Neighbourhood Planning data loading proposal
This project intends to:
- Add data to OpenStreetMap describing the geographic extent of and various attributes about individual Neighbourhood Planning Areas (NPAs);
- Provide a baseline/foundation dataset for local communities and groups to add and improve information about their NPA;
- Stimulate new and innovative uses of a consistent, comparable dataset about NPAs – e.g. by enabling application developers and innovators to build new tools to query, explore, visualise and enhance NPA data at the local and national level.
As a starter for 10, I have uploaded a small (463 node) set of data, and developed a basic application (here http://dclgexamples.mywebcommunity.org/npf/npanodes_osm.html) to demonstrate querying and re-use via OSM's XAPI.
Background on neighbourhood planning and NP areas
Neighbourhood Planning is a right introduced by the Localism Act 2011. Communities can, for the first time, produce plans that have real statutory weight in the planning system within a specific area. Through neighbourhood plans, communities can choose where they want new homes, offices and shops to be built; have their say on what new buildings should look like and grant planning permission for the new buildings they want to see go ahead. More information can be found at https://www.gov.uk/neighbourhood-planning.
A town or parish council or a community group applies to their local planning authority for an area to become a neighbourhood area. At the time of writing, around 500 local areas have either applied for, or been officially designated by their Local Authority as a Neighbourhood Planning Area. A neighbourhood planning area can cover any neighbourhood, as long as it is coherent, consistent and appropriate; they will differ for different areas across the country, and should be what is most appropriate for that area. There will be a strong assumption that existing town or parish council boundaries will define the neighbourhood area, but this will not always be appropriate. Neighbourhood areas often comprise:
- Individual, whole Parish Councils – i.e. where the NPA boundary follows the designated Parish line.
- Individual, whole electoral wards - where the NPA is coterminous with designated ward boundary.
- Multiple parish councils – i.e. where two or more parishes are collaborating on a neighbourhood plan, and the boundary therefore follows the combined, designated parish areas.
- Multiple electoral wards – i.e. boundary is coterminous with designated boundaries.
- Partial parishes or wards
- Community-defined – e.g. following the boundary of a local neighbourhood, as defined by a resident group in their NPA application.
The NPA dataset
The dataset has been compiled manually through gathering information from relevant public websites and media sources. As such, it is not an official Government source, and it may not be 100% accurate or up to date. However, I think it is currently the most complete data set on neighbourhood planning, and I want to make the information openly and freely available to others to improve and re-use.
In broad terms, the proposed first steps are to:
- Agree source datasets for defining individual or combinations of parish or electoral ward boundaries.
- Agree standard OSM tags to define NP areas and associated attributes.
- Agree the method for re-using existing OSM data – i.e. parish or ward boundaries already defined in OSM.
- Agree the process and protocols for resolving discrepancies between existing and proposed parish or ward boundary data – e.g. where quality or positional accuracy of current OSM content differs from data in the proposed import.
I hope we can complete these first steps by end-April 2013. Data loading will then commence as outlined below.
Parish and electoral ward boundaries will be sourced from Ordnance Survey’s latest OpenData BoundaryLine product.
Additional NPA attributes (to be defined in tags) have been captured from individual local authority and NPA public websites, and there are no license or copyright limitations.
OSM Data Files
OSM files will be prepared once I have completed the first steps outlined above.
This import will be a once-only upload for all known NPAs as at end-April 2013. I anticipate that this will comprise:
- Ways forming the boundaries of areas derived from parishes or wards – approximately 400 areas in total, scattered throughout England.
- Individual nodes, marking the best fit centroid for areas where digital boundaries are not readily available – approximately 100 nodes in total, again scattered throughout England.
As set out above, it will then be up to the NPA community to maintain and improve it using their preferred OSM editing tools and applications, or for the wider neighbourhood planning community to use and update the information.
The import will be undertaken using JOSM.
Data will be prepared using Quantum GIS. Key steps are:
- Acquire latest shape files forming Ordnance Survey’s BoundaryLine Opendata product (to be downloaded from OS’s open data website).
- Use Quantum GIS to re-project these sources to the standard WGS-84 projection. Origin offsets will not be applied.
- Use Quantum GIS to extract from OS Boundary-Line the Parish and Ward polygons for NPAs.
- Use Quantum to merge and extract polygons for NPAs covering multiple parishes or wards
- Use Quantum to create points (best fit centroids) for NPAs that do not follow whole parish or ward boundary lines.
- Use Quantum GIS to capture and assign additional attributes about each area.
The results will be saved to a single shape file.
Data Reduction & Simplification
The primary task is to determine whether polygons in the shape file already have an equivalent good quality, complete boundary defined in OSM. If so, these will be re-used.
The assumption is that existing OSM data will be structured and organised according to best practice for publishing inter-related boundaries. We should find that current OSM parish or ward boundaries are:
- Correctly tagged as “boundary=administrative”, at the appropriate admin_level;
- Split into multiple ways, with outer relations used to define where/how each way is shared between two or more areas.
- Assigned an additional outer relation to define the area as a whole – i.e. relating the individual line segments (ways) to form the area polygon.
The first step will be to search OSM to determine whether these well formed boundaries already exist. This will be undertaken by working through the list of local authority districts which I know have received applications from, or designated NPAs.
For each district, I will:
- Use OSM’s XAPI to query the local authority’s bounding box for nodes, ways and relations containing the above tag patterns
- Use this tool (http://layers.openstreetmap.fr/?zoom=11&lat=51.00606&lon=-0.08008&layers=0B000FFFFFFFFFFFFTTFFFFFF) to visually inspect the district area for completeness and accuracy of existing areas. (thanks to user MaarsenMapper for this link).
For areas which already exist, and are of suitable quality, I will clone the outer relation for the whole area, and include tags describing the NPA – see tag list below.
For NPAs built from multiple parishes or wards, I will re-use ways forming the boundary of the combined area. A new outer relation will be established to describe the whole area, with tags describing the NPA – see tag list below.
For areas which do not exist in OSM, I will use JOSM to process the polygon from the source shape file, splitting it in to its component ways and assigning outer relations. Where appropriate, this will include re-using line segments from neighbouring areas – e.g. where parishes or wards sit share a boundary of with the parent local authority, which may already be present in OSM.
The import will create the following tags for each NPA
|boundary||A mandatory tag. Value will always be “planning”|
|designation||A mandatory tag, with the value always set to “neighbourhood_plan”.|
|name||Name of the NPA area|
|local_authority_name||Name of the Local Authority in which the NPA resides|
|local_authority_code||The 9 digit code (beginning with “E”) as defined by the Office for National Statistics|
|stage_reached||Stage of Neighbourhood Plan for the Area. Valid values are:
|date_area_applied||Date the area formally applied to the Local Authority for designation as an NPA. Formatted as DD/MM/YYYY|
|area_map_coverage||Area covered by the NPA. Can be:
|date_area_designated||Date the area was formally designated as an NPA by the relevant Local Authority. Formatted as DD/MM/YYYY.|
|legend||Valid values are:
|planning_document_type||Valid values are:
|qualifying_body_type||Can be either: Forum, Parish Council or Town Council|
|np_website||Full URL to the NPA website, where available|
|la_website||Full URL to the Local Authority Website, where available|
|area_map_original||Link to documents describing the area.|
Changesets will be tagged as “Neighbourhood Planning dataset – initial, one-off load”. I will also undertake loading via a new OSM user ID – npa_loader. Data Merge Workflow
I am undertaking the load on my own.
See sections above on dataset preparation, and data redaction and simplification.
There will be one changeset per local authority district. In the event of problems, changesets will be reverted using JOSM.
As noted above, data will be QA’d prior to importing – e.g. by checking for and re-using exiting OSM parish/ward ways.
I will use the OSM Relation Analyser (http://ra.osmsurround.org/index) to confirm that outer relations between ways forming area boundaries, and the whole area have been correctly applied.