Isoplaths

An isoplath map is a type of contour line map that uses lines to connect areas of equal acidity's. These contour lines are known as isoplaths, hence the term "isoplath map." An example of an isoplath map is shown below:

http://www.globalchange.umich.edu/globalchange1/current/lectures/kling/water_nitro/USAacid_rain2.gif