Feb. 4/14-As the Hawkair DHC-8 (C-FIDL) descended through about 11,000 feet on approach to Terrace it encountered severe turbulance for 1 to 2 minutes. The autopilot disengaged, loose items went flying inside the cockpit, and the cabin flight attendant hit the ceiling and fell back to the floor. The seat belt sign had been turned on prior to the incident due to light turbulance and no passengers were injured during the event. The aircraft landed without further incident and the flight attendant was treated for minor injuries. There were clear skies, a strong north-easterly wind, and localized severe mechanical turbulence forecast.