The Diamond Geezer is, this month, climbing the highest tops in each one of London’s 33 boroughs.
To find the highest points, he’s used a number of websites which list the places. These derive the data from contour lines, perhaps supplemented with GPS or other measurements. However, another interesting – and new – datasource for calculating this kind of metric, is OS Terrain 50. Released as part of the Ordnance Survey Open Data packages, it is a gridded DEM (Digital Elevation Model). It’s right up to date, at 50m x 50m horizontal resolution, and 10cm vertical resolution, and it should correct for buildings, so showing the true ground height.
Looking at the DEM for Newham, I think it reveals a new highest point – not Wanstead Flats at 15m above sea level, as Diamond Geezer’s lists suggest, but Westfield Avenue, the new road that runs through the Olympic Park. Beside John Lewis, the road rises, to a highest point of 21.6m. It shows as purple in the graphic above. Nearby, the new “bowl” of the lower part of the Olympic Stadium can be seen, as well as the trench through which High Speed 1 runs, at Stratford International Station.
I can’t argue with the Chancery Lane/Holborn junction as being the highest ground-point in the City of London, at 21.9m. In Tower Hamlets, it’s more tricky. The old railyards between Shoreditch High Street and the lines into Liverpool Street look like they are at 21.7m, however the ground here is not publically accessible, and the DEM is quite noisy here, with only part of the railyard showing this height.
I’m looking for a way to do this programatically – calculating the highest DEM value for each borough. I’ve tried using QGIS’s Zonal Statistics plugin, with polygon shapefiles of London’s boroughs, but this only shows the mean value of the DEM for that borough.
Here’s the list I’ve created by measuring – the main issue with my dataset is that the measurements are only at the centre of each 50m x 50m cell.
|Borough||Hgt (m) 50m cn||10-digit grid ref||Description of
|Barking and Dagenham||45.3||TQ_48590_89948||Industrial area just E of northern part of Whalebone Lane North.|
|Barnet||146.1||TQ 21955 95622||Just south of the water tower to the east of Rowley Lane, near Rowley Green.|
|Bexley||81||TQ 45737 71256||Langdon Shaw, southwest side.||Yes|
|Brent||91.2||TQ 20732 88877||Junction of Wakemans Hill Avenue and The Grove.|
|Bromley||246.5||TQ 43637 56487||A233 – where Main Road changes name to Westerham Hill||Yes|
|Camden||135.6||TQ 26277 86225||Lower Terrace, just off Heath Street in Hampstead.||Yes|
|City of London||21.9||TQ 30970 81612||NW edge – junction of Holborn and Chancery Lane.|
|Croydon||175.7||TQ 34330 61827||Sanderstead Plantation, SW path crossroads.|
|Ealing||81.5||TQ 16177 84398||Horsenden Hill|
|Enfield||118.7||TQ 25632 97674||Just north of Camlet Way, Hadley Wood, opposite Calderwood Place.||Yes|
|Greenwich||131.1||TQ 43831 76583||Southern end of Eaglesfield Recreation Ground on Shooters Hill.|
|Hackney||39.8||TQ 32025 87574||In Finsbury Park, beside Green Lanes, opposite No. 330.||Yes|
|Hammersmith and Fulham||45.9||TQ 22960 82756||Harrow Road at north end of bridge over the railway line near Kensal Green station.||Yes|
|Haringey||129||TQ 28326 87479||Ground by Highgate School Chapel, just north of Highgate High Street.|
|Harrow||153.4||TQ 15288 93808||Magpie Hall Road, between The Common and Alpine Walk.||Yes|
|Havering||106||TQ 51192 93055||Churchyard of St John the Evangelist church (also Broxhill Road by the cricket pitch)|
|Hillingdon||130.5||TQ 10585 91678||Junction of South View Road and Potter Street Hill||Yes|
|Hounslow||33.6||TQ 11320 78815||Western Road – bridge over the Grand Union Canal.|
|Islington||99.9||TQ 28874 87217||Highgate Hill and Hornsey Lane junction.||Yes|
|Kensington and Chelsea||45.7||TQ 23014 82728||Kensal Green Cemetery, northern edge, beside the Harrow Road, above the railway line.||Yes|
|Kingston upon Thames||91.3||TQ 16644 60376||Telegraph Hill|
|Lambeth||110.9||TQ 33620 70729||Westow HIll and Japser Road junction.||Yes|
|Lewisham||111.2||TQ 33918 71779||Sydenham Hill and Rock Hill junction.||Yes|
|Merton||56||TQ 23627 70823||Lauriston Road and Wilberforce Way NW junction.|
|Newham||21.6||TQ 37967 84530||Westfield Avenue, outside John Lewis in Westfield Stratford City.|
|Redbridge||91.5||TQ 47945 93784||Cabin Hill|
|Richmond upon Thames||56||TQ 18779 73065||Bridleway/path junction just east of Queens Road, opposite the Pembroke Lodge car-park and to the NE of it.|
|Southwark||111.5||TQ 33926 71686||Sydenham Hill, between Chestnut Place and Bluebell Close.||Yes|
|Sutton||146.4||TQ 28383 59986||Middle of rectangle of land south-east of Corrigan Avenue and south-west of Richland Avenue.|
|Tower Hamlets||21.7||TQ 33720 82184||Railway yards between Shoreditch High Street station and the railways lines leading to Liverpool St Station.|
|Waltham Forest||92.2||TQ 38415 95010||Pole Hill (north top)|
|Wandsworth||60.7||TQ 22881 72780||Big Alp, Wimbledon Common|
|Westminster||53||TQ 26627 18386||Finchley Road and Boundary Road junction.||Yes|