• Title/Summary/Keyword: GSIS

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Evaluation of GIS-based Soil Loss Amount in Considering Basin Characteristics (유역특성을 고려한 GIS 기반 토양침식량 평가)

  • Guak Dong-Wook;Cho Gi-Sung
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.24 no.1
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    • pp.89-97
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    • 2006
  • Soil erosion has caused serious environmental problems which threaten the foundation of natural resources. In this paper, we chose RUSLE erosion model, which could be connected easily with GSIS and available generally in mid-scale watershed among soil erosion models, and extracted factors entered model by using GSIS spatial analysis method. First, this study used GIS database as soil map, DEM, land cover map and rainfall data of typhoon Memi (2003) to analyze soil loss amount of Dam basin. To analyze the changes of soil loss in considering basin characteristics as up-, mid- and downstream, this study calculated soil erodibility factor (K), topographic factors (LS), and cover management factor (C). As a result of analysis, K and LS factors of upstream showed much higher than those of downstream because of the high ratio of forest. But C factor of downstream showed much higher than that of upstream because of the high ratio of agricultural area. As a result of analysis of soil loss, unit soil loss of upstream is 4.3 times than soil loss of downstream. Therefore, the establishment of countermeasures for upstream is more efficient to reduce soil loss.

A STUDY ON THE ANALYSIS OF DIGITAL AERIAL PHOTO USING IMAGE SEGMENTATION (영상분할기법을 이용한 수치항공영상 해석에 관한 연구)

  • Kwon, Hyun;Lee, Hyun-Jik;Park, Hyo-Keun
    • Journal of Korean Society for Geospatial Information Science
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    • v.2 no.2 s.4
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    • pp.131-142
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    • 1994
  • Generally, there are two methods which generates the base map of Geo-Spatial Information System(GSIS). one is the digitizing of existing map, and the other is the analytical plotting method editing data acquired by sensors using computers. But the analytical plotting method and method of the digitizing of existing map is technically complex and has the disadvantages in the costs and time. The subject region of study(the Kwangyang province), was photographed by aircraft, and photographing scale was 1/6,000. Then this area was divided into two specific regions, the residential area, and the agricultural area. In this study, we developed the algorithm that generated base map of database in GSIS from the aerial photo. This algorithm is as followed. First, the digital aerial photos were generated using these aerial photos. Second, these digital aerial photos were enhanced by implementing the histogram equalization. Third, the objects of the enhanced images were extracted by implementing thresholding and edged detection techiques of image segmentation. Finally, these images could be used to updated the base map of database in GSIS. The result obtained from this study showed that method used by this study were more efficient than existing method in costs and time.

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A Study on Development of Bridge Maintenance and Management System Using GSIS (GSIS를 이용한 교량 유지보수 이력관리 체계 개발에 관한 연구)

  • Yeu, Bock-Mo;Joo, Hyun-Seung
    • Journal of Korean Society for Geospatial Information Science
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    • v.7 no.2 s.14
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    • pp.133-141
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    • 1999
  • Collapse of a huge structural material has brought about enormous loss of lives and property. Every construction may be destroyed by the nature's power and careless mistake of human as well as its own defect. So a great number of concern and detailed managing technique are demanded not in constructing work but also in management of constructed material. The Interest of construction safety has Increased rapidly and a plenty of effort has been attempted to manage systematically. In this study, the use of FM(Facilities Management) as a branch of GSIS(Geo-spatial Information System) was developed to offer the users convenient managing achievement and establishment of history managing system in the bridge management system. This study accomplished dividing all information of images, photos, drawing and etc. into their items of time, material and the person in charge, and developed to stue and maintain those items in database. Related database which is composed of recording of check, retrieving and adding the data was accomplished to an easy access of database, and by using these data as output for example images, m display, report and hard copy, this system was proved to help manage efficiently in bridge management system.

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A Study on the Spatial Determination of Red Tide Occurrence Area Using GSIS (GSIS 이용한 적조발생지의 공간결정 연구)

  • Kim, Jin-Gi
    • Journal of Korean Society for Geospatial Information Science
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    • v.15 no.2 s.40
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    • pp.51-57
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    • 2007
  • Few researches related to the spatial determination of areas where red tide occurs have been performed, so accurately determining the area where red tide occurs and disappears poses difficulties. Therefore, a more objective and scientific method is necessary to analyze the occurrence and movement of red tide based on a geo-spatial information system. In this study, the coastline was extracted using a digital topographic map in order to examine areas where red tide occurs each year. An analysis of red tide occurrence areas, which were determined based on red tide data for the last several years, showed that only Yeoja bay had almost a zero case of red tide of the areas studied, whereas Dolsando in the South Sea and NamHaedo Aenggang bay areas exhibited the highest frequency of red tide occurrences. Based on these results, by using a system that determines the geo-spatial distribution status of areas repeatedly hit by red tide every year, it would be possible to predict the course of red tide and prevent consequent damages.

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SOIL ORGANIC CARBON APPRAISAL IN A SEMI-EVERGREEN FOREST, EASTERN GHATS OF INDIA AS A RESULT OF DEGRADATION - A GEOSPATIAL STUDY

  • Jayakumar, S.;Ramachandran, A.;Bhaskaran, G.;Cho, Hyoung-Sig;Heo, Joon
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.98-100
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    • 2007
  • Tropical forests have variety of biodiversity values, which provide invaluable services to the living being on earth. In the recent years, tropical forests are regarded as valuable global resources that act as sink for carbon dioxide in order to mitigate global climatic change. In many parts of the world, tropical forests are being rapidly cleared by various means. Soil organic carbon (SOC) is concentrated in the upper 12 inches of the soil. So it is readily depleted owing to the degradation activities. In the present study, it was aimed to assess the magnitude of disturbance in the availability of SOC in a semi- evergreen forest, situated in the Eastern Ghats of Tamil Nadu, India. The forest density of this region was mapped with QuickBird satellite data. Intensive field soil sampling and floristic study were conducted to estimate the SOC status in different density classes and to identify the species availability. The SOC density ranged from 274.06 t/ha to 147.84 t/ha in the very dense and degraded semi-evergreen forest respectively. The SOC content was also varied from 3.70 to 1.83 % in the very dense semi-evergreen and medium semi-evergreen forests respectively. The species composition in different density classes was also varied considerably. As a result of this study, it was identified that the disturbance to forests by various means not only affect the density of forests but also affect the below ground SOC status proportionately.

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MAPPING OF EUCALYPTUS PLANTATIONS THROUGH TEMPORAL SATELLITE DATA IN CHINA

  • Heo, Joon;Jayakumar, S.;Lee, Jung-Bin
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.471-474
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    • 2007
  • Eucalyptus plantations play a major role in the China's ecological, social, economic and other aspects and presently China is the second largest producer of Eucalyptus in the world next to Brazil. It was introduced as an ornamental tree during 1890 but later it became a commercial crop. During 1960s large number of Eucalyptus timber were used for railway sleepers and it was also used as shelter belt for rubber trees. It becomes one of the important national resources of commercial timber once the production reached to 5 million $m^{3}/yr$. Through Eucalyptus oil, it brought about 20% of foreign exchange. In the present study, it was aimed to estimate the Eucalyptus growing area in the southern Guangdong in China in terms of aerial extent and changes between 1991 and 2001 using Landsat TM and ETM+ data. Object based classification technique and subsequent temporal change detection analysis were followed to identify the changes between the periods. In the present study, the total area was divided into three classes viz., plantation area with trees, plantation area without trees and others. Object oriented classification was found to be more accurate in the present study. Overall increase of about 23.62 $km^{2}$ was noted between 1991 and 2001 in the plantation area. With reference to the present study area, the growth of Eucalyptus growing area was 7.4% in the 10 year periods. From this study it is clear that the area under Eucalyptus cultivation is growing considerably year by year in China. However, elaborate study must be conducted considering larger areas to accurately predict the growth of Eucalyptus growing areas.

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Determination of the Improvement Priority in a Small River Using GRID Analysis Technology of GSIS (GSIS의 그리드 분석 기법에 의한 소하천 정비 우선순위 결정)

  • 양인태;최영재;오명진
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.18 no.3
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    • pp.233-240
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    • 2000
  • A small rivers take advantage of not only a site of superb scenic beauty, a play space, a rest place but also a momentous waters reservoir, a drainage on territory residents. Likewise, part of the most massed a life space to a region dwellers shall be extremely in harmony with coexistence space in that every kind plant, animal over again a human being and so on. For improvement planning of small river, various way and model are presented. But, it's want of ability for small rivers of a adaption many-side and throwing in a lot of financial resources. Because the improvement planning of small river was designed all small river in a county, the priority must be preprocessed. Now, the counties prioritized for improvement planning of small river are a few, and acquisition and manipulation of the data are time-consuming. Geo-Spatial Information System (GSIS) is specifically designed to manage and analyze spatial data. It will be to offer the benefit to the determination of the improvement priority in a small river. The purpose of this study is to offer priority for improvement planning of small river using GSIS. For this purpose, it was developed using Arc/Info software and AML was used as a developing tool.

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A Study on the extraction of hydrologic-Model input parameter using GSIS (GSIS를 이용한 수문모형 입력매개변수 추출에 관한 연구)

  • Lee, Geung-Sang;Chae, Hyo-Seok;Park, Jeong-Nam;Cho, Gi-Sung
    • Journal of Korean Society for Geospatial Information Science
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    • v.8 no.2 s.16
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    • pp.11-22
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    • 2000
  • It needs to extract the accurate topological characteristics and hydrological parameters of watershed in order to manage water resource efficiently. But, these data are processed yet by manual wok and simple operation in hydrologic fields. In this paper, we presented algorithm that could extract topological characteristics and hydrological parameters over watershed using GSIS and it gives the saving of data processing tin and the confidency of data. We presented coupling method between GSIS and hydrologic model by using extracted parameters into the input parameter of HEC-HMS hydrologic model. The extraction procedure of topological characteristics and hydrological parameters is as below. First, watershed and stream are extracted by DEM and curve unmber is extracted throughout the overlay of landuse map and soil map. Also, we extracted surface parameters like the length of the longest flow path and the slope of the longest flow path by Grid computation into watershed and stream. And we gave the method that could extract hydrologic parameters like Muskingum K and sub-basin lag tin by executing computation into surface parameters and average Sn curve number being extracted.

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A study about the application of GSIS on Airport site selection (공항입지선정(空港立地選定)에 있어서 GSIS의 활용(活用)에 관(關)한 연구(硏究))

  • Jeong, Seung-Hyeon;Lim, Seoung-Hyeon;Kim, Tea-Geun;Cho, Gi-Sung
    • Journal of Korean Society for Geospatial Information Science
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    • v.5 no.1 s.9
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    • pp.27-40
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    • 1997
  • Recently, with the demand for airservice increasing and localization accelerating, airport construction is booming. However, in the case of an unsuitable airport site selection, it might cause a reduction in airport service and a decrease in airport demand. Thus, it is necessary to construct a representative airport and choose a suitable site selection method for economical and efficient airports in order to make the utmost use of airport functions. In this study, GSIS was used to select the airport site and applied to case study areas. GSIS could present a new method for efficient and scientific analysis in airport site selection including various factors over an extensive area. The use of both, the paired comparison method and the delphi method, could improve the objectivity of analysis results in the process considering the relative weight grade of data and priority order of analysis factors, used in airport site selection.

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