---- Kirsten Harma <[email protected]> wrote: > Does anyone know if someone has developed a single, integrated water quality index that combines the basic parameters (Temp, DO, Conductivity, pH and secchi depth). We're curious if there is an easy way to categorize a lake as in "good" "fair" or "poor" condition based on such an index (along the lines of an Index of Biotic >Integrity based on fish or macroinvertebrates).
I believe that would be a hard thing to make valid. Lakes can be very healthy with widely different values for most of those variables, depending on the lake. Geography, geology and so on make a difference. Mono Lake would be considered to be quite healthy despite its very high pH and conductivity, and low transparency. The same would be true of the Great Salt Lake. But Crater Lake would be considered very healthy also, despite its extreme transparency, and extremely low conductivity. There are simply different kinds of lakes. I believe a different index would be required for different regions and different underlying geological conditions. Development of indices of that nature might work out, though. And then we would just have to recognize exceptional conditions, conditions that simply don't fit. David McNeely
