Into year 2020 & news of lidar

Into the New Year we go with our first meeting of 2020 taking place tomorrow night at Blythe Way Community Room (off Stocks Lane), Gamlingay. Postcode is SG19 3EH if you need a SatNav thingy. We meet at 7.30pm, all welcome.

While we’re here, let’s talk about lidar. More and more sites are being discovered and known sites better understood as a result of careful scrutiny of lidar derived imagery. It’s a game-changer for archaeology generally and landscape archaeology in particular as we can prospect for sites, find new ones, add to the understanding of known sites and model the terrain the sites are situated within. We have a growing source of freely available lidar data courtesy of the government ‘Open Data’ initiative and it has certainly been a help to us here at GamArch.

However, survey coverage is patchy. This is because the national lidar data survey itself originated out of a need for understanding of flood risks so as to be able to better prepare for and avert flooding: surveys therefore focused on waterways and water catchments, minor streams and watery places – areas away from watery places were therefore left off the lidar survey.

Currently the survey has covered and released lidar data for about half of England. Wales, Scotland and Northern Ireland will have their own data and ways of releasing it. We are fortunate in Gamlingay in having quite a lot of the parish covered but not all of it and for our neighbours in Hatley there’s nothing as yet.

Until recently it wasn’t at all easy finding out when and where the ‘blanks’ on the lidar map might be filled in. Now, the Environment Agency (they are in charge of the surveys) have released an online interactive flat map of their planned and past surveys. By default the map will open on planned survey areas for the coming year – the lidar survey year starts round about now and ends when the trees come into leaf, the leaves muzz up the data collection and so it’s not possible to survey beyond Spring.

If you zoom in on the EA map you’ll see poor old Hatleys will remain marooned, isolated from their friends in lidar surveyed England – a little like Gamlingay is isolated from the wider public footpaths outside the parish. Some of the blanks for Gamlingay may disappear though and there should be better coverage of Everton, Potton and Tempsford. So, we can look forward to a more homogenous lidar map as and when the new data is released later in the ‘lidar year’. Which reminds us, have a very good human year for 2020, all the best to you.