The triangle map (created through the Map -> Multivariate Maps -> Spider Map menu in the RockWorks Utilities and imported into ArcMap as a DXF) illustrates the relative percentages of Filtered Residue, Fluoride and Sodium in well water as triangles with variable shapes and sizes. Each triangle “axis” is scaled independently based on the minimum and maximum measured value of that constituent normalized to values ranging from 0 to 100.
The triangle map shows a general increase in constituents in well water in the in the southern portion of the watershed, as illustrated by larger triangles in Northumberland and Lancaster Counties. A more subtle trend can be seen when comparing triangles located along the groundwater divide (which generally follows the eastern border of Richmond County) to those closer to the rivers. There appears to be a correlation between proximity to a river and the amount of TDS, Sodium and Fluoride in well water.