GEOG209 Lecture Notes - Lecture 6: Vehicle Emissions Control, Evapotranspiration, Vapor Pressure
13 Jun 2016
School
Department
Course
Professor
Document Summary
Geog209 week 6 notes evaporation & transpiration. & evap. is the water available for direct human or plant/crop use. Most water lost via evap. is used to grow the plants that form the base of the earth"s land ecosystem. Much of worlds food supply is grown on irrigated land. Proper irrigation requires knowledge of crop water use (transpiration) Define: process by which a liquid (vaporization) or a solid (sublimation) enters the gas phase. Frequent dominant mode of annual water loss from natural systems. Driven by energy availability (radiation and energy balance) Controlled by: atmospheric vapour pressure deficit (vpd, aerodynamics (wind, surface (plant/soil) characteristics. Soil evaporation: water evap. from a wet surface. Potential evapotranspiration: max evap. rate when the moisture content of the soil and vegetation conditions is not limiting. Actual evapotranspiration: evap. rate under existing atmospheric, soil and vegetation conditions. Process where a liquid (vaporization) or a solid (sublimation) enters the gas phase.
