Derivatives of digital elevation models are ideal for identifying flood-prone areas. For instance, the height above nearest drainage (HAND) derivative shows the height difference between a specific location to the nearest drainage (rivers, streams, stormwater canals). The featured image shows HAND for Franschhoek (as derived from GeoSmart’s DEMSA2 product) – one of the towns severely affected by the recent storms in the Western Cape of South Africa. HAND is one of the main predictor variables used in GeoSmart’s flood hazard index (FHI). Featured is a comparison between the two.