6.6.3. Zonal statistics
The Zonal statistics (Spatial Analyst) tool calculates the statistics on values of a raster within the zones of another dataset. For example, buffers could be used as input zones to calculate the statistics from any raster layer (DEM, slope, aspect, etc.) to determine the mean, majority, maximum, median, minimum, minority, range, standard deviation, sum, or variety of the raster pixels which are located within the buffer confines. The results are contained in a new raster layer and this should be conducted for each statistic required. To obtain multiple statistics at one time, the Zonal Statistics as Table (Spatial Analyst) tool can be used to generate the statistical results in table form for either all or selected statistic types. For an example of the use of the zonal tools, see the case study in section 6.9.7.