Water Cycle Terms Radiation is the suns energy (heating water). Evaporation is water (liquid) changing to water vapor (gas). Evaporation requires energy. Condensation is water vapor (gas) changing to water (liquid). Condensation releases energy. Precipitation is any form of water falling from the sky. Infiltration/Percolation is water filtering into the ground. Runoff is water that flows on top of the ground. Perspiration is water that comes out of animals in the form of sweat. Respiration is from breathing. Transpiration is water that comes out of plants.
Infiltration Infiltration is water moving into the ground. Most precipitation that reaches the surface i ii infiltrates the ground. Infiltration can only occur it the surface is p pp permeable (allows water to flow through), and is unsaturated.
Permeability regolithMost infiltration occurs in the thin layer of rock, sand, gravel and soil lying on top of the bedrock. This layer is called the regolith. PermeabilityPermeability refers to the ability of the regolith to allow water to pass through. impermeableMaterial that does not allow water to flow through is said to be impermeable.
Water Table When water can not infiltrate deeper and fills the pores above the impermeable layer a z zz zone of saturation forms. The upper surface of this zone is called the w ww water table. The zone above the water table is called the z zz zone of aeration.
Porosity PorosityPorosity refers to the amount of open space between the pores of a material. Porosity Particle sizePorosity of a loose material is dependent on the shape, packing, and sorting of the material. Particle size is not a factor. PorosityPorosity is usually expressed as a percentage comparing the volume of open space to the total volume of the material.
Capillarity CapillarityCapillarity is the ability of water to move upward through small openings in soil. –The smaller the particle size the greater the capillarity.
Surface Water Runoff runoffRunoff is water that does not infiltrate the ground. There are many factors that affect runoff. RunoffRunoff occurs when: –Rain fall exceeds the permeability rate –Slope of surface is too steep to allow infiltration.