FME World Tour UK 2020

FME World Tour UK – 6th May: Nothing is ever simple - grouping historical land use data (Groundsure)

Groundsure provides environmental data and conveyancing reports that are heavily reliant on historical data. One of our most important assets is the Historical Land Use Database (HLUD). The HLUD is derived from historical Ordnance Survey maps. A team of people looked at each map in isolation, drew around important features and logged the land use. The trouble is that you can have the same feature identified multiple times, once for each map that it appears on. So if you have a soup and bone works (that's a real thing) that's present from the 1850s right through to the 1950s, it could appear on five maps in that time. You then get five slightly different looking features with different dates. Display lots of features on a map at once and it can be overwhelming. List those features in a table and you'll get reams of information. The task was to group similar features together, dissolve their geometries, and attribute them with an earliest and latest date.

Simple, right? FME could do that easily. Of course, it was not that simple. Although these features might represent the same site over time, the extents of that site may have changed. If a works doubled in size over ten years, that might be significant to our clients. So you make sure that all the features in each group actually belong there or elsewhere. Sometimes a feature genuinely disappears and reappears; say a tank gets taken out and replaced with a new one. We don't want to suggest the feature is continuous if there's evidence that it's not. So we check our group against its source maps. With this level of complexity, how do you process this volume of data for the whole of the UK? And how do you keep it tidy so others can understand, maintain, and develop it in the future?

This webinar is part of our free FME education programme where we focus on one specific topic and dive deep under the covers to highlight a particular data challenge or solution. All of our historic webinars are published on www.youtube.com/1spatialgroup just in case you missed a session.

In the meantime if you have any technical questions, or you’d just like a quotation for FME, some training or a dedicated consultancy session from one of our FME Certified Professionals, just send us some details to fme@1spatial.com and we’ll be sure to get back to you.