Site selection
Using geography to help make better informed decisions
In this example we are looking at an organisation that is looking to site a new facility, it could be retail, office space, distribution, entertainment, or any other function. For any of these however there is a level of investigation that can be done using geography to help identify a suitable site.
To start with we can look at where the organisation has sites currently across the region.
However where sites are located and how they are connected are not the same thing, so here we have now got the drive time buffers for 30, 60 and 90 minutes from each of the sites. This reveals that along the motorway and primary A road network the current sites cover a large part of the region with a noticeable gap along the south and southwest coast.
If we then look at some of the constraints on a new site we can look at National Parks, Areas of Outstanding Natural Beauty, Sites of Special Scientific Interest and Nature Reserves which is data that comes from Natural England. Looking in the southern region this pretty much ties any new site down to the major cities of Southampton, Bournemouth and Portsmouth due to the constraints of the 2 National Parks in the area.
We can then take a look at some of the more human aspects using ~Office of National Statistics data for population density. In this case, where are the people that we might want to come to a completed retail or entertainment site, or the people to work at the site regardless of the function.
Then we need to look at connectivity. First we can look at connectivity by air and here we have the major airports across the region with 45 minutes drive times around them. Airports at Southampton and Bournemouth cover the region well between them.
Next we can look at road and rail connections. There is a strong motorway connection into the area and arterial primary A roads running east and west across the south coast and up to Salisbury as well and mainline rail connections to London, Bristol, Oxford and across the south coast.
Looking at the transport options we are going to continue the scenario using Southampton as a potential site for the following reasons:
It has an airport, the connections by road or rail to London are shorter, it does not involve crossing the New Forest to reach (a major tourist destination and cause of traffic) and it sits at the centre of the south coast urban areas
Looking at a revised drive time map, we can see that the southern region is now nearly completely covered from this location
If we compare that to the population density map from earlier we can see that a large majority of the major population centres across the south coast are incorporated within the 60 minute drive time buffer. If we shifted it east to Portsmouth, Bournemouth and Salisbury would be missed out and if we shifted west to Bournemouth, Portsmouth, Chichester and Bognor Regis would be excluded.
So having established that the potential city has good connectivity, what is the demographic of the area like? In this case we are using Income Deprivation form ONS as a measure of the make up of the region, although there are other datasets from the likes of CACI or Experian which show demographics.
The data shows that, apart from the cities, the area within the 60 minutes drive time buffer is mostly in the Least Deprived 50% of the statistical range. For retail or entertainment that could imply customers with potential to spend if visiting the new site.
Next, let's take a look in more detail at potential sites around the City of Southampton. Six sites are picked out on the map shown here. Each has pros and cons depending on your requirements.
The three around the outskirts all have excellent road access being so close to the motorway network and motorway junctions.
The airport site and the three in the city centre all have access to the rail network whereas Adanac Park and Bursledon do not.
Two of the sites in the city centre are brownfield sites as they are both 'Former...' sites.
Depending on the function of the site these, and other criteria, will have different weighting. If it is distribution, the the sites on the motorway and by the airport are ideal. If it is retail or entertainment then being in the city centre closer to other similar facilities that would attract potential customers would be more useful.
Looking at the three central sites, we can see a bit more detail. Leisure World and West Quay are close to the primary A road, Leisure World and Debenhams are brownfield sites, and Debenhams is further away from the train station than the two.
We can also see that the Leisure World site is the largest whereas the West Quay and Debenhams sites are more constrained by existing infrastructure around them.
Looking at the 'land use' of the buildings (using OS NGD Buildings data) in the centre we can see a concentration of retail for which all three sites could be added to easily. West Quay and Leisure World both could be hotel sites and be part of a wider quarter of hotels in the city. Leisure World could also become Industrial and fit with the surrounding building use.
Looking at building heights from OS NGD Building Part we can see the distribution of tall buildings, so any planning could then be sympathetic with the area.
Sometimes it is also useful to know what a site was used for in the past and accessing historical data can help answer this. In this map from the 1930s the Leisure World site is part of the wider reclaimed docks, the West Quay site is part of the Pirelli works and the Debenhams site is a different building.
In this map from the 1960s the Debenhams site has become as it is now, whereas the other two are part of an expanded Pirelli manufacturing site.
In this case there is nothing controversial revealed on the historic mapping for any of these sites. But that is not always the case as these could reveal quarries, land fill sites of coal mines.
Finally there is the issue of flood risk. Risk of Flooding from Rivers and Sea (RoFRS) from the Environment Agency shows that the Debenhams site is at risk of flooding and both the West Quay and Leisure World sites are on the edge of areas at risk.
So we can see that geographic data can play a part at every stage of a site selection process, from where in a region to focus on, where in a city to focus on and which specific site might be best suit the needs of the organisation that is looking to site a new facility.
Further detail about these can be found on the OS website product pages
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More story map examples like this one can be found on the More Than Maps site.
