| LIDAR AND PHOTOGRAMMETRY APPROACHES FOR MONITORING LAND SURFACE MORPHOLOGY IN EPHEMERAL GULLY SYSTEM |
| Paper ID : 1138-SMPR |
| Authors: |
|
Ximeng Xu * Institute of Geographic Sciences and Natural Resources Research,
Chinese Academy of Sciences，Beijing，PR China |
| Abstract: |
| Based on the long-term field investigation on the land surface morphology in ephemeral gully system, LIDAR and photogrammetry techniques were used to quantify the morphology dynamics in ephemeral gully system. The LIDAR monitoring results showed that ephemeral gully occurred in the same location on the slope surface after every rainy season in the ephemeral gully system, then lateral topsoil was tilled and brought into the ephemeral gully channel, inducing 2 cm decrement around channel before rainy season of next year, which make it a cycle of erosion-tillage-erosion. During this process, imbricated landform was formed to a ephemeral gully system. The photogrammetry monitoring results showed that most drop-sills distances in ephemeral gully channel were in 10 to 25 cm, while slope gradients were among 15° to 40°. drop-sills distance and slope gradient shoed negative exponent relationship. The results of this study showed that LIDAR technology can quickly acquire the topographic characteristics of the whole ephemeral gully system, while photogrammetry method could make up this disadvantage and quickly acquire detailed ephemeral gully channel morphology. |
| Keywords: |
| Point cloud, Laser scanning, Morphology dynamics, Cross section, Hilly-gully region, Headcuts |
| Status : Conditional Accept (Oral Presentation) |
