Estimating Evapotranspiration from Solar Radiation

TLDR

The study compiles water‑shortage data for municipal, industrial, and irrigation uses to develop practical planning guidelines for government agencies and consulting firms. Feasibility of irrigation is assessed via project‑specific economic analyses that factor in yield losses from shortages, with recommended limits of 3 % annual average, 3 % single year, 50 % over two years, 70 % over 50 years, and 27 % maximum shortage years. The authors conclude that any water shortage is unacceptable for municipal and industrial supply studies, while no definitive irrigation guidelines based solely on shortages can be recommended.

Abstract

An analysis of water shortages for municipal and industrial, and (project type) irrigation uses is presented. The investigation was undertaken to compile data on water shortages for these uses and to establish general practical guides for use in planning studies by governmental agencies and consulting firms. It is concluded that shortages of any magnitude should not be permitted in studies in which water is to be supplied for municipal and industrial purposes. In regard to irrigation, no firm guides and limitations based entirely on water shortages are recommended. In determining the feasibility of irrigation, economic analyses will be made, on a project by project basis, that will consider reduced crop yields due to water shortages. Desirable limits on water shortages for irrigation in planning work are considered to be as follows: Maximum average annual for 50-yr period, 3% maximum for a single year, 50% maximum for two consecutive years (total), 70% and maximum shortage years, 27%.