Cliff Erosion: a Global Issue
In 2012, nine homes in Happisburgh, an historic village on England’s Norfolk coast, had to be knocked down after the road on which they were built, started to crumble away into the sea. In July 2013, in St Jouin Bruneval, Normandy, an estimated 30,000 tons of rock split from the 50-meter-high cliffs near the French city of Le Havre and plunged onto the public beach below. In June 2016, huge waves and king tides eroded about 50 meters of the Narrabeen and Collaroy beaches in Sydney, Australia badly damaging waterfront properties and putting them at risk of toppling into the sea. This October, in East-Sussex, England, thousands of tons of chalk crumbled away from the Seven Sisters cliffs at Birling Gap, followed a few days later by another large cliff fall at Seaford Head.
Answers Urgently Needed
Researchers studying this erosion of coastal cliffs in Normandy needed to capture images of these hard-to-reach and unsafe landscapes. The operational challenges included strong winds, limi-ted time windows with optimal lighting, and safety concerns due to operating in an urban environment, which deman-ded high positioning accuracy. They turned to AltiGator, who equipped their OnyxStar XENA drone (UAV) with a Septentrio high-accuracy GNSS receiver and a Sony digital camera, to create the ideal airborne platform capable of collecting excellent results.