Comment:

A fundamental input is a Digital Elevation model (DEM). All algorithm calculations and valuations are produced at the resolution of this DEM – this ensures each service valuation delineates the landscape into elements consistent (identical) with the other service valuations so trade-offs can be meaningfully calculated. Applications to date suggest that a 5 m by 5 m DEM provides more than sufficient resolution for making decisions at the field scale. The extent to which utility decreases as resolution degrades is still to be established, but applications using 10 m by 10 m and 20 m by 20 m DEMS have to date provided generally appropriate information. A pre-processing tool is included with Polyscape to generate a hydrologically consistent DEM from a “standard” DEM.