From warming stripes to warming patches

Some weeks ago, and following the work of @ClimateLabBook, I produced a ‘warming stripes’ graph, illustrating the rise of temperature in Scotland in recent years.


Each stripe corresponds to a year, from 1910 on the left hand to 2017, and depicts variations in temperature. Intuitively, blue stripes show values under the average and red lines illustrate years with temperatures over the average. More saturated colours represent higher (or lower) temperatures, while shades of white correspond to temperature values close to the average.

A more complete graph can be produced if monthly average values of temperature are considered (instead of yearly figures). Following the same colour code used for the previous plot, a ‘warming patches’ map is created, illustrating for each particular month (e.g. January 2017) its variation of temperature with respect to historical records for that month (other Januaries).

The first line corresponds to January and the last one to December. And columns go from 1910 (left) to 2017.


Extracting elevation values for buildings

In this post, a strategy to obtain the elevation of certain locations (i.e. buildings) is proposed.

First, a digital terrain model (DTM) is needed. In the example, the OS Terrain 50 has been used. This is a 50m gridded DTM, with 10m contours and spot heights, which is provided by the Ordnance Survey. In the next figure, the DTM for the Edinburgh area is shown.


Note that a ‘Merge‘ operation might be needed if the region of interest is covered by several DTMs.

After this operation, a Digital Elevation Model (DEM) is obtained after the DTM. This raster is created by means of the tool ‘Topo to Raster‘. In this example, an output cell size of 50m was used.


As illustrated in the DEM, the Arthur Seat, in Holyrood Park, is the highest area in Edinburgh. In the West part of the city, Hillwood Park is remarkable, as well as the Pentlands in the South.

Finally, elevations are extracted from the DEM for all the buildings/regions under study. In this case, the next figure shows the elevation of the properties managed by Historic Environment Scotland (HES) in Edinburgh, which have been extracted by means of ‘Extract multivalues to Points‘.