ASSESSMENT OF LANDFORM CHANGES IN BARAMARAE TIDAL FLAT, KOREA USING COMBINED ANALYSIS OF MULTI-TEMPORAL REMOTE SENSING IMAGES AND GRAIN SIZE MEASUREMENT DATA

摘要

In this study, information on landform change in Baramarae tidal flat, Korea is analyzed using multi-temporal Landsat images and grain size measurement data. Unlike previous studies that focused on the extraction of topographic changes from intertidal digital elevation models (DEMs), information on landform change is assessed in the present study by considering both topography and surface sediment characteristics. DEMs in 2000 and 2010 were first generated using waterlines extracted from 16 Landsat images. Mean grain size distribution maps were also generated by interpolating sample data acquired in the field in 2002 and 2012. The non-spatial and spatial characteristics of the landform change in the study area were then analyzed using contingency table plots and difference maps, respectively. Overall sedimentation and coarsening of surface sediments caused by different local marine energy environments were dominant in the study area during the 10-year period. The combined analysis also revealed a close relationship between the changes in topography and grain size. Sedimentation was dominant mainly in areas with fine-grained sediments, while a coarsening trend in the sediments increased with elevation. Moreover, it was possible to locate specific areas in which erosion and a fining trend of surface sediments were observed, which differed from the overall trend of change in the study area. These case study results indicate that the combined analysis of both topography and surface sediment characteristics is very useful in the exploration and monitoring of landform changes in tidal flats.