Selecting parameters

The following parameter values can be specified that reflect risk management decisions that affect the criterion value.

• Target MC concentration - The microcystin concentration on which the criteria is based.

• Allowable exceedance probability - The probability with which the target MC concentration will be exceeded when chlorophyll concentration in the lake is equal to the specified criterion value.

• Certainty level - Because of model uncertainty, a range of criterion values are possible for a given combination of exceedance probability and target MC concentration. The certainty level specifies the range (gray area) within which the criterion value is located with the specified probability. The level is quantified as the credible interval, a measure of model uncertainty that is similar to a confidence interval. For example, if a certainty level of 75% is selected, there is a 75% chance that the criterion is within the bounded region. To ensure that the estimated criterion is protective, the criterion magnitude is computed as the intersection of the upper bound of the gray area and the targeted threshold (shown as red line segments).

• Lake maximum depth - Maximum depth of the lake of interest.

• Level III Ecoregion - Ecoregion of the lake of interest.

Note: All sliders have been set to the middle of their range, but these initial settings should not be interpreted as recommended values.