Water loss

"1. In a water balance: sum of water lost from a given land area at any specific time by transpiration, evaporation and interception. 2. In irrigation: the losses made up of seepage and evaporation from canals and ditches, water lost from the canal system, excess water drained from land surfaces, and water lost from the soil by deep percolation below the root zone." (United Nations Publications, 2013)