The hot air balloon pilot reported that he performed a safety briefing with all eight passengers before they boarded the balloon. During the flight the winds, which were forecasted to be about 3 knots at the time of landing, increased to 14 kts, gusting to 19 kts. The pilot determined that the planned landing area did not provide sufficient room for a safe landing due to the increase in wind speed and elected to divert to a more open area. The balloon crossed over a valley and encountered a downdraft, which the pilot said he unsuccessfully attempted to overcome using the gas burners. He activated the rapid-deflation system to help prevent dragging; the balloon touched down hard and was dragged by the wind as it deflated. The balloon landed hard at about 23 kts, which resulted in a serious injury to one of the passengers. The pilot reported that there were no preaccident mechanical malfunctions with the balloon that would have precluded normal operations.