What can increase the intensity of fire in valleys?

The intensity of fire in valleys can be significantly influenced by the concentration of wind. In valley areas, winds can funnel through and become concentrated, leading to increased fire spread and intensity. When winds are funneled along the valley floor or through narrow passages, their speed may increase, which can enhance the drying of vegetation and provide more oxygen to the fire. This combination often creates a more vigorous and fast-moving fire, as the wind drives the flames and assists in the combustion process.

Higher vegetation density can indeed fuel a fire but would not inherently increase its intensity due to environmental conditions such as wind. Accumulation of moisture tends to suppress fires and dampen their intensity, while a decrease in temperature generally does not support the rapid spread of fire. Thus, wind concentration stands out as a critical factor in escalating fire intensity in valley environments.