Which of the following factors can influence fire spread in wildland fires?

Wind speed is a critical factor influencing the spread of wildland fires. Higher wind speeds can significantly accelerate the rate at which a fire spreads by pushing flames and embers ahead of the fire front. This can create spot fires, where the fire ignites new areas ahead of the main blaze, further complicating containment efforts. Wind also affects how a fire might shift direction, making unpredictable movements that can pose additional risks to both firefighters and surrounding communities.

The other factors mentioned, while important in different contexts, are not directly related to the spread of wildland fires. Aging building materials typically pertain to structural fires and their associated risks. Water supply is crucial for firefighting efforts but does not influence how quickly a fire spreads in the wildland environment. Occupancy type relates more to how buildings might interact with or resist fire, especially in urban settings, rather than the dynamics of fire behavior in the wild landscape.