East Yorkshire coastal erosion

aerial (satellite) imagery





This page briefly describes the 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 close 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.


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.


Apple map approximate dates

from Pr1 to a point 112 metres north of Pr23
spring to autumn 2012, hazy

from a point 112 metres north of Pr23 to Pr34
similar to above, better quality

from Pr34 to Pr38
2015

from Pr38 to end of coast
similar to above

from Waxholme/Withernsea to end of coast
as above, slightly poorer quality



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.


Bing map approximate dates

from Pr1 to a point 211 metres south of Pr12
autumn 2011, poor quality

from a point 211 metres south of Pr12 to a point 175 metres south of Pr22
as the Apple map, i.e. 2012

from a point 175 metres south of Pr22 to a point 170 metres south of Pr46
2012

from a point 170 metres south of Pr46 to south end of Withernsea seawall
similar to above

from south end of Withernsea seawall to end of coast
similar to above, slightly poorer quality



Google Earth Pro

uploaded link (kml/kmz file)

The map opened by the link shows additions to Google Earth using a Keyhole Markup Language zipped file. These additions are locations of monitoring profiles (Pr) and erosion posts (EP). Monitoring profiles represent the current system of measuring cliff loss, and erosion posts the previous system. See data-in-detail for background.

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.


Google Earth Pro dates

from Pr1 to Pr54 (Grange Farm site, Cowden)
1 July 2018

from Pr54 to Pr122
18 June 2017


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 the latest 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, some explanatory interpretation is possible (alignment might be seen at a later acquisition date, e.g. 2005 or 2007).



Channel Coastal Observatory

direct link

The CCO application can be a little awkward to use (zoom is slow to resolve) but the images purposely depict the beach at low tide, potentially useful for observing sediment configurations. A Dual Map Viewer is available. Dates are 2012, 2011, 2010, 2009.


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Prepared by Brian Williams in April 2019.