Volume IV-2/W4
ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci., IV-2/W4, 139-147, 2017
https://doi.org/10.5194/isprs-annals-IV-2-W4-139-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 4.0 License.
ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci., IV-2/W4, 139-147, 2017
https://doi.org/10.5194/isprs-annals-IV-2-W4-139-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 4.0 License.

  13 Sep 2017

13 Sep 2017

CHANGE ANALYSIS OF LASER SCANS OF LABORATORY ROCK SLOPES SUBJECT TO WAVE ATTACK TESTING

Y. Shen1,2, R. Lindenbergh2, B. Hofland3, and R. Kramer3 Y. Shen et al.
  • 1School of Earth Science and Engineering, Hohai University, No.1, Xikang Road, Nanjing 210098, China
  • 2Department of Geoscience and Remote Sensing, Delft University of Technology, Stevinweg 1, 2628 CN, Delft, the Netherlands
  • 3Department of Hydraulic Engineering, Delft University of Technology, Stevinweg 1, 2628 CN, Delft, the Netherlands

Keywords: Coastal Engineering, TLS, Change Analysis, Water Flume, Wave Attack, Breakwater

Abstract. For better understanding how coastal structures with gentle slopes behave during high energy events, a wave attack experiment representing a storm of 3000 waves was performed in a flume facility. Two setups with different steepness of slope were compared under the same conditions. In order to quantify changes in the rock slopes after the wave attack, a terrestrial laser scanner was used to obtain 3D coordinates of the rock surface before and after each experiment. Next, through a series of processing steps, the point clouds were converted to a suitable 2D raster for change analysis. This allowed to estimate detailed and quantitative change information. The results indicate that the area around the artificial coast line, defined as the intersection between sloped surface and wave surface, is most strongly affected by wave attacks. As the distances from the sloped surface to the waves are shorter, changes for the mildly sloped surface, slope 1 (1 : 10), are distributed over a larger area compared to the changes for the more steeply sloped surface, slope 2 (1 : 5). The results of this experiment show that terrestrial laser scanning is an effective and feasible method for change analysis of rock slopes in a laboratory setting. Most striking results from a process point of view is that the transport direction of the rocks change between the two different slopes: from seaward transport for the steeper slope to landward transport for the milder slope.