At the end of May 2014, UPVISION, a Czech UAV company, conducted a UAV survey of a landslide on Highway D8, near the city of Litomerice,in the northern part of the Czech Republic. A geological survey was conducted on Highway D8, which had been under construction at the time of the landslide.
Utilizing the results of the geological survey, which draws upon the work from the UAV mapping exercise, engineers will decide how to remove the landslide debris and ensure against any other landslides in the future. Alternative options are also under consideration, such as constructing a tunnel.
Figure 1. Oblique image landslide (click for larger image)
The Landslide Area
The landslide buried the D8 highway on June 7, 2013 after heavy rains in Litochovice village, near the city of Litomerice.
Highway D8 connects Prague with the northwest Czech agglomerations and Saxony in Germany. Vehicular traffic exceeds 10,000 cars per day with heavy traffic through the cities of Usti, Labem and Teplice. The landslideoccurred in hilly terrain along the highway, between a quarry at the top of the hill and flowing down toward the River Elbe. The landslide measured 500 by 200 meters and wiped out the exiting terrain, trees, active railroad tracks, and of course the existing highway structure.
Mapping the Area with UAVs
UPVISION’shexacopter unmanned aerial vehicle (UAV) was usedto map the landslide site, which measured2 km². In addition, aerial photographs and video of the landslide area were captured, including the adjacent quarry. From these data, several image products were created: 1) an orthophoto map with 7 cm/pixel image resolution in the local geographic system; 2) a digital surface model using point clouds and; 3) 3D model for visualizing the entire area.
These complex data visualizations, in addition to the actual photographic images, can be used for technical applications such as vectorization to create digital maps, calculations of the landslide volume, terrain profiles, point clouds in high definition, and also as a basis for the geological surveys.
All these data can be obtained from one, short unmanned aerial flight, which is launched directly over the destination area and within one hour the field work can be completed.
Additionally, you canwatch online video streaming the extent of the terrain immediately after the collapse of the landslide.
The actual mapping UAV is a very effective tool for obtaining complex data with a focus on speed and efficiency. The dataoutputs can be used for documentation and status updates, as well as technical documentation and visualization.
Figure 2. 3D points cloud (click for larger image)
Figure 3. UPVISION’s uniquely-designed UAV (click for larger image)
Figure 4. Orthophotomap at 7 cm/px resolution (click for larger image)
Figure 5. Digital elevation model (click for larger image)
Figure 6. Hexacopter pilot and operator (Jakub Karas, UAS manager – on the left)