TVERC Habitat data

Section 41 Habitats of Principle Importance are UK wildlife habitats protected from harmful development by the NERC Act and the National Planning Policy Framework. They should therefore be considered when planning development work.

TVERC has mapped S41 Habitats of Principal Importance in Berkshire and Oxfordshire using a mixture of field survey data and aerial photograph interpretation. The dataset is very high resolution, with polygon boundaries representing on-the-ground habitat boundaries as closely as possible. Areas of rare habitat as small as 0.1 hectares [1,000 m²] are mapped.

Natural England also provides an openly available dataset containing information on Section 41 Habitats of Principle Importance which is available to download from their website. This dataset is far less accurate than the TVERC habitats dataset for Berkshire and Oxfordshire and is not suitable for making decisions at a local level. 11 of the S41 Habitat types are completely missing from the Natural England dataset despite being present in the county and mapped in the TVERC dataset. The resolution of mapping used by Natural England is much lower, with any areas of habitat that do not cover greater than 50% of the extent of an Ordnance Survey MasterMap polygon not being mapped. An analysis comparing the two datasets has shown that this results in an overestimate of the areas of more widespread habitats that tend to occur in larger patches, and an underestimate of rarer habitats that tend to occur in small patches. Some results of this analysis can be seen below.

Section 41 Habitats of Principle Importance that are absent from NE data:

Differences in area of Section 41 Habitats of Principle Importance between Natural England (low resolution) and TVERC (high resolution) datasets:

We strongly recommend contacting TVERC for information on Section 41 Habitats of Principle Importance in Berkshire and Oxfordshire, by submitting a data request form, rather than using Single Habitats Layer from Natural England.                                                                   

Posted: November 22, 2019