결과, 2000년과 비교하여 2090년의 활엽수림과 혼효림은 각각 14.3 %, 11.6 % 증가하였으며, 침엽수림은 24.9 % 감소하는 것으로 나타났다. 과거의 경향성에 의해 예측을 시도한 본 연구결과는 미래 토지피복 변화에 따른 수문 수질 영향 분석시 지표 조건의 불확실성을 줄이는데 활용될 수 있다고 판단된다.

A Study on the Environmental Changes of Coastal Area in Oncheon Gun of Pyeongnam Province by Neural Network Classification Using Satellite Images, West Coast of North Korea (위성영상의 신경망 분류에 의한 평안남도 온천군 해안지역의 환경 변화 연구)

  • Lee, Min-Boo;Kim, Nam-Shin;Lee, Gwang-Ryul;Han, Uk
    • Journal of the Korean association of regional geographers
    • /
    • v.11 no.2
    • /
    • pp.278-290
    • /
    • 2005
  • This study deals with the geomorphic, environmental and land use changes by comparative analysis using Landsat TM images of 1988 year and ETM ones of 2002 year, partly together with the new Quick Bird images having 60cm resolution for more detail analysis, focusing on the Oncheon gun(county) in Pyeongnam Province, west coast zone of North Korea. The main analysis methodology is neural network classification, which is more advanced techniques for the classification of land cover and land use, with higher accuracy rate and lower errors. The TM images of 1988 year show, mainly, the on-construction tide embank for the reclamation at Gwangryangman bay and salt farm on the reclaimed tidal flat. But, ETM images of 2002 year present stabilized reclaimed land, salt farm and rice field, recently transformed from salt farm. Especially, new tidal land has been naturally developed on the coastal shallow out of tide embank and salt farm. The results of the study may help to database coastal environmental changes and to support for reasonable and productive land use of North Korea, and to manage and plan unified national land in the near future.

  • PDF

A Study on the Analysis and Application of the Satellite Data for Study of Urban and Region (도시 및 지역연구를 위한 인공위성 Data의 분석 및 그 활용방안에 관한 연구)

  • 안철호;윤정섭;안기원
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.3 no.1
    • /
    • pp.1-13
    • /
    • 1985
  • This study is about the analysis and application of the Satellite(in particular, LANDSAT) Data for the study of urban and region. Land cover maps and change of each classes for a period of years of Seoul, Daejeon, and Incheon cities were extracted by use of LANDSAT MSS Data and MSS Image Analysis System. From the results of this study, it was proved that Satellite data could be used on the study of urban and region to obtain fully fruitful results.

  • PDF

Simulation of the Reduction Effect of Soil Loss Using SWAT Model (SWAT 모형을 이용한 토양유실량 저감효과 모의)

  • Jeong, Jin-Kweon;Kim, Hwan-Gi
    • Journal of Environmental Impact Assessment
    • /
    • v.17 no.4
    • /
    • pp.243-253
    • /
    • 2008
  • The purpose of this study was to simulate the reduction effect of soil loss in the Yongdam reservoir watershed using SWAT model. To evaluate accuracy for flow and sediment yield of SWAT model, calibration was performed for the period from Jan. 2002 to Dec. 2003, and the verification for Jan. 2005 to Dec. 2005. The calibration and the verification were carried out using data observed at the Cheoncheon gaging station. The $R^2$ and EI values in terms of a flow were 0.8 and 0.78 respectively for calibration, whereas they for verification were 0.88 and 0.86 respectively. In terms of a sediment yield, they were 0.7 and 0.48 respectively for calibration, whereas for verification were 0.64 and 0.54 respectively. As a results from model simulation, annual mean soil loss rates in terms of forest, paddy and upland were 0.02 ton/ha/yr, 0.15 ton/ha/yr and 7.58 ton/ha/yr, respectively. The results show that the land use type of a upland has more significant impact on a total soil loss as well as a sediment yield than other types of land use. The sediment delivery ratio was determined to be about 0.35. In this study 2 land cover change scenarios for upland area were considered. These scenarios were used an input to SWAT model in order to evaluate their impact on soil loss and sediment delivery. The results show that a reduction of the upland area would reduce the soil loss and sediment yield.

Comparative Evaluation between Administrative and Watershed Boundary in Carbon Sequestration Monitoring - Towards UN-REDD for Mt. Geum-gang of North Korea - (탄소 저장량 감시에서 배수구역과 행정구역의 비교 평가 - 금강산에 대한 UN-REDD 대응 차원에서 -)

  • Kim, Jun-Woo;Um, Jung-Sup
    • Journal of Environmental Impact Assessment
    • /
    • v.22 no.5
    • /
    • pp.439-454
    • /
    • 2013
  • UN-REDD (United Nations programme on Reducing Emissions from Deforestation and forest Degradation) is currently being emerged as one of important mechanism to reduce carbon dioxide in relation to the deforestation. Although administrative boundary has already gained world-wide recognition as a typical method of monitoring unit in the process of GHG (Greenhouse Gas) reduction project, this approach did not provide a realistic evidence in the carbon sequestering monitoring in terms of UN-REDD; the meaningful comparison of land use patterns among watershed boundaries, interpretation for distribution trends of carbon density, calculation of opportunity cost, leakage management, etc. This research proposes a comparative evaluation framework in a more objective and quantitative way for carbon sequestering monitoring between administrative and watershed boundary approaches. Mt. Geumgang of North Korea was selected as a survey objective and an exhaustive and realistic comparison of carbon sequestration between the two approaches was conducted, based on change detection using TM satellite images. It was possible for drainage boundary approach to identify more detailed area-wide patterns of carbon distribution than traditional administrative one, such as estimations of state and trends, including historical trends, of land use / land cover and carbon density in the Mt. Geumgang. The distinctive changing trends in terms of carbon sequestration were specifically identified over the watershed boundary from 4.0% to 34.8% while less than 1% difference was observed in the administrative boundaries, which were resulting in almost 21-22%. It is anticipated that this research output could be used as a valuable reference to support more scientific and objective decision-making in introducing watershed boundary as carbon sequestering monitoring unit.

Assessing Future Climate Change Impact on Hydrologic Components of Gyeongancheon Watershed (기후변화가 경안천 유역의 수문요소에 미치는 영향 평가)

  • Ahn, So-Ra;Park, Min-Ji;Park, Geun-Ae;Kim, Seong-Joon
    • Journal of Korea Water Resources Association
    • /
    • v.42 no.1
    • /
    • pp.33-50
    • /
    • 2009
  • The impact on hydrologic components considering future potential climate, land use change and vegetation cover information was assessed using SLURP (Semi-distributed Land-Use Runoff Process) continuous hydrologic model. The model was calibrated (1999 - 2000) and validated (2001 - 2002) for the upstream watershed ($260.4\;km^2$) of Gyeongancheon water level gauging station with the coefficient of determination and Nash-Sutcliffe efficiency ranging from 0.77 to 0.60 and 0.79 to 0.60, respectively. Two GCMs (MIROC3.2hires, ECHAM5-OM) future weather data of high (A2), middle (A1B) and low (B1) emission scenarios of the IPCC (Intergovernmental Panel on Climate Change) were adopted and the data was corrected by 20C3M (20th Century Climate Coupled Model) and downscaled by Change Factor (CF) method using 30 years (1977 - 2006, baseline period) weather data. Three periods data of 2010 - 2039 (2020s), 2040 - 2069 (2050s), 2070 - 2099 (2080s) were prepared. To reduce the uncertainty of land surface conditions, future land use and vegetation canopy prediction were tried by CA-Markov technique and NOAA NDVI-Temperature relationship respectively. MIROC3.2 hires and ECHAM5-OM showed increase tendency in annual streamflow up to 21.4 % for 2080 A1B and 8.9 % for 2050 A1B scenario respectively. The portion of future predicted ET about precipitation increased up to 3 % in MIROC3.2 hires and 16 % in ECHAM5-OM respectively. The future soil moisture content slightly increased compared to 2002 soil moisture.

Terrace Fields Classification in North Korea Using MODIS Multi-temporal Image Data (MODIS 다중시기 영상을 이용한 북한 다락밭 분류)

  • Jeong, Seung Gyu;Park, Jonghoon;Park, Chong Hwa;Lee, Dong Kun
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.19 no.1
    • /
    • pp.73-83
    • /
    • 2016
  • Forest degradation reduces ecosystem services provided by forest and could lead to change in composition of species. In North Korea, there has been significant forest degradation due to conversion of forest into terrace fields for food production and cut-down of forest for fuel woods. This study analyzed the phenological changes in North Korea, in terms of vegetation and moisture in soil and vegetation, from March to Octorber 2013, using MODIS (MODerate resolution Imaging Spectroradiometer) images and indexes including NDVI (Normalized Difference Vegetation Index), NDSI (Normalized Difference Soil Index), and NDWI (Normalized Difference Water Index). In addition, marginal farmland was derived using elevation data. Lastly, degraded terrace fields of 16 degree was analyzed using NDVI, NDSI, and NDWI indexes, and marginal farmland characteristics with slope variable. The accuracy value of land cover classification, which shows the difference between the observation and analyzed value, was 84.9% and Kappa value was 0.82. The highest accuracy value was from agricultural (paddy, field) and forest area. Terrace fields were easily identified using slope data form agricultural field. Use of NDVI, NDSI, and NDWI is more effective in distinguishing deforested terrace field from agricultural area. NDVI only shows vegetation difference whereas NDSI classifies soil moisture values and NDWI classifies abandoned agricultural fields based on moisture values. The method used in this study allowed more effective identification of deforested terrace fields, which visually illustrates forest degradation problem in North Korea.

Evaluation of Phosphorus Release Potential in Arable land with Different Landuse by Phosphorus Threshold (변곡점을 이용한 영농형태별 토양 인산 유출 잠재력 평가)

  • Lee, Seul-Bi;Lee, Chang-Hoon;Hong, Chang-Oh;Lee, Yong-Bok;Kim, Pil-Joo
    • Korean Journal of Environmental Agriculture
    • /
    • v.29 no.4
    • /
    • pp.343-347
    • /
    • 2010
  • Heavy application of fertilizer and manure in excess from the optimum requirement for crop growth can increase phosphorus (P) accumulation and P release potential in soils. In this study, the relationship between soil test P and 0.01M $CaCl_2$ extractable P was analysed to evaluate the P release potential of agricultural soils under different land-use. The paddy, upland, plastic film house(PFH) soils were sampled from Tongyoung and Changnyeong, and Daegok areas in Gyeongnam province, respectively. With respect to the P accumulation, available P contents in upland and PFH soils were 619 and 796 mg $P_2O_5$/kg, respectively indicating that different land-use types can greatly impact soil P accumulation. As soil available P was increased in the paddy soil, the content of 0.01M $CaCl_2$ extractable P also linearly increased without change point. Comparatively, P threshold were detected at 520 mg $P_2O_5$/kg in both upland and PFH soils, indicating that P release potential were higher in these land-use systems. For reducing P release from agricultural soils, management of optimum P content is needed in soils possessing high P release potential. Further, the change point value, if it is to be used as an environmental indicator, requires more detailed investigation to cover a wide range of soil characteristics.