River embankment repair measurements on a Hydropower Plant in Boštanj

For a client, the Slovenian National Building and Civil Engineering Institute (ZAG), we performed photogrammetric measurements on a 400-meter stretch of the Sava river embankment. The canal is part of the Hydropower Plant (HPP) Boštanj, located a few hundred meters downstream. 

High water levels and an increased water flow at heavy rainfalls damaged the river embankment that leads down to the HPP. The objective was to map the already rehabilitated section of the bank as well as damaged parts and generate 2D and 3D geo-referenced models that would later serve as the basis for further reconstruction and repair projects.

We flew our DJI drone to the altitude of 40 meters to capture high- resolution images. We set the image overlap to 60% horizontal and 75% vertical. Positioning accuracy was achieved through 10 ground control points we placed using GPS.

The embankment itself was in some places steep and eroded. Details required for a successful completion of our project were difficult to acquire through vertical aerial photography alone. We had to take a series of images of the bank at an angle and that helped us get the textures and details we needed to properly document the situation. 

It was a beautiful sunny winter day but we still processed our data from the comfort of our office and let 3Dsurvey do all the hard work. 

Check out the gallery for some of the photos of the area and screenshots of 3D models we’ve been able to create purely from images. Drone-based mapping and photogrammetry again proved to be the right approach.

Tools: DJI S900 drone at 40m altitude, Olympus EPL7 
Positioning: GPS used to place Ground control points
Software: 3Dsurvey