Our GIS & Visualisation team will shortly begin to prepare a number of ZTV (Zone of Theoretical Visibility) maps and Photomontages as part of an assessment to consider the potential visibility of High Speed 2 Rail route (HS2) proposals from The National Trust property at Nostell Priory in West Yorkshire.

This builds on similar work which was prepared earlier this year for two other National Trust properties – Shugborough Hall in Staffordshire and Dunham Massey in Cheshire.

The work at Shugborough was the first occasion where we decided to run the ZTV maps using the newly available LiDAR Open Data while running supplementary ZTV maps with Ordnance Survey Terrain 5 data.

The LiDAR Digital Surface Model (DMS) height data includes trees, hedges and buildings etc. which can obstruct visibility while the OS Terrain 5 is a bare digital terrain model (DTM) which does not take account of any vegetation or built structures.

By using two different topographical datasets the resulting maps proved useful in demonstrating the likely degree of visibility of the HS2 line within the existing landscape scenario and also a theoretical ‘worst case’ scenario if views were opened up due to the removal of buildings or trees.

Additionally, and informed by the ZTV results, we carried out summer and winter photography from a number of locations in and around The National Trust properties and produced visualisations from a 3D digital model. The visualisations demonstrate the location and degree of visibility of the current HS2 line route proposals from important and/or sensitive viewpoints using baseline photography showing trees with and without leaf cover.

We believe our considered approach continues to provide The National Trust with an accurate and informative assessment of the potential visual effects of the HS2 proposals and our team looks forward to applying our expertise to further opportunities within the Heritage sector.