the GiGLer

The newsletter of Greenspace Information of Greater London CIC

Data fields of glory

Having recently completed the first phase of GiGL’s open space data project, Tim Hogg, GiGL’s Open Space Data Officer, reports on achievements so far, and gives an overview of some of the contents of the new open space dataset.

In Issue 3 of the GiGLer, John O’Neil, Senior Planner at the Greater London Authority and Mandy Rudd, GiGL Director, wrote about the possibility of creating a regional open space dataset to help London boroughs with evidence-based decision making, vis-à-vis open space provision around Greater London. In June this year, GiGL completed the first stage of ‘Mapping London’s Open Space’, an open space data project funded by the GLA, which created two GIS mapping layers; one showing all open spaces in Greater London and the other showing public open space deficiencies.

It is early days and both the geographical and underlying attribute data are an admixture of datasets from different sources; chiefly GiGL’s existing data holdings and data from about half of London’s boroughs and the GLA. All of this source material comes to us in different formats, reflecting the different priorities of the data owners. Planning and parks departments within the same borough, for example, held different types of data unique to their needs.

This first pan-London open space dataset is by no means complete or 100% accurate. Apart from the fact that not all London boroughs could contribute to the project, the quality and quantity of data varied greatly from borough to borough and, in most cases, needed interpretation and further manipulation. Even when GIS polygons are drawn accurately, a lack of underlying data undermines their integrity and usefulness. But, you have to start somewhere.

A standardised master dataset was created using eight key fields:

  1. Site reference
  2. Site name
  3. Area
  4. Borough
  5. Protection designation
  6. Co-ordinates
  7. PPG17 typology
  8. The London Plan’s “Public open space hierarchy”

Two of the key pieces of information used, PPG17 typology and the public open space hierarchy, became cornerstones of the first phase of the project. Both provide data essential for understanding the existing supply of open space and areas of deficiency.

PPG17 (planning policy guidance for sport and recreation) gives local authorities a “framework for assessing their needs for open spaces, making good deficiencies and protecting what is valued, and ensuring that everyone has adequate access to open space”. It also aims to “ensure that existing spaces are protected from development where appropriate and that new open spaces are well designed”. PPG17 typology gives boroughs a descriptive list to use when auditing existing open space and recreational facilities.

Most sites are multi-functional; they may contain a formal garden alongside a children’s play area and some sport fields.To avoid inconsistencies, we decided a primary purpose for any such site and added a sub-PPG17 column to give details of any other uses. The London Plan’s public open space hierarchy “categorises spaces according to their size and sets out a desirable distance which Londoners should travel in order to access each size of open space”. It is meant to help local authorities bolster the statutory requirements of their Local Development Frameworks through the Development Plan Documents contained therein. DPD’s should ‘identify broad areas of public open space deficiency and priorities for addressing them on the basis of audits carried out … using the open space hierarchy as a starting point’.

Categories within the public open space hierarchy include, in descending order of size, regional, metropolitan, district, local, small local, pocket and linear parks and open spaces. A district park can be a site from 2 to 20 hectares in size.There should be a district park no more than 1.2 kilometres away from your doorstep.A pocket park, on the other hand, is under 0.4 hectares in size and should no more than 400 metres from your home.A larger site satisfies the criteria of all categories smaller than it. So, if a regional park is within 400 metres of your house, it fulfils the criteria of all categories below it, all the way down to a pocket park.

We at GiGL hope to bolster our open space data holdings. An advisory group will be set up to further the development of open space data in the products and services we provide.

We will be in contact with those boroughs that provided data in the first instance and will return the standardised version of their data to them for verification and any other constructive comments.Those boroughs that sent data that wasn’t used in the first output will have their data returned to them in the standardised format but with ‘null values’ where information held by other boroughs is lacking in their own dataset.We will continue to encourage participation from the rest of the boroughs that did not provide data in the first round. Some copyright issues need to be resolved so that the data provided only for the first stage of the project can be used in future updates of the master dataset.The whole regional dataset will also need to be further refined as suggestions for alterations and additions arrive from the boroughs.

We are very excited about the prospect of building this new dataset in support of our partners and other GiGL users. For the first time, GiGL is able to show what we have known in theory but not previously been able to demonstrate visually. Mapping open space allows our users to immediately see areas of deficiency and to target resources accordingly.

Leave a Comment