Curbing Evaporative Loss of Stored Water

Abstract

Vast quantities of water — sometimes equivalent to a depth of about two metres — are lost by invisible evaporation from reservoirs, not to mention losses from open irrigation canals. The quantity of stored water which evaporates often exceeds that which is used productively. Small wonder than many ingenious attempts have been made to reduce this loss of scarce water. Some methods have yielded only small or questionable savings, others are more effective but too costly, while some are impractical to use on large water surfaces. It is unrealistic to hope for a single, universally applicable, efficacious method of evaporation control — the size and shape of reservoirs, and the climatic conditions to which they are subject, are too varied.