How many times do we see a map then up pops another using a very similar technique soon after. Only a couple of weeks since we saw Block by Block, Brooklyn's Past and Present which mapped building age in Brooklyn and now we have The Netherlands mapped in a similar way.
I wrote a blog called Taste the Rainbow which explored the problems of mapping sequenced data using a qualitative colour scheme and so this is a follow up, second helpings if you will, that comments on the colour on this new map. The Brooklyn map used a full spectral colour scheme and the point I made in the previous blog was simply that there was no way you could see any date sequence in the map with that colour scheme.
Made by Bert Spaan, the map of The Netherlands makes pleasant viewing with highly saturated colours on a dark background. Only the buildings are shown so the structure of the city gives the map its structure. No other data is necessary. It resamples a little as you zoom out but quite honestly at smaller scales the map doesn't have much impact. There needs to be some aggregation of the data and new symbolisation applied. At larger scales the individual buildings can be seen (and queried).
The use of colour on this map is certainly an improvement on the Brooklyn map. It uses a dichromatic colour scheme so we can see (a) buildings that share similar construction dates and (b) how neighbouring buildings are dated in relative terms. Dark reds move into oranges into yellows. But there are still problems. The colour scheme then goes into light blues and then onto dark blues. Why use dichromatic? There's no obvious reason why red should be old and blue should be new. Why not just use a single hue in a sequential scheme, light to dark? Then we could genuinely see at a glance older to newer.
Don't get me wrong...this map makes huge strides over the Brooklyn one and corrects the basic errors made. It just seems to still want to use lots of colour when actually, a brevity of colour and a more judicious use of lightness and saturation would give a map that communicates the key information more easily.
Is this an example of the map-maker wanting to use a full palette because it grabs attention more? Possibly. Throwing colour on a map is easy. It doesn't always do the data or purpose justice though.