After hearing about the devastating impact of cyclone Idai in Mozambique, Malawi and Zimbabwe, we thought it might be helpful to compile a map repository where maps and satellite data are from all different sources are combined.

We have combined topographic maps, elevation data, rivers, houses and many more in 1 online platform for easy viewing on both desktop and smartphones. The maps can be viewed here:
https://samsamwater.com/idai

If you navigate to the “Layers” tab you can toggle all the different layers.
There’s a range of maps from different sources. I’ve highlighted a few map types and possible uses below.

Topography
A detailed topographic map (left) compared to OpenStreetMap (right). The topographic map shows much more details including (unpaved) roads, swamps and small streams. The topographic map is old (made by the Soviet military in the 1980’s) so don’t rely on it for settlements, but landscape features (like wetlands) and roads are often still very accurate.


Hydrology
An easy overview of all watersheds (catchments), rivers and tributaries in the region and (in dark blue) the extent of the flooding:


Elevation
Left: Elevation map (only for elevations from 0 to 50 m above sea level for increased contrast)
Mid: Elevation map + flood extent map (derived from satellite imagery by ESA)
Right: Elevation + flood extent + buildings (mostly houses, derived from OpenStreetMap)

I’ve also added an elevation map in the platform for the full area (from 0 to 2500 m+MSL) which might come in handy for areas more upstream. And you can change the transparency of the individual layers using the sliders.

If you zoom in you can see that, luckily, most houses are constructed on the higher grounds, but maps like these could be used to identify priority areas such as where people might be trapped:


If you are working on something where maps like these could be helpful, please let me know and I can think along with you and see what data is available and how we can visualise that in the best manner.