To demonstrate how terrain models can inform runoff modelling, let’s take a look at importing a DTM from Nearmap into ArcGIS Pro for use with Spatial Analyst and the hydrology toolset.
Terrain models can be exported from MapBrowser by anyone with a Nearmap 3D Export subscription. The exported file contains a raster dataset where each pixel represents a bare earth elevation. Bare earth elevations are modelled to remove any above ground objects including buildings, cars, and trees.
When exporting from MapBrowser, you can select an option for pixel size (30cm, 60cm, 90cm). These options are based on a 15cm source resolution, and as the pixel size increases, you get an averaging of elevations and therefore a relative smoothing of the surface.