EVAPO-TRANSPIRATION

EVAPO-TRANSPIRATION

It includes evaporation of liquid water from river, lakes, soil and vegetative surfaces as well as transpiration by plants and sublimation from ice and snow surface.ion

When sufficient moisture is freely available to completely meet needs of vegetation fully covers in an area resulting evapo-transpiration is called Potential Evapo-transpiration (P.E.T). The real PET occurring in a specific situation in the field is called Actual Evapo-transpiration (A.E.T). PET critically depends upon climatology factors rather than the characteristics of plants soil. But AET is largely affected by the characteristics of soil and transpiration from the vegetation in real environmental condition. PET includes the maximum quantity of water capable of being evaporated from the soil and transpiration from the vegetation of a specific surface.

FACTORS AFFECTING EVAPO-TRANSPIRATION

·         SOIL FACTOR

·         PLANT FACTOR

·         ATMOSPHERIC FACTOR

·         CULTURAL PRACTICES FACTOR

METHODS FOR ESTIMATING EVAPO-TRANSPIRATION

·         BLANEY CRIDDLE EQUATION

·         THRONTWAITE EQUATION

·         PENMAN’S EQUATION

EVAPO-TRANSPIRATION CAN BE REDUCED THROUGH THE FOLLOWING MEASURES

·         By reducing the surface area of water body instead we can increase the depth of water body which reduces evaporation.

·         By applying chemical over the water surface so that it forms a thin layer over the surface and reduced evaporation.

·         By destroying the unwanted plants that transpired efficiency.

·         By breeding new plant varieties that transpired less.

·         By using appropriate land use changes in the catchment which increase stream flow.

·         By mulching over the plant body.

·         By reducing air movement over a crop by wind brake of inter planted row of taller plants.