During his first flight of the day, the pilot of the glider experienced windy conditions and sinking air in the vicinity of the airport. He subsequently departed on a solo flight, flew for about 15 minutes, and then entered the airport traffic pattern for landing. To compensate for wind, he conducted the downwind leg of the traffic pattern at a higher speed, and entered the base leg early. On final approach for landing, the glider experienced a loss of lift and "rapid" loss of altitude, and landed short of the runway in an uneven area of vegetation, resulting in substantial damage to the forward fuselage. The pilot reported no mechanical malfunctions or anomalies that would have precluded normal operation.