1. Filtering of elevation data 2. Locating pits 3. Calculating drainage accumulation/outlining watershed 4. Creating stream network 5. Coding stream segments/finding segment lengths 6. Finding subwatershed basins
The r.le programs are designed for analyzing landscapes composed of a mosaic of patches, but, more generally, these programs are capable of analyzing any two-dimensional raster or array whose entries are integer values. The r.le programs have options for controlling the shape, size, number, and distribution of sampling areas used to collect information about the landscape. Sampling area shapes can be square, or rectangular with any length/width ratio or can be circular with any radius. The size of sampling areas can be changed, so that the landscape can be analyzed at a variety of spatial scales simultaneously. Sampling areas may be distributed across the landscape in a random, systematic, or stratified-random manner, or as a moving window. The r.le programs can calculate a number of measures that produce single values as output (e.g. mean patch size in the sampling area), as well as measures that produce a distribution of values as output (e.g. frequency distribution of patch sizes in the sampling area) (Table 1), and it is also possible to output tables of data about selected attributes (e.g., size, shape, amount of perimeter) of individual patches, as well as to make new maps of patch attributes. The programs include no options for graphing or statistically analyzing the results of the analyses. External software must be used.