Choosing a field site: A photogrammetrist’s view (Part two)

The idea of a colourful coastal cliff seemed well fleshed out and rational, so I honed in on my options. Short of Devon, Seven Sisters near Brighton seemed like a natural choice. Having gone there on a fieldtrip which was included in one of my first blog posts, it is quite iconic with a good scale range available at different parts of the coast. The downsides include the tricky access, coarse grain beaches (instability!) and exposure to the elements – there is no hiding on the south coast!

A second fieldtrip in the department posed an interesting opportunity to investigate options in Norfolk. Norfolk, to paraphrase my supervisor (who was quoting someone else), is ‘incredibly flat’. Good for accessibility in that case!

On one of the days, the student’s on the field course were assigned a task, so I ducked away on a reconnaissance mission to Cromer, a coastal town inside the area of outstanding natural beauty in Norfolk. We headed out to the beach, a popular surf spot, to have a look at how appropriate it would be for imaging. The cliff itself wasn’t perfect (heavily vegetated and shallow sloped), the level of the tide would have rendered it almost impossible to conduct a study on the beach. There were coastal defences located in awkward positions which would have limited our freedom of where to image, and it was also quite busy. It wasn’t quite what we were looking for, but looking up and down the coastline, we could see the potential.

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Coastal defences typical of the Norfolk coast

Thus, we headed a ways down the coast to Overstrand, a smaller town with good access to other parts of the coastline. Here we were in luck. A quick peek at an aerial image (Courtesy of GetMapping) reveals some interesting landslide features, and more coastal defences.

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An overview of Overstrand town (Towards the top left) and the cliffs

Thankfully, when we arrived down at the beach, we realised the coastal defences were set back far enough that from a surveying perspective they would not be an issue.

A search established the conservation status of the cliffs, which would likely become convenient later on, as there was likely some literature on their history. Indeed, there are a smattering of papers on modelling the effects of climate change on the coast, geological surveys of the cliffs and effects of coastal protection on their erosion, to give a few examples. The short site description pretty much fits the bill as per part one of this blog series – ‘vegetated, soft cliffs with ruderal plant communities developing on newly exposed sands’. The colour contrast was quite good, with golden sands contrasting the muddier upper portions and partial vegetation. It included an interesting gully feature also, which would undoubtedly push the photogrammetric software to its limits.

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The gully bisecting the survey site

So, a good potential for a site! However, in an ideal world we would have two sites to study in order to demonstrate the variables we are testing in independent cases. Thus, we added access to a second site to our selection criteria and started planning to do both surveys on back to back days over a weekend. However, one site was still lacking, so it was back to looking at good potentials within a reasonable distance of Overstrand.

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