In addition to seasonal and statistical results, HEC-EFM also computes relationship-based ecovalues and dates of occurrence for each season within the period of record, as well as indices that involve multiple relationships. Ecovalues are useful in assessing how successfully habitat is provided. Dates of occurrence are useful in assessing the seasonality of habitat availability. Indices are used to numerically combine several relationships to compute a single measure of how a flow regime more broadly affects an ecosystem or ecosystem component.