East Yorkshire coastal erosion

aerial (satellite) imagery





This page briefly describes the main sources of aerial, specifically satellite, imagery used in the preparation of East Yorkshire coastal erosion pages, and for ongoing studies.

Images captured by satellite and made available online inevitably show the coastline as it was at some earlier moment in time. In images of relatively recent date, there may be no or very little difference from the present situation at a number of locations. Older images provide an idea of how much cliff can be lost over a period.

Pr = monitoring profile (see data summary)



 
UK Grid Reference Finder–Apple

direct link

UKGRF-Apple is an ideal tool for quick access to a particular point on the coastal map when a coordinate is known.

Three types of coordinates are recognised. Grid Reference, the National Grid system employed in all Ordnance Survey maps, is preferred because only one element is needed in place of an easting then a northing, or latitude and longitude.

A copy/paste from the coordinates full spreadsheet or fieldwork spreadsheet into the Grid Reference search box at the left of the UKGRF map will zoom in to a required monitoring location. For example, the entry TA 25574 39697 directs the view to the cliff intersect for Profile 62 at Aldbrough.

Where a coordinate is not known then manual zoom can be applied. There are icons for the usual mapping tools.

Imagery dates are not given.


why Apple?

Formerly, UK Grid Reference Finder was powered by Google Earth. The following text from the Finder site’s FAQ page explains the circumstances.

“Unfortunately Google have vastly increaded the cost of their maps, at short notice, which made it impossible for us to continue to use as a free service. We will be bringing the Google maps facility back in the future but as a paid service (this is the only way we can do this unfortunately) for those who need them.

“Our base map continues to be free but bear with us while we implement our new Apple maps in a very short period of time.”


Batch Convert Tool

direct link

As the name implies, the Batch Tool facilitates multiple coordinates to be inserted in a single process.

Echoing the earlier example, a block of coordinates will copy/paste from the coordinates full spreadsheet or fieldwork spreadsheet into the Batch Tool search box (Step One).

Assuming that the selected coordinates are in National Grid format, check the Grid Reference button in Step Two. Then press Convert (Step Five) and Show Points on a Main Map (Step Seven).

The Main Map in this case is the Apple map. If the tool does not work correctly, try another browser.



 
UK Grid Reference Finder–Bing

direct link

UKGRF-Bing is an older version. The display is labelled Aerial rather than Satellite. It does not expand to full screen.



 
Google Earth

Pins Pr1 to Pr123 mark cliff top positions of monitoring profiles, the current system of measuring cliff loss.

Profiles notionally extend from a point inland to one at sea. Length is about 1.3 kilometres. On the GE image, length is reduced to 50 metres, this being landward and seaward extentions of 25 metres from cliff top intersects as they were in 2014-2015.

Pins EP1 to EP120 mark locations of erosion posts, the previous system of measuring cliff loss.

See data-in-detail for background.


data check

Also appearing with profile markings on the GE map are dots in circles. These indicate cliff top intersects in 2003, the year when systematic regular monitoring of cliff loss for the entire coast was introduced.

Positions for the dots are calculated from data. Losses are added together and the distance extended seaward along the profile from a later intersect.

The Google Earth Pro Show historical imagery feature (icon in the top toolbar and time slider) includes a map of the coastline for 2003.

In general there is agreement between imagery and calculation, with examples of precise alignment. Of the exceptions, alignment might be seen at a later acquisition date, e.g. 2005 or 2007.


most recent dates

Google Earth satellite imagery receives regular updates. In terms of resolution and quality, some are better than others. Positions are approximate.

from Pr1 to north of Bridlington Harbour
15 April 2021

from north of Bridlington Harbour to 36 metres south of Pr41
17 March 2021

from 36 metres south of Pr41 to 170 metres south of Pr51
16 April 2020

from 170 metres south of Pr51 to 182 metres north of Pr117
22 April 2021

from 182 metres north of Pr117 to end of coast
21 September 2019



 
Channel Coastal Observatory

direct link

Aerial maps are accessed by View Layers (sandwich icon) then Ortho-rectified photography. Frames in the CCO application can be slow to resolve but images are of good quality and purposely depict the beach at low tide, useful for observing sediment configurations. Long/Lat coordinates are provided in the top right corner. Dates available are 2012, 2011, 2010, 2009.

Also on the layers menu are annual continuous cliff lines from 2018 back to 2003, possibly the only such set available online, as well as some (not particularly useful) Lidar elevations.




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Prepared by Brian Williams in April 2019. Last update 30 June 2021.