• Title/Summary/Keyword: Geographic difference

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An Analysis on the Changes of the Surface Hydrological Parameters using Landsat TM Data (Landsat TM 자료를 이용한 지표면 수문인자 변화 분석)

  • Chae, Hyo-Sok;Song, Young-Soo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.2 no.3
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    • pp.46-59
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    • 1999
  • Remote sensing provides informations on the changes of the hydrological states and variables over with the temporal and spatial distribution to monitor hydrological conditions and changes for large area. Especially, it can extract a spatial distribution of hydrological parameters such as surface albedo, vegetation informations, and surface temperature to effectively manage water resources of the watershed. In this study, we analyzed the characteristic of temporal and spatial changes in surface hydrological parameters which is necessary to identify the spatial distribution of water resources. 5 Landsat TM data of 1995 which is collected for Bochong-chon watershed, located in the upper stream of Keum River, were used to estimate characteristics on the change of hydrological parameters and atmospheric correction was carried out using COST model. The study showed that the difference of the albedo by the land cover was very sensitive depending upon the change of sun elevation and the amount of water in the soil. The difference between the surface temperature analysis and the measured air temperature was from $2.5^{\circ}C$ to $3.86^{\circ}C$.

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Analysis of Relationships Between Topography/Geology and Groundwater Yield Properties at Pohang using GIS (GIS를 이용한 포항시 지형 및 지질과 지하수 산출능력 간의 상관관계 분석)

  • Lee, Sa-Ro;Kim, Yong-Sung;Kim, Nam-Jin;Ahn, Kyoung-Hwan
    • Economic and Environmental Geology
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    • v.41 no.1
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    • pp.115-131
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    • 2008
  • The aim of this study is to analyze relationships between topography/geology which affects physically groundwater regime and groundwater yield properties in Pohang City using Geographic Information System (GIS). For the purpose, topographic factors such as ground elevation, ground elevation difference, ground slope, and ground regional slope, and hydrogeologic unit, and groundwater yield properties factors such as transmissivity, specific capacity, and well yield, were constructed to spatial data base. Then the relationships between topography, geology and groundwater yield properties were analyzed quantitatively using GIS overlay technique. As the results, ground-water yield of unconsolidated sediments and porous volcanic rocks is the highest among the hydrogeologic units of study area, and clastic sedimentary rock is the lowest. There are positive relationship between the elevation and elevation difference and the groundwater yield properties and negative relationship between the topographic slope and the groundwater yield properties.

야생 차나무 ( Thea sinensis L. Var. Bohea ) 의 Isogyme Patterns. ( Isogyme Patterns of Tea ( Thea Sinensis L. Var. Bohea ) in the Sourthern Area of Korea )

  • 안상득
    • Korean Journal of Plant Resources
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    • v.4 no.1
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    • pp.13-16
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    • 1991
  • Tea plant has been mllainly grown in shade aild wet flace of several temple surroundings for a long years in sourthern area of Korea, since it has been introduced about1,000 years ago In those rlaces, it has been mostly grown in semi-wild, but recentlycultivated in a part of Bosung-gun, Cheonnanl province. External forms of tea plantwere considered that those have a little changed according to geographic andclimatic conditions of growing places. To investigate how is the variation of teaplant by the difference of environment conditions under growing places, we had ex-amined the protein and isozyme patterns of seeds of tea plant. In spite of difference ofgeographic and climatic conditions, the patterns of catalase, esterase, acid phosphat-ase isozyme and protein showed the same aspects.

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Comparison of Precipitation Distributions in Precipitation Data Sets Representing 1km Spatial Resolution over South Korea Produced by PRISM, IDW, and Cokriging (PRISM, 역거리가중법, 공동크리깅으로 작성한 1km 공간해상도의 남한 강수 자료에서 강수 분포의 비교)

  • Park, Jong-Chul;Kim, Man-Kyu
    • Journal of the Korean Association of Geographic Information Studies
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    • v.16 no.3
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    • pp.147-163
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    • 2013
  • The purpose of this study is to compare precipitation distributions in precipitation data sets over South Korea produced by three interpolation methods. The differences of precipitation caused by interpolation methods is an important information when the interpolated precipitation data sets were used in researches such as ecological and hydrological modeling as well as regional climate impact studies. In this study, the precipitation data sets were produced by IDW(Inverse Distance Weighting) and Cokriging in this study and the PRISM(Precipitation-elevation Regressions on Independent Slopes Model) data set obtained from Climate Change Information Center of Korea. The spatial resolution of the precipitation data is 1km. As a result, there was a great precipitation difference caused by interpolation methods in data of mountainous watersheds in general. Especially the difference of monthly precipitation was 10~20% or more in the mountainous watersheds near the Military Demarcation Line dividing North and South Korea, Mt. Sobaik, Mt. Worak, Mt. Deogyu, Mt. Jiri and Taeback Mountain Range. It means that a final result of a research can be affected by adopted interpolation method when an interpolated precipitation data set is used in the research for the these study sites.

Wildfire-induced Change Detection Using Post-fire VHR Satellite Images and GIS Data (산불 발생 후 VHR 위성영상과 GIS 데이터를 이용한 산불 피해 지역 변화 탐지)

  • Chung, Minkyung;Kim, Yongil
    • Korean Journal of Remote Sensing
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    • v.37 no.5_3
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    • pp.1389-1403
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    • 2021
  • Disaster management using VHR (very high resolution) satellite images supports rapid damage assessment and also offers detailed information of the damages. However, the acquisition of pre-event VHR satellite images is usually limited due to the long revisit time of VHR satellites. The absence of the pre-event data can reduce the accuracy of damage assessment since it is difficult to distinguish the changed region from the unchanged region with only post-event data. To address this limitation, in this study, we conducted the wildfire-induced change detection on national wildfire cases using post-fire VHR satellite images and GIS (Geographic Information System) data. For GIS data, a national land cover map was selected to simulate the pre-fire NIR (near-infrared) images using the spatial information of the pre-fire land cover. Then, the simulated pre-fire NIR images were used to analyze bi-temporal NDVI (Normalized Difference Vegetation Index) correlation for unsupervised change detection. The whole process of change detection was performed on a superpixel basis considering the advantages of superpixels being able to reduce the complexity of the image processing while preserving the details of the VHR images. The proposed method was validated on the 2019 Gangwon wildfire cases and showed a high overall accuracy over 98% and a high F1-score over 0.97 for both study sites.

Analysis of Urban Thermal Environment for Environment-Friendly Spatial Plan (친환경적 공간계획을 위한 도시의 열환경 분석)

  • Lee, Woo-Sung;Jung, Sung-Gwan;Park, Kyung-Hun;Kim, Kyung-Tae
    • Journal of the Korean Association of Geographic Information Studies
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    • v.13 no.1
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    • pp.142-154
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    • 2010
  • The purpose of this study is to analyze the effects of various spatial characteristics on the land surface temperature and to grasp the characteristics of thermal environment by types of urban area in Changwon, Gyeongsangnam-do. The spatial data were consisted LST, normalized difference built-up index(NDBI) and normalized difference vegetation index(NDVI) obtained from Landsat 5 TM and land use and land cover map classified from high resolution digital aerial photograph($10cm{\times}10cm$). The unit space for spatial analysis was built by $500m{\times}500m$ Vector GRID. According to the results of estimation of relationship between thermal environment and spatial characteristics, LST had the highest positive correlation with NDBI by 0.929 and had high positive correlation with impervious area ratio by 0.857. In order to analysis of thermal environment on land use, types of urban area were classified by 4 of residential focus area, industrial focus area, green focus area and mixed area. According to the results of analysis, mean LST of industrial focus area was showed the highest by $21.10^{\circ}C$. But mean LST of green focus area was analyzed the lowest by $18.85^{\circ}C$. In conclusion, the results of this study investigated the effects of spatial characteristics on urban thermal environment and can provide methods and basic informations about land use planning and development density restriction for reduction of urban heat.

Geographic information system (GIS) analysis on the distribution of patients visiting at a dental college hospital: a pilot study (Geographic information system (GIS) 이용한 대학치과병원에 내원하는 환자들의 공간적 분포의 분석)

  • Joo, Hyun-Tae;Jeong, Byung-Joon;Cho, In-Woo;Shin, Hyun-Seung;Lim, Mi-Hwa;Park, Jung-Chul
    • Journal of Dental Rehabilitation and Applied Science
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    • v.31 no.4
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    • pp.283-293
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    • 2015
  • Purpose: The aims of this study are to analyze and to visualize distribution of patients visiting at a dental college hospital, using geographic information system (GIS). The visualized data can be utilized in patient care and treatment planning, ultimately leading to the assessment of risk evaluation and prevention of dental diseases. Materials and Methods: Patient information data was obtained from Dankook University Dental Hospital including the unit number, gender, date of birth, and address from 2007 to 2014. Patient distribution was visualized using GIS. Statistical analyses were performed using SAS 9.3 and ArcGIS 10.1. Five factors including proximity, accessibility, age, gender, and socioeconomic status were investigated as the explanatory variables of the patient distribution. Results: The visualized patient data showed a nationwide scale of the patient distribution. There was a little difference in characteristics for each department. As closer at Dankook University Dental Hospital, visitors increased. And it strongly showed that elderly patients in rural areas tend to visit more. Conclusion: The distribution of patients has been shown to be significantly affected by the proximity, accessibility, age, gender and socioeconomic status. The underlying reason remains to be further studied.

Analysis of Spatial Characteristics of Vacant Houses using Geographic Weighted Regression Model - Focus on Busan Metropolitan City - (지리가중회귀모델을 적용한 빈집 발생의 공간적 특성 분석 - 부산광역시를 대상으로 -)

  • KIM, Ji-Yun;KIM, Ho-Yong
    • Journal of the Korean Association of Geographic Information Studies
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    • v.24 no.1
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    • pp.68-79
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    • 2021
  • The recent occurrence of vacant houses in urban areas is a remarkable social problem. One of the physical declines, the occurrence of vacant houses, accelerates various social and economic declines, such as a decline in population and a slump in the commercial district. Vacant houses have regional characteristics and spatial influence, and it is necessary to approach them locally in order to grasp the exact status of vacant houses. Therefore, in this study, the effect of urban decline on the occurrence of vacant homes was examined by region using global Moran's I and Geographic Weighted Regression(GWR) model. As a result of the analysis, there were spatial autocorrelation and heterogeneity in the occurrence of vacant houses in each eup·myeon·dong, Busan metropolitan city. In addition, there is a difference in the influence of each variable of urban decline on the occurrence of vacant houses, and even the same variable of urban decline has different effects on the occurrence of vacant houses in different regions. Therefore, it is expected that a more efficient vacant home management plan can be presented if the GWR model is used to analyze the coefficient values differentiated by region and categorize the occurrence of vacant houses.

The Impact of a Basic Environmental Facility Siting on Land Prices : A Case of Sewage Disposal Plant (환경기초시설의 입지가 지가에 미치는 영향 : 하수처리장을 사례로)

  • JUN, Byong-Woon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.20 no.3
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    • pp.170-180
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    • 2017
  • This research analyzed the effect of a basic environmental facility siting on the difference in land prices using a case study of Jisan sewage disposal plant in Daegu metropolitan city. To do so, two buffer zones were generated around Jisan sewage disposal plant to 400m at an interval of 200m as a setback distance and 822 officially announced individual land prices were acquired from Korea Ministry of Land, Infrastructure and Transport(MOLIT). Paired samples t-test was performed to compare the mean difference in land prices before and after Jisan sewage disposal plant siting. Results show that the mean land price from each buffer zone was slightly increased after the siting and the difference was statistically significant. Also, the results indicate that the mean land price within 200m was lower than that between 200m and 400m before the siting while there was not different in the mean land price for both buffer zones after the siting. Because Jisan sewage disposal plant did not have a stench and a larger capacity and its surrounding areas were blended by commercial and residential uses, a sewage disposal plant siting had little effect on the fall in land prices unlike previous studies. The findings from this research will provide new reference data for local government and local people with conflicting views on the siting of a basic environmental facility.

Proposal of Prediction Technique for Future Vegetation Information by Climate Change using Satellite Image (위성영상을 이용한 기후변화에 따른 미래 식생정보 예측 기법 제안)

  • Ha, Rim;Shin, Hyung-Jin;Kim, Seong-Joon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.10 no.3
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    • pp.58-69
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    • 2007
  • The vegetation area that occupies 76% in land surface of the earth can give a considerable impact on water resources, environment and ecological system by future climate change. The purpose of this study is to predict future vegetation cover information from NDVI (Normalized Difference Vegetation Index) extracted from satellite images. Current vegetation information was prepared from monthly NDVI (March to November) extracted from NOAA AVHRR (1994 - 2004) and Terra MODIS (2000 - 2004) satellite images. The NDVI values of MODIS for 5 years were 20% higher than those of NOAA. The interrelation between NDVIs and monthly averaged climate factors (daily mean, maximum and minimum temperature, rainfall, sunshine hour, wind velocity, and relative humidity) for 5 river basins of South Korea showed that the monthly NDVIs had high relationship with monthly averaged temperature. By linear regression, the future NDVIs were estimated using the future mean temperature of CCCma CGCM2 A2 and B2 climate change scenario. The future vegetation information by NOAA NDVI showed little difference in peak value of NDVI, but the peak time was shifted from July to August and maintained high NDVIs to October while the present NDVI decrease from September. The future MODIS NDVIs showed about 5% increase comparing with the present NDVIs from July to August.

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