This document summarizes a study that monitored topographic changes in a coastal area using remote sensing data and digital elevation models from 2002-2010. The study area was located near the Nakdong River Estuary Barrage, which was constructed in 1987 and altered sedimentation patterns in the region. Landsat and aerial imagery were used to map changes in shorelines and sandbars over time. Digital elevation models generated from aerial and terrestrial lidar surveys in 2008 and 2010 were differenced to identify areas of erosion and sedimentation. Preliminary results found changes to sandbar positions and sedimentation rates downstream of the Nakdong River Estuary Barrage after its construction.

1. Monitoring of topographic change on the coastal area Jinah Eom1,2, Jong-Kuk Choi1, Joo-Hyung Ryu1, Joong-Sun Won2 1 Korea Ocean Satellite Center, Korea Ocean Research & Development Institute (jina9003@kordi.re.kr) 2 Department of Earth System Sciences, Yonsei University

2. Contents 1. Introduction & Objective 2. Study area 3. Data & Method 4. Results 5. Conclusion

3. 1. Introduction

4. 1. Introduction Since the 1980’s, a series of construction projects for land reclamation have been carried out on a large scale in western sea Land reclamation combined with the dynamics of tidal currents accelerated local sedimentation and erosion, resulting in the fast reformation of intertidal topography For this reason, Lee et al (2006), Ryu et al (2008), and so on were carried out monitoring of tidal flat topography using Digital Elevation Model (Lee et al, 2011)

7. 1. Introduction The importance of the east sea to key industries, such as nuclear power plants, shipyards, and cement production, and to a lesser extent the fishing and leisure industries, is gradually increasing However, coastal erosion in east sea is being accelerated so that the size of the sandy beach is being reduced abruptly along with a lots of other places including Jugbyeon, Bongpyeong beach, Sanpo-ri, Weonnam, Osan, Deogsin, and Hupo in Uljin-gun.

8. Objective In this study Final goal

9. 2. Study area

10. 3. Data Remotely sensed data Change of sandbar : used Landsat ETM+ image from 2002 to 2010 Monitoring of shoreline change : used aerial photograph, IKONOS, KOMPSAT-1/2 from 1971 to 2009 Monitoring of topography : used aerial LiDAR data and terrestrial LiDAR at 2008, 2010 In situ data – used DGPS Date : May. 2008., Jun. 2010 For comparison with Lidar data

11. Location of 2nd grade measurement survey benchmarks within KORDI-ESRI

13. Method – LiDAR DEM LiDAR – generated DEM data DEMchange = DEM2008 – DEM2010 DEMchange: topographical change DEM2008 : topographical height in 2008 DEM2010 : topographical height in 2010 Positive : represents erosion Negative : sedimentation

15. After that, current rate and sedimentation rate were changed

16. Nakdong river is a major source of sedimentation of sandbar

17. Tide height 2003.11.02 : 68 cm 2010.11.05 : 71 cm