Classify Subbasin-Erosion

Step Wise Guide

Erosion

· Classify, by subbasins, erosion potential across a large watershed or landscape.

It may be useful to stratify a watershed or landscape according to erosion potential using a population of subbasins. NetMap digital watersheds come loaded with HUC 12 digit, 6^th field subbasins.

Step 1: Go to NetMap Basic Tools > Subbasin Classification> Sort/Rank. First, choose an erosion attribute to populate if you would like to save your work for later display (only available on a subset of attributes). Next, immediately below, use the drop down list to select an attribute (when choosing a field to populate, it the tool will automatically fill in the attribute). Then, select the type of classification you would like, e.g., using the mean, median or any percentile of the distribution.

An analyst could apply this type of classification across multiple NetMap digital watersheds (digital watersheds are approximately 500,000 acres on average or about 2,000 km²); this would require that the user apply the same numeric legend categories so that the color ramps are consistent across the datasets. In addition, custom subbasins may be imported and used (you will be prompted for the polygon file name).