Metrics

The FFC calculates metrics describing ecologically relevant components of the annual streamflow hydrograph. The metrics are organized into four seasonally-based functional flow components, in addition to two summary metrics (average annual flow and coefficient of variation) calculated for each water year. The FFC metrics are listed below.

Annual

• Average annual flow

• Coefficient of variation

Fall Pulse Flow

• Pulse magnitude

• Pulse timing

• Pulse duration

Wet Season

• Magnitude

• Timing

• Duration

Peak Magnitude Flows

Each of the following metrics is calculated annually for individual high flows that exceed 10-year, 5-year, and 2-year recurrence intervals of annual peak flows across the period of record:

• Magnitude

• Duration

• Frequency

Spring Recession Flows

• Magnitude

• Timing

• Duration

• Rate of change

Dry Season Baseflow

• Magnitude

• Timing

• Duration from start of dry season low flows until the start of the wet season of the next water year