Challenge

As part of the ongoing management of the Norfolk coastline, the Borough Council of King’s Lynn & West Norfolk instructed Wide Horizons UAV (drone) surveying team to assist them in capturing accurate, usable data which could be actively utilised to track erosion, debris and overall changes along a section of Norfolk’s coastal cliffs. Historically, measurements had been taken at ground level using existing features as datums to review cliff erosion levels, this method proved to be inconsistent due to a number of factors such as human error and varied interpretations of datum points. Wide Horizons was required to provide a solution which would prove reliable and ensure usable information was available for the cliff edge in relation to the datum points inland as well as information showing the debris amount and size along the cliff apron.

Solution

With the objectives set, the Wide Horizons drone team proposed to capture the data by creating georeferenced orthorectified maps. This survey provided high-resolution imagery of the cliff plan which was then geometrically corrected to ensure that the scale was uniform to that of a map. The orthorectified map was then used to measure the true distance of the cliffs' erosion rate, as well as debris amount, size and movement when evaluated with existing and future data. Furthermore, the orthomosaic map was compatible with standard GIS platforms and so could be integrated into the clients existing software for ease of usability. The project was completed after extensive prior planning with the client to ensure minimal disruption to residents and members of the public and to ensure safe operation of the drones during the surveys. Once all preparation was complete, the surveys were then carried out using an experienced RPAS team, utilising pre-agreed launch locations and pre-planned flight paths to ensure efficiency, reliability and safety.

Results

The project resulted in the successful creation of highly accurate mapping data which was able to provide accurate measurements to actively manage and understand the erosion and debris levels along the cliff area. Furthermore, due to the use of aerial platforms to conduct the survey, the project was completed with a considerable time saving compared to traditional methods.

Back to case studies