LANDSAT 영상을 이용한 해안선 자동 추출과 변화탐지 모니터링

국문 초록 (Abstract)

지구 온난화와 이로 인한 해수면의 상승은 명백히 전 지구적으로 일어나고 있는 변화이며 해안선의 변화 또한 동반되고 있다. 해안선은 해수면의 상승뿐만 아니라 인위적인 활동에 의해서도 변화할 수 있으나 지구온난화에 의한 해안선 변화의 파악은 지구 온난화의 진행을 파악할 수 있는 지표로써 활용이 가능하다. 따라서 본 연구의 목적은 자동으로 해안선을 추출 및 변화를 파악하는 데에 있다. 본 연구에서는 자동으로 해안선을 추출하기 위해서 수분지수를 활용하여 물과 육지의 대조를 극대화하였으며, 해안선의 자동 추출이 용이하도록 하였다. 수분지수로 변환된 영상에서 자동으로 물과 육지를 분할하기 위하여 적정 임계값을 자동으로 찾을 수 있도록 영상처리 기법을 적용하였고, 경계선 검출 알고리즘을 통하여 해안선을 추출하였으며 추출된 해안선으로 변화를 탐지하는 방법론을 제시하고자 하였다. 자동으로 물과 육지를 분할하고 경계선을 찾는 영상처리 기법은 다른 자료의 도움 없이 LANDSAT 영상만을 이용하여 적용될 수 있으며 추출된 해안선 또한 기준자료로 이용된 NLCD(National Land Cover Database) 자료와의 비교를 통해 유사하다는 것을 확인할 수 있었다. 또한 지구 온난화의 지표로써의 활용가치를 확인하기 위해 연구 대상지역을 지층의 온도가 연중 0℃ 이하로 항상 얼어 있는 영구동토로 선정하여 영구동토의 해빙으로 인한 해안선 변화를 정량적으로 확인할 수 있었으며 해안선의 변화가 가속화한다는 사실을 확인할 수 있었다.

다국어 초록 (Multilingual Abstract)

Global warming causes sea levels to rise and global changes apparently taking place including coastline changes. Coastline change due to sea level rise is also one of the most significant phenomena affected by global climate change. Accordingly, Coastline change detection can be utilized as an indicator of representing global climate change. Generally, Coastline change has happened mainly because of not only sea level rise but also artificial factor that is reclaimed land development by mud flat reclamation. However, Arctic coastal areas have been experienced serious change mostly due to sea level rise rather than other factors. The purposes of this study are automatic extraction of coastline and identifying change. In this study, in order to extract coastline automatically, contrast of the water and the land was maximized utilizing modified NDWI(Normalized Difference Water Index) and it made automatic extraction of coastline possibile. The imagery converted into modified NDWI were applied image processing techniques in order that appropriate threshold value can be found automatically to separate the water and land. Then the coastline was extracted through edge detection algorithm and changes were detected using extracted coastlines. Without the help of other data, automatic extraction of coastlines using LANDSAT was possible and similarity was found by comparing NLCD data as a reference data. Also, the results of the study area that is permafrost always frozen below 0 ℃ showed quantitative changes of the coastline and verified that the change was accelerated.

목차 (Table of Contents)

• 要旨
• Abstract
• 1. 서론
• 2. 연구대상지역
• 3. 해안선의 추출 방법
• 4. 결론
• References

참고문헌 (Reference)

1 Ilsever, M., "Two-Dimensional Change Detection Methods: Remote Sensing Applications (SpringerBriefs in Computer Science)" Springer 2012

2 McFeeters, S.K., "The use of the Normalized Difference Water Index (NDWI) in the delineation of open water features" 17 (17): 1425-1432, 1996

3 Mars, J.C., "Quantitative remote sensing study indicates doubling of coastal erosion rate in past 50 yr along a segment of the Arctic coast of Alaska" 35 (35): 583-586, 2007

4 Bruce, C.M., "Pre-processing Methodology for Application to Landsat TM/ETM+ Imagery of the Wet Tropics" CSIRO Tropical Forest Research Centre and Rainforest CRC 2006

5 MRLC, "National Land Cover Database 2001"

6 Xu, H., "Modification of normalised difference water index (NDWI) to enhance open water features in remotely sensed imagery" 27 (27): 3025-3033, 2006

7 NASA, "Landsat 7 Science Data Users Handbook"

8 Silver, J., "Global Warming and Climate Change Demystified" McGraw Hill Professional 2008

9 Mars, J.C., "Digital-Elevation and Surface-Classification Maps of the Fish Creek Area, Harrison Bay Quadrangle, Northern Alaska" U.S. Geological Survey 2005

10 Lee, J.S., "Coastline Detection and Tracing in SAR images" 28 (28): 662-668, 1990

11 IPCC, "Climate Change 2007: The physical science basis. Contribution of working group I to the forth assessment report of the Intergovernmental Panel on Climate Change" Cambridge University Press 2007

12 Pardo-Pascual, J.E., "Automatic extraction of shorelines from Landsat TM and ETM+ multi-temporal images with subpixel precision" 123 : 1-11, 2012

13 Liu, H., "Automated extraction of coastline from satellite imagery by integrating Canny edge detection and locally adaptive thresholding methods" 25 (25): 937-958, 2004

14 Zhang X., "Automated detection of coastline using Landsat TM based on water index and edge detection methods" 2012

15 Qiao, C., "An Adaptive Water Extraction Method from Remote Sensing Image Based on NDWI" 40 (40): 421-433, 2012

16 Institute of Arctic and Alpine Research, "Alaskan Coastal Erosion"

17 Ouma, Y. O., "A water index for rapid mapping of shoreline changes of five East African Rift Valley lakes: an empirical analysis using Landsat TM and ETM+ data" 27 (27): 3153-3181, 2006

18 Choi, Y., "A study on a face recognition and a performance comparison by Threshold change of Canny edge operator" Graduate school of Information Contents, Kwanwoon University 2007

19 Heo, J., "A new methodology for measuring coastline recession using buffering and non-linear least squares estimation" 23 (23): 1165-1177, 2009