STANDARD PROBABILITY DENSITY FUNCTIONS OF CHARACTERIZING WATER QUALITY VARIABLES IN DIMICTIC GLACIALlBOREAL LAKES

摘要

With the secure supply of healthy fresh water being a threatened essentiality for the global society, compatibility among scientists working with water quality issues must be considered as highly prioritized. TO achieve this, a standard that facilitates compatible comparisons between statistical models that describe and/or predict lake water quality should contribute. A large population of dimictic glacial/boreal lakes -- with variable ranges wide enough to represent a majority of such lakes -- is therefore analyzed with respect to probability density functions of the seven characterizing water quality variables pH, alkalinity, conductivity, hardness, color, Secchi depth, and total phospho- rus concentration. With the lakes being limestone treated, the primary variables are transformed to normal distribution in cases' l; 'Before limestone treatment', 2; 'After limestone treatment', and 3; 'The entire database' (case l + case 2). It is concluded that the transformation functions derived in case 3 are sufficiently valid as optimal transformation functions in all three cases. This suggests that the transformation functions derived approximate the probability density functions of these important water quality variables in the generic class of dimictic glacial/boreal lakes, and that they should be well suited as transformation standards in natural, as well as in limestone treated lakes. It also implies that limestone treatment does not significantly alter the shape of the probability density functions analyzed.