I am in an early stage of least cost paths analysis of a wide area. One part of the operation includes simulation of movement across the grid of previously agreed size of cells and extent of the grid (for reference one cell is 5X5 km).
I have easily enough created the grid (as vector - polygon file), however i would now need to provide friction values as a attribute input for each cell (each cell is a separate polygon entry), based on the above the sea level values from an underlying DEM model (SRTM in this case). In short this would, ideally, look like this: - if a 5X5km cell contains more than 50% of surface that is of certain above-the-sea level, i would attribute a value to it from a devised chart of values that describe the friction value for this cell.
Can someone suggest how to proceed with this?
I am quite uncertain how to satisfy the "above 50%" condition. While i expect to be working with raster data, majority of work will be done while working in table format, with values extracted from various cost raster.