Puddles

A puddle is a small, shallow accumulation of liquid, typically water, that forms on a solid surface after rain, snowmelt, or other liquid input. Puddles are usually temporary and occur on ground, pavement, or vegetation where drainage or infiltration is limited.

Formation is influenced by surface characteristics. Impervious surfaces such as concrete or asphalt slow infiltration, while depressions in soil collect water. The size and depth depend on the amount of input, the ground's surface roughness, and drainage.

Physical properties include surface tension and capillary action. On flat surfaces, water forms a shallow disc with a curved surface. Evaporation occurs as temperature or wind rises, and freezing can turn a puddle into ice in cold weather.

Persistence and dynamics: puddles are often short-lived but may last longer in shaded, cool, or windy conditions. They may drain or infiltrate over time, or persist until evaporation, infiltration, or movement of the water.

Ecology: tiny ecosystems can develop in larger or longer-lived puddles, including algae, protozoa, and invertebrates. In warm climates, persistent puddles can serve as breeding sites for certain mosquitoes and other insects.

Human and environmental considerations: urban puddles can collect pollutants from runoff, such as oils, metals, and sediments. They may pose slip hazards and can influence local drainage patterns or flood risk during heavy rain.

Cultural notes: puddles are a common feature in childhood play and appear in art and literature as symbols of reflection, transience, or rain.