• Title/Summary/Keyword: Land cover

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The Numerical Simulation of Dry Deposition Velocity Of O3 using Land-Use Information in the Busan Metropolitan City (지표면 특성을 고려한 부산지역의 건성침적속도 예측)

  • 문난경;이화운
    • Journal of Environmental Science International
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    • v.11 no.9
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    • pp.925-931
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    • 2002
  • Land-use types should be included in air pollutant diffusion model because a complex mixture of various land-use patterns with computational grid can make errors in calculation of several parameters. However, the air pollutant diffusion model has generally been treated with a uniform component with land-use type in each mesh because of the complexity of the simulation. This study presents a numerical simulation of the horizontal distribution of $O_3$dry deposition velocity during summertime in Busan metropolitan city. The calculation of the meteorological field was conducted using the land cover data. Simulation has been performed by the following two scenarios : (1) one with current land cover data, and (2) the other with only land and sea for the surface characteristics. The results from each scenario reveals considerable differences on the meteorological fields and these differences can cause changes in the calculation values of $O_3$deposition velocity.

Impacts of Urban Land Cover Change on Land Surface Temperature Distribution in Ho Chi Minh City, Vietnam

  • Le, Thi Thu Ha;Nguyen, Van Trung;Pham, Thi Lan;Tong, Thi Huyen Ai;La, Phu Hien
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.39 no.2
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    • pp.113-122
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    • 2021
  • Urban expansion, particularly converting sub-urban areas to residential and commercial land use in metropolitan areas, has been considered as a significant signal of regional economic development. However, this results in urban climate change. One of the key impacts of rapid urbanization on the environment is the effect of UHI (Urban Heat Island). Understanding the effects of urban land cover change on UHI is crucial for improving the ecology and sustainability of cities. This research reports an application of remote sensing data, GIS (Geographic Information Systems) for assessing effects of urban land cover change on the LST (Land Surface Temperature) and heat budget components in Ho Chi Minh City, where is one of the fastest urbanizing region of Vietnam. The change of urban land cover component and LST in the city was derived by using multi-temporal Landsat data for the period of 1998 - 2020. The analysis showed that, from 1998 to 2020 the city had been drastically urbanized into multiple directions, with the urban areas increasing from approximately 125.281 km2 in 1998 to 162.6 km2 in 2007, and 267.2 km2 in 2020, respectively. The results of retrieved LST revealed the radiant temperature for 1998 ranging from 20.2℃ to 31.2℃, while that for 2020 remarkably higher ranging from 22.1℃ to 42.3℃. The results also revealed that given the same percentage of urban land cover components, vegetation area is more effective to reduce the value of LST, meanwhile the impervious surface is the most effective factor to increase the value of the LST.

Runoff Curve Number Estimation for Cover and Treatment Classification of Satellite Image(I): - CN Estimation - (위성영상 피복분류에 대한 CN값 산정(I): - CN값 산정 -)

  • Bae, Deg-Hyo;Lee, Byong-Ju;Jeong, Il-Won
    • Journal of Korea Water Resources Association
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    • v.36 no.6
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    • pp.985-997
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    • 2003
  • The objective of this study is to propose Runoff Curve Numbers(CNs) for land cover and treatment classification of satellite image. For this purpose, land cover classifications by using satellite image in addition to the exiting SCS's land cover and treatment classifications studies and land cover classifications suggested by Ministry of Environment are selected to provide CNs depending on the classifications. CNs estimation method is statistical approach that is suggested by Hjelmfelt(1991). Result of this study may contribute to use efficiently for the estimation of CNs in using satellite image.

Prediction of Urban Land Cover Change Using Multilayer Perceptron and Markov Chain Analysis (다층 퍼셉트론(MLP)과 마코프 체인 분석(MCA)을 이용한 도심지 피복 변화 예측)

  • Bhang, Kon Joon;Sarker, Tanni;Lee, Jin-Duk
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.36 no.2
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    • pp.85-94
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    • 2018
  • The change of land covers in 2026 was prediceted based on the change of urbanization in 1996, 2006 and 2016 in Seoul and surrounding areas in this study. Landsat images were used as the basic data, and MLP (Multilayer Perceptron) and MCA (Markov Chain Analysis) were integrated for future prediction for the study area. The land cover transition potentials were calculated by setting up sub-models in MLP and the driving factors of land cover transition from 1996 to 2006 and transition probabilities were calculated using MCA to generate the land cover map of 2016. This was compared to the land cover map of 2016 from Landsat. MLP and MCA were verified and the future land covers of 2026 were predicted using the land cover map from Landsat in 2006 and 2016. As a result, it was predicted that the major land cover changes from 1996 to 2006 were from Barren Land and Grass Land to Builtup Area, and the same trend of transition will be remained for 2026. This study is meaningful in that it is applied for the first time to predict the future coating change in Seoul and surrounding areas by the MLP-MCA method.

Estimation of Soil Erosion Using National Land Cover Map and USLE (USLE와 국가토지피복지도를 이용한 토양유실 추정)

  • Jeong, JongChul
    • Journal of Environmental Impact Assessment
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    • v.25 no.6
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    • pp.525-531
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    • 2016
  • This study integrates the Universal Soil Loss Equation(USLE) with GIS method to assess the soil erosion for national land cover map between 2007 and 2014. The land cover change map and C factors of USLE were applied to the estimation of spatial distribution of sediment yield. However, they generated distinct results because of differences in their applied methods and calculation processes of national land cover map. To generate the USLE model, C factors of MOE(Ministry of Environment) were compared with soil erosion of Inje stadium development area at the Naerin watershed in Gangwon province to 2014. The several thematic maps of research area such as land cover map, topographic and soil maps, together with tabular precipitation data used for soil erosion calculation. The land cover change were carried with level-2 and high level land cover map of MOE and estimated maximum double of soil erosion.

A Machine learning Approach for Knowledge Base Construction Incorporating GIS Data for land Cover Classification of Landsat ETM+ Image (지식 기반 시스템에서 GIS 자료를 활용하기 위한 기계 학습 기법에 관한 연구 - Landsat ETM+ 영상의 토지 피복 분류를 사례로)

  • Kim, Hwa-Hwan;Ku, Cha-Yang
    • Journal of the Korean Geographical Society
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    • v.43 no.5
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    • pp.761-774
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    • 2008
  • Integration of GIS data and human expert knowledge into digital image processing has long been acknowledged as a necessity to improve remote sensing image analysis. We propose inductive machine learning algorithm for GIS data integration and rule-based classification method for land cover classification. Proposed method is tested with a land cover classification of a Landsat ETM+ multispectral image and GIS data layers including elevation, aspect, slope, distance to water bodies, distance to road network, and population density. Decision trees and production rules for land cover classification are generated by C5.0 inductive machine learning algorithm with 350 stratified random point samples. Production rules are used for land cover classification integrated with unsupervised ISODATA classification. Result shows that GIS data layers such as elevation, distance to water bodies and population density can be effectively integrated for rule-based image classification. Intuitive production rules generated by inductive machine learning are easy to understand. Proposed method demonstrates how various GIS data layers can be integrated with remotely sensed imagery in a framework of knowledge base construction to improve land cover classification.

A Study on the Strategies for Spatial Information Service based on the Concept of Atlas - A Case Study of Land Cover Map - (아틀라스 개념을 적용한 공간정보서비스 방안 - 토지피복지도를 사례로 -)

  • Hong, Sang Ki
    • Journal of Korean Society for Geospatial Information Science
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    • v.20 no.4
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    • pp.153-159
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    • 2012
  • Recently, tthe general users' demand on utilizing spatial information and the establishment of national spatial data such as land cover map are increasingly growing. But the lack of spatial information service for the general public is making it difficult for them to use spatial information and services. In this study, spatial information service strategies based on the concept of atlas, which is familiar to us through the student atlas, were proposed to promote the public users' utilization of land cover map. For this purpose, I reviewed current domestic status and overseas cases of land cover map service and proposed the future direction of spatial information service for land cover map in terms of contents, users, and system. Finally, I defined the basic concept, characteristics and functions of the Atlas Information System and recommended strategies for environmental spatial information service. The results of this study can be applied to various national spatial information as well as land cover map and contribute to the increase of general public users' utilization of national spatial data.

Analysis of the Effect of Differences in Spatial Resolution of Land-use/cover Data on the Simulation of CALPUFF (토지피복 자료의 해상도 차이가 CALPUFF 농도 모의에 미치는 영향 분석)

  • Hwang, Suyeon;Ham, Jungsoo;Lee, Youngjin;Choi, Jinmu
    • Korean Journal of Remote Sensing
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    • v.37 no.5_3
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    • pp.1461-1473
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    • 2021
  • The purpose of this study is to ascertain how the level of resolution of land cover data affects on the local distribution and diffusion of fine dust. the CALPUFF model, which considers the spatio-temporal terrain conditions and changes in weather conditions, was used to estimate PM10 concentration in the Pyeongchon, Anyang-si, Gyeonggi-do. Three different resolutions of land cover data including 20 m, 50 m, and 100 m were compared as the input of the modeling. Using higher resolution land cover data (20 m), the wind speed of the simulated region was the largest and the PM10 concentration was the lowest. Through this study, we confirm that the resolution level of land-use/cover data can affect the local distribution and diffusion of fine dust, which can be detected by CALPUFF. Therefore, when using CALPUFF to simulate fine dust in the future, it can be suggested that checking the impact on spatial resolution according to the form of land cover in advance and proceeding with the simulation can achieve mote accurate results.

A Study on a Landscape Structure as a Change of Impervious Cover Rate in the Osan-cheon Watershed (오산천 유역의 불투수면 비율 변화에 따른 경관구조 분석)

  • Jang, Su Hwan
    • Journal of Environmental Impact Assessment
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    • v.17 no.5
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    • pp.289-297
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    • 2008
  • An impervious cover is one of most important factors which effect on a water body environment in a watershed. There are many researches on the impact of an impervious cover on water quality, quantity and ecosystem and most of these researches have been focused on an impervious rate or area in a watershed without considering structure features as like shape, edge, connection of impervious cover. In this study, we focused on a landscape structure which includes shape, density, contiguity, distance, aggregation of land cover type as well as area and rate. The calculation of a landscape indices made to analyse a landscape structure is conducted by applying Fragastats 3.3 program. Osan-cheon watershed where has rapidly urbanized is selected as a study field. Land information for 2002 and 2007 is from land classification maps provided by Ministry of Environment. The result shows that the increasing rate of an impervious cover is more conspicious in Kiheung dam watershed but the fragment of impervious cover areas is shown remarkably in the Osan sub-watershed. The trend of aggregation and connection of impervious covers is increasing. But it was very difficult to say that which type of landscape structure is more beneficial for a watershed management. The implication of this study is to find the need to come over the conventional ways to evaluate landscape structure of a watershed such as rates and areas of impervious cover, and define the importance of landscape feature as like connection, distance, edge density, fragment of impervious covers.

The study on Decision Tree method to improve land cover classification accuracy of Hyperspectral Image (초분광영상의 토지피복분류 정확도 향상을 위한 Decision Tree 기법 연구)

  • SEO, Jin-Jae;CHO, Gi-Sung;SONG, Jang-Ki
    • Journal of the Korean Association of Geographic Information Studies
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    • v.21 no.3
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    • pp.205-213
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    • 2018
  • Hyperspectral image is more increasing spectral resolution that Multi-spectral image. Because of that, each pixel of the hyperspectral image includes much more information and it is considered the most appropriate technic for land cover classification. but recent research of hyperspectral image is stayed land cover classification of general level. therefore we classified land cover of detail level using ED, SAM, SSS method and made Decision Tree from result of that. As a result, the overall accuracy of general level was improved by 1.68% and the overall accuracy of detail level was improved by 5.56%.