• Title/Summary/Keyword: GIS data

Search Result 3,355, Processing Time 0.028 seconds

Change of the Land Use in Yanji city of China in the Connection with Urbanization Process (도시화에 따른 중국 연길시 토지이용의 변화)

  • Li, Mingyu
    • Journal of the Korean association of regional geographers
    • /
    • v.12 no.2
    • /
    • pp.323-337
    • /
    • 2006
  • This thesis aims to study Change of the Land Use in Yanji city since the reformation and opening of China in the Connection with Urbanization Process. This study is based on Landsat image and maps and data related to topography, urban planning basic, the cadastral map were employed. Softwares such as Arcview3.3, ArcGis8.0 were used. The result of the research is as follows. It clearly appears that there have decreased in the ratio of agricultural areas since the increase in other urban usage of land. There has greatly increased in residential, commercial and industrial areas. Such as the capitalist and market economic city the highest point of city land price emerged in downtown of the old city center. In addition spatial pattern of land price is unusually quite different from the western city in its pattern of land price surface declining tendency between the highest land price and the lowest land price. The land price surface shows irregular patterns with increase of distance from downtown due to various urban developments. According to the land price distribution map, it is possible to guess spatial development of the city that the north-eastern part of Yanji was developed prior to south-western area. The center of the city, or downtown expanded to eastward, and the city expanded to south-westward out skirt. Along the main road, Xin-xing areas developed toward east and west ward.

  • PDF

Rate of Shoreline Changes for Barrier Islands in Nakdong Estuary (낙동강 하구역 울타리 섬의 해안선 변화율)

  • Kim, Baeck-Oon;Khim, Boo-Keun;Lee, Sang-Ryong
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.19 no.4
    • /
    • pp.361-374
    • /
    • 2007
  • This study presents long-term shoreline changes of barrier islands in Nakdong Estuary using aerial photographs. Digital photogrammetry is used for constructing mosaic aerial photographs, which yield six sets of shoreline data ranging from 1975 to 2001. Three kinds of rate of shoreline changes such as EPR (End Point Rate), JKR(Jackknife Rate) and LRR (Linear Regression Rate) are computed by a GIS-based Digital Shoreline Analysis Systems. There have been remarkable changes both in Sinja Island and Doyodeung. Western part of Sinja Island advanced seaward, whereas eastern part retreated landward, giving appearance that the island rotated counterclockwise. Rate of shoreline changes at both ends reach 20 m/yr. Doyodeung occurred newly in front of Baekhapdeung in 1993, resulting in shoreline advance in a rate of 40 m/yr. Rate of shoreline changes differ both within and between barrier islands and have a tendency to increase eastward. To understand this spatial variability of rate of shoreline changes, it is suggested to make a detailed investigation into the impact of coastal development on hydrodynamic and sedimentary processes.

Analysis of the Controlling Factors of an Urban-type Landslide at Hwangryeong Mountain Based on Tree Growth Patterns and Geomorphology (부산 황령산에서의 수목 성장 및 지형 특성을 이용한 도시 산사태의 발생원인 분석)

  • Choi, Jin-Hyuck;Kim, Hyun-Tae;Oh, Jae-Yong;Kim, Young-Seog
    • The Journal of Engineering Geology
    • /
    • v.21 no.4
    • /
    • pp.281-293
    • /
    • 2011
  • We investigated the causes and characteristics of a landslide at Hwangryeong Mountain, Busan, based on aerial photos, annual precipitation data, rock fracture patterns, and geomorphic features using GIS Software, and a statistical analysis of tilted trees. The analyzed slope shows evidence of a previous slope failure event and the possibility of future failures. Although the NW-SE trending slope was relatively stable until 1975, a large-scale slope failure occurred between 1975 and 1985 due to complex factors, including favorably oriented geologic structures, human activity, and heavy rain. This indicates that a detailed study of geologic structures, slope stability, and rainfall characteristics is important for slope cuttings that could be a major factor and cause of urban landsliding events. The statistic analysis of tilted trees shows a slow progressive creeping type of mass wasting with rock falls oblique to the dip of the slope, with the slope having moved towards the west since 1985. A concentration of tree tilting has developed on the northwestern part of the slope, which could reach critical levels in the future. The analysis of deformed trees is a useful tool for understanding landslides and for predicting and preventing future landslide events.

A Study on Detection of Deforested Land Using Aerial Photographs (항공사진을 이용한 훼손 산지 탐지 연구)

  • Ham, Bo Young;Lee, Chun Yong;Byun, Hye Kyung;Min, Byoung Keol
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.21 no.3
    • /
    • pp.11-17
    • /
    • 2013
  • With high social demands for the diverse utilizations of forest lands, the illegal forest land use changes have increased. We studied change detection technique to detect changes in forest land use using an object-oriented segmentation of RED bands differencing in multi-temporal aerial photographs. The new object-oriented segmentation method consists of the 5 steps, "Image Composite - Segmentation - Reshaping - Noise Remover - Change Detection". The method enabled extraction of deforested objects by selecting a suitable threshold to determine whether the objects was divided or merged, based on the relations between the objects, spectral characteristics and contextual information from multi-temporal aerial photographs. The results found that the object-oriented segmentation method detected 12% of changes in forest land use, with 96% of the average detection accuracy compared by visual interpretation. Therefore this research showed that the spatial data by the object-oriented segmentation method can be complementary to the one by a visual interpretation method, and proved the possibility of automatically detecting and extracting changes in forest land use from multi-temporal aerial photographs.

Regional Ecological Network Design for Wild Animals' Movement Using Landscape Permeability and Least-cost Path Methods in the Metropolitan Area of Korea (경관투과성 및 최소비용경로 분석을 통한 수도권 지역의 광역생태축 구축 연구)

  • Lee, Dong-Kun;Song, Won-Kyong;Jeon, Seong-Woo
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.11 no.3
    • /
    • pp.94-106
    • /
    • 2008
  • As populations inhabiting in natural ecosystem are fragmented by artificial barriers and habitats are destructed by development, extinction possibility of species is getting higher. It is necessary to design and to manage conservation areas and corridors considering animals' movement and migration for sustainable species diversity in present circumstances. 'Least-cost modeling' is one commonly employed approach in which dispersal costs are assigned to distinct habitat types and the last-costly dispersal paths among habitat patches are calculated using a geographical information system (GIS). This study aims to design ecological corridor using least-cost path method and to apply it to a regional ecological network considering movability of medium-large size mammals. This study was carried out over the metropolitan area, which has been deforested by rapid urbanization. Nevertheless there is connected with Gangwon province, Baekdudaegan mountain range and DMZ, considered where many forest species can migrate to this region. This study employs such an approach to develop least-cost path models for medium-large size mammals, have inhabited for this entire region. Considering those species, two forest areas as a source of species supply and forest areas more than 1,000ha are selected as focal forest areas. Movement and migration paths from species supply sources to focal forest areas are calculated by applying landscape permeability theory using land cover map, road density map and land slope map. Results showed least-cost paths from species supply sources to focal forest areas on two species. Wildcat and roe deer are different in some least-cost paths caused by their landscape permeability but paths show generally same specifics. The result of considering regional distribution of expected movement and migration paths to regional ecological network, low altitude mountains of western metropolitan area are evaluated important area for species connectivity. In national or regional levels ecological connectivity is essential to promote species diversity and to preserve integrated ecosystem. This study concludes that developing least-cost models from similar empirical data could significantly improve the utility of these tools.

A study on the Realtime Update of the Digital-Map by the General Survey Map (일반측량성과도에 의한 수치지도의 수시갱신방법 연구)

  • Lee, Sang-Gil;Kwon, Jay-Hyoun;Jeon, Jae-Han
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.15 no.3
    • /
    • pp.19-26
    • /
    • 2007
  • The renewal update of the digital map constructed through NGIS has been conducted for the enhancement of usage, maintenance so that the latest data is guaranteed. The total update has been done every five years for five regions of the country using aerial photographs and satellite images. By launching the third phase of NGIS, the updating plan was changed from total to total or partial update including the real time update scheme. Furthermore, the update period was improved from five to two years and four years for a large and a small city, respectively. Therefore, it is necessary to develope a matching technique which combines various geographic information (such as drawing map, surveying drawing and map) with exact position on the digital map. In this study, we developed a matching algorithm based on central point and suggested a method which uses general surveying drawing for revision/update of the digital map. The general survey is conducted when a civilian development on lands are approved. Thus, the outcome from the survey, which is the general survey drawing, contains the latest various contents such as road, building, water pipe and manhole. A consistent and efficient method using the general survey drawing for near real time update of the digital map by applying the developed matching algorithm is presented.

  • PDF

Analysis of Non-Barrier Space to Promote the Uses of Convenience Facilities at Passenger Facilities by the Visually Handicapped (시각장애인의 여객시설 내부편의시설 이용증진을 위한 무장애 공간 분석(광명역을 중심으로))

  • Kim, Dong-Moon;Kim, Hwang-Bae;Park, Jae-Kook
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.16 no.2
    • /
    • pp.31-40
    • /
    • 2008
  • The indicators of an advanced society include the overall level of life quality and satisfaction among all the members. The overall life quality has close relationships with accessibility to urban space for the social weak. Access to facilities of interest and right of mobility in urban space are very important issues to the weak class in terms of transportation including the visually handicapped. In particular, great significance is endowed upon transfer facilities, which play mediating roles between facilities like passenger facilities, and the convenience facilities inside for the disabled, which are usually the only means for the disabled to access each facility. As they are provided to the visually handicapped as well, it's very important to analyze the concerned spatial distribution and offer the results. The previous studies on the subject, however, merely covered the perceptions of the users and the related statistical analysis. This study set out to analyze non-barrier space to promote the utilization of convenience facilities at passenger facilities by the visually handicapped and to secure their right of mobility by using a GIS for spatial analysis based on spatial data. The results show that it's urgent to supplement the existing space for the handicapped and that it's necessary to expand convenience facilities for the disabled such as paths with Braille points on them to promote their use of diverse convenience facilities inside.

  • PDF

Applied geography:retrospect and prospects (응용지리학 일반의 회고와 전망)

  • ;Lee, Hee-Yeon
    • Journal of the Korean Geographical Society
    • /
    • v.31 no.2
    • /
    • pp.329-345
    • /
    • 1996
  • The purposes of this study are to review research trends of applied geography field, to retrospect geographical works done by Korean geographers in applied geography, and to prospect the future of applied geography. We are in the period where societal problems such as energy, transportation, pollution, environment, health care, and many others, require careful consideration and need throughout strategies for solution. Most societal problems have some geographical dimensions. Because these problems are geographic in nature, there is an obvious implication that geography as a discipline has something to offer in their solutions. In fact, most geographic problems are best presented and analyzed through the applications of geographic theories, concepts and tools. Applied geography is a branch of general geography. It relies on the scientific methods and uses the principles and methods of pure geography. However applied geography is different in that it analyzes and evaluates real world action and planning and seeks to implement and manipulate environmental and spatial realities. Thus, geographic theories and other social theories that have geographic dimensions are fundamental to applied geography. Applied geography has a short history as theme in Korean geography. During the last two decades. Korea achieved remarkable economic growth. We have also encountered widening regional disparity, housing shortage of larger cities, transportation congestion, environmental pollution and many other problems. Applied geographers have tried to analyze and solve such spatial problems during the last 30 years. The research trend of Korean applied geography can be subdivided into 5 categories: (1) land use analysis and efficient utilization, (2) national physical development and planning. (3) regional development and regional planning, (4) tourism and location-allocation, transportation planning. Still the overconcentration of Seoul metropolitan region and unbalanced regional development are perceived to be the serious spatial problems which may induce more works to solve these problems. In Korea new emphasis has to be given to some professional training and experimental learning, including methodology, field techniques data management, statistical analysis, cartography, GIS, and other tools, as applicable and beneficial to problem solving in real world. The growth of applied geography depends on new insights and purposed solutions of future applied geographers in Korea. Applied geographers will contribute to the creation of future Korean geographies.

  • PDF

Analysis of Soil Erosion Hazard Zone by R Factor Frequency (빈도별 R인자에 의한 토양침식 위험지역 분석)

  • Kim, Joo-Hun;Oh, Deuk-Keun
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.7 no.2
    • /
    • pp.47-56
    • /
    • 2004
  • The purpose of this study is to estimate soil loss amount according to the rainfall-runoff erosivity factor frequency and to analyze the hazard zone that has high possibilities of soil erosion in the watershed. RUSLE was used to analyze soil loss quantity. The study area is Gwanchon that is part of Seomjin river basin. To obtain the frequency rainfall-runoff erosivity factor, the daily maximum rainfall data for 39 years was used. The probability rainfall was calculated by using the Normal distribution, Log-normal distribution, Pearson type III distribution, Log-Pearson type III distribution and Extreme-I distribution. Log-Pearson type III was considered to be the most accurate of all, and used to estimate 24 hours probabilistic rainfall, and the rainfall-runoff erosivity factor by frequency was estimated by adapting the Huff distribution ratio. As a result of estimating soil erosion quantity, the average soil quantity shows 12.8 and $68.0ton/ha{\cdot}yr$, respectively from 2 years to 200 years frequency. The distribution of soil loss quantity within a watershed was classified into 4 classes, and the hazard zone that has high possibilities of soil erosion was analyzed on the basis of these 4 classes. The hazard zone represents class IV. The land use area of class IV shows $0.01-5.28km^2$, it ranges 0.02-9.06% of total farming area. Especially, in the case of a frequency of 200 years, the field area occupies 77.1% of total fanning area. Accordingly, it is considered that soil loss can be influenced by land cover and cultivation practices.

  • PDF

Estimation of Water Quality Environment in Youngsan and Seumjin River Basins (영산강과 섬진강 유역의 하천 수질환경 평가)

  • 양해근;최희철
    • Journal of the Korean Geographical Society
    • /
    • v.38 no.1
    • /
    • pp.16-31
    • /
    • 2003
  • The water quality environment in Youngsan and Seumjin river basins was investigated based on the concept of the comprehensive Water Quality Index (WQI) and a spacial pollution source. Artificial factors influencing to river water quality have been analyzed. The specific delivery load of Youngsan river basin was found to be 8.34~97.25 kg/day/$\textrm{km}^2$, Gomagwon stream and Gwangju stream showed the relatively high rates as 97.25 kg/day/$\textrm{km}^2$ and 86.06 kg/day/$\textrm{km}^2$, respectively. The specific delivery load in Seumjin river basin was estimated to be 10.98∼19.51 kg/day/$\textrm{km}^2$, Suggesting no Significant Contribution of pollution. WQI of Youngsan watershed revealed 1.36~3.45, whereas Seumjin watershed showed a relatively low value of 0.5~1.47 And it is concluded that the specific delivery load suggested in this study provides the essential core data of the upper limit of pollutants receptor in the watershed area studied. From this study, it is suggested that the integrated environmental management of river basin requires the analysis of pollutants generation rate of the basin and the receptor capability for the self-purification.