Air expands and thus cools. Plot data for a station. Evaporation Evaporation is the term for vaporization of water from free water surfaces or from bare soil. The combined process of transpiration and evaporation. Transpiration is defined as the loss of water from plants in the form of vapor.
Transpiration is dependant on plant type, density of vegetation, growth stage.
A hyetograph plots rate of rainfall versus time. These are often plotted with hydrographs for single events. C is based on land use type and read from a table. Now a lot of this work is done by models aided by GIS maps in which land uses can be more accurately portrayed.