How do I identify specific channel slopes and flood plain dimensions?


I am attempting to model a specific river in another software and need both the channel slope and the flood plain dimensions. Is there a way of accurately finding the data easily?

1 answer

Staff March 15, 2018

I recommend you take a look at the OS Terrain 5 and OS Terrain 50 products as these are detailed surface models.  Both these products are available in the form of vector contours and raster Digital Terrain Models (DTMs).  OS Terrain 5 is more detailed than OS Terrain 50, so if your study areas are small then I’d recommend using OS Terrain 5; and OS Terrain 50 for larger study areas.  Calculating slope angles is relatively straight forward in GIS applications – I suggest you search online for a tutorial suitable for the software package you are using.
There is no floodplain data in Digimap but you could use the datasets mentioned above to help identify areas prone to flooding. The Environment Agency ‘Flood Map for Planning’ dataset is available as Open Data and can be download from:


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