effective precipitation Net precipitation after losses by evaporation. As higher temperatures increase evaporation, an index of effective precipitation derived from a temperature:precipitation ratio has been used as a criterion for some systems of climate classification (e.g. those of Köppen in 1936 and Thornthwaite in 1948).

effective precipitation Net precipitation after losses by evaporation. As higher temperatures increase evaporation, an index of effective precipitation derived from a temperature: precipitation ratio has been used as a criterion for some systems of climate classification (e.g. those of Köppen in 1936, Thornthwaite in 1948).