Dilution of Specific Electrical Conductance

A pattern that is emerging around New Hampshire is that specific electrical conductance is highest at low flows and becomes diluted as flows increase. This is because there are higher solute concentrations in soil water or groundwater and lower solute concentrations in rainwater. Higher solute concentrations in groundwater or soil water are partly natural, caused by dissolution of naturally occurring minerals. However, sometimes higher solute concentrations are elevated by human inputs of minerals, particularly sodium chloride as road salt. Natural or human-caused, this dilution pattern can tell us about how much groundwater contributes to a stream. But, I will leave this discussion to Ashley Hyde for another time. In the meantime, here is a picture of dilution from a downstream reach of the Israel River (or Israel's River). I am writing code to produce these pictures for each site, and this is the first picture I've been able to pull together. I was excited, so I thought I would share.