PREPARING SPATIAL DATA
Spatial datasets (or layers) include site and administrative boundaries, as well as various types of environmental data, such as soils and habitats. On the NBN Atlas, spatial datasets can be displayed by all users in the interactive map and the spatial portal. They can be used as a backdrop to maps and they support spatial searching by specific area. As tools available via the spatial portal develop the spatial layers will also be used for more complex analysis such as species distribution modelling.
Required file format, naming conventions and data sources
When preparing a spatial dataset for the NBN Atlas you should consider the following:
- Site boundaries and environmental features must have been digitised as polygons
- The preferred format is an ESRI shapefile
- In the shapefile’s properties the Projection (or CRS) should be WGS84 and Encoding set to UTF-8
- Multi-part polygons are supported. If a site is defined by more than one polygon, these polygons should be grouped into a single multi-part polygon
- File name format: no spaces allowed (use an underscore), and all lower case letters
- The digitised dataset must either have been released under an Open Government Licence or have been created from Open Data sources
In the attribute table:
- Include a unique ID field
For example, for habitats this will usually be the habitat code; for areas or sites it could be a unique site code.
- Include a name field
This will be used to describe the feature classes in the legend and in search listings. For example, for habitats the name could be the habitat code or the habitat name. For areas or sites this will usually be the area or site name.
Note about spatial datasets created with reference to Ordnance Survey data
When creating a spatial dataset to be shared on the NBN Atlas please be aware that if any part of a feature has been created with reference to Ordnance Survey (OS) data as a source for its alignment, it can only be shared on a Google interface, like the NBN Atlas, if that source is an OS Open Data product and not a paid-for product such as Master Map Topography layer. The reason behind this decision by the OS is that Google’s terms and conditions are in conflict with those of the OS.
- spatial datasets created with reference to any paid for OS service, such as MasterMap Topography Layer, cannot be shared on the interface
- spatial datasets created using OS Open Data can be shared on the interface, and overlaid on Google Maps and Open Street Map bases
- for the avoidance of doubt this means that spatial datasets released under an Open Government Licence can be shared on the interface
If you are unsure of the status of your dataset or your dataset creation process please check with the Ordnance Survey. If your ability to send us spatial data is adversely affected by the above please do let us know. We are currently collating details of the impact this is having on data sharing.
METADATA REQUIREMENTS FOR SPATIAL DATASETS
Metadata is required for each spatial datasets. The information should be supplied in a spreadsheet and metadata for several different layers can be supplied in a single spreadsheet, although each layer requires a separate column. This information will be used to populate the layer’s metadata table in the NBN Atlas. Please provide details for each layer as per the items in the table below and as per the spatial dataset metadata spreadsheet template (updated June 2020).
The fields in the metadata spreadsheet are listed in the table below:
|Layer name||Please use the shapefile name||Layer name 1||Layer name 2|
|Layer title||Please provide the full name the dataset is commonly known by. It will appear in the spatial portal layer list|
|Publisher’s name||Please provide the name of the publisher’s organisation|
|Metadata source||This is usually a link to the layer’s metadata web page or a link to the publisher’s website|
|Reference date||This is the date of the layer’s publication|
|Licence type||Select from CC0, CC BY, CC BY-NC or OGL. If none of these options is appropriate please provide details and a link to the licence description|
|Layer copyright and attribution||Provide details of any copyright note(s) and attribution statements that accompany the use of the layer|
|Classification||Please define subject category; this will be used to classify the layer in the layer menu|
|Notes||You can use this field to provide extra information about the layer, if necessary|
|Frequency of update||Provide an idea of frequency of update (eg annually, quarterly; infrequently; never; not known)|
Format of dataset legend(s)
For complex spatial layers (ie all layers except site boundaries) it would help if you could show us how you would expect the dataset legend to look in the spatial portal. You could do this by sending a link to a site that already shows the data or a PDF or image of a map where the dataset is used.
Unfortunately the NBN Atlas spatial portal does not support the creation of nested legends, which means that polygons cannot be grouped in a hierarchy (as might be useful for habitat data).
Supplying spatial layers that are accessible via a website
If the layers you wish to supply to the NBN Atlas are available for public download via your website you just need to send us the url and a list of the layers to be downloaded. We will download the layers ourselves and upload them to the NBN Atlas database.
Please ensure that the layers adhere to the formatting instructions above and that sufficient metadata is available online to enable us to complete the NBN Atlas spatial dataset metadata form.
For further help with providing spatial datasets please contact us at email@example.com