Visualising New Zealand SDI using LINQ

Our work on What’s My Spatial.IQ? led us to the notion of tracing the information flows that culminate in the map – think of this in terms of the spatial information supply chains that create these web maps.  These information flows are interesting.  They define Spatial Data Infrastructure (SDI) in a way that emphasises the business outcome as expressed in the value of the map.


We’ve captured New Zealand SDI using our methodology and tools for capturing these information supply chains; LINQ.  We’ll be talking more about LINQ in forthcoming blog articles, suffice to say for now that in the context of these SDI diagrams, the language we use is in terms of ‘actions’ (orange nodes) and ‘information’ (green nodes):  “information is used by an action to create information”.

These diagrams are interactive:  you can click on nodes to access the resource referenced by the URL:  the organisational website, the map or the information service.

In tracing these information flows, we are tracing what we can see in the public domain.  We can’t see services which are hidden behind firewalls (which might represent government to government services for example) and we can’t see those information services which have been proxied away so that only the map can consume them.   Where it is clear that data is provided by a specific agency, we have hypothesised the supply connection:  in the case of New Zealand, we know that parcel data is supplied by LINZ as files and these are used by other entities.

LINQ objectively measures the current state; warts and all.  We make no statement about technology, standards or any other aspect of this current state.  We believe that by measuring this current state, we create a baseline from which improvements can be more objectively planned and implemented.

Just because the information services are exposed and in the public domain, does not mean that you should just connect to them and use them in your application.   Each service will likely have terms and conditions associated with them – ideally contained within the service metadata.  The absence of metadata (sadly, all too frequent) should not be taken as permission to use.  You must contact the service owner (again, sadly rarely contained in service metadata) to obtain their permission and service level agreement.

Above all, if you spot an error or know about an update, please let us know and we will sort it out quickly.