G07 Geohazards Monitoring

IAG (Geodesy)



26-Jun-2015, 15:00 - 16:30


 
Abstract content:

Quality assessment of airborne laser scanning data for landslide study in forested areas

LiDAR technology has become recently a standard tool used for detection, mapping and monitoring of landslide areas, especially in forested or difficult to access regions. The activity of landslides can be monitored by employing the multi-temporal Airborne Laser Scanning (ALS). This requires data collection at a certain time according to the landslide activity what does not always match the optimal period for performing the scanning. The intense vegetation has the significant impact on the quality of point clouds and subsequent products used in landslide studies.
This work assesses the quality of ALS data collected for landslide studies. The investigation was carried out for the study area of about 40 km2 located at the edge of Roznow Lake (Poland). The scanning was performed two times: first on the beginning of April, and then in July 2010; both times using the same Riegl LiteMapper laser scanning system operating with the same parameters. ALS data accuracy was estimated by comparing it with the reference data collected directly in the field using GNSS technology.
Results obtained for two data sets showed significant quality decrease for the period of intense vegetation; for example, in forested areas the vertical accuracy of ALS data has changed from 0.19 m in April to 0.74 m in July. Moreover, the density of terrain points significantly decreased (up to 30%) in the latter period. This caused that the scanning performed in July was not fully valuable in determining the amount of displaced landslide material. Beside the quality assessment of the ALS data, this work also discusses the accuracy of estimated volume of the relocated landslide material.

 
Author(s):
A. Borkowski1, G. Józków2, M. Ziaja1.
1Wroclaw University of Environmental and Life Sciences, Institute of Geodesy and Geoinformatics, Wroclaw, Poland.
2The Ohio State University, Department of Civil- Environmental and Geodetic Engineering, Columbus, USA.

 

Keywords:
LiDAR     airborne laser scanning     accuracy     landslide     forested area