| To better understand the values of water within different contexts and spatial scales, the emergy inputs to water were evaluated and compared at four scales: (1) global, (2) regional (the state of Florida), (3) local (water supply utilities), and (4) small-scale (home water purification). Emergy (spelled with an “m”) represents all the previous work of one kind required to generate a product or provide a service.; Since water can be found at all stages of the global hierarchy of biogeochemical processes, it has many emergy values and transformities. Transformities of water indicate the convergence of energy and materials that are required to produce the water. Global water storages were evaluated using the total emergy driving the geobiochemical processes of the biosphere and storage turnover times. Transformities for these water storages varied between 3.54 E3 sej/J (water vapor) and 1.05 E6 sej/J (glaciers). Calculated transformities for global water flows ranged from 3.96 E3 sej/J (precipitation) to 9.55 E5 sej/J (ice melt).; Regional transformities of water resources reflected specific conditions of the landscape. The mean transformities for water in estuaries, rivers, lakes, wetlands and deep groundwater storages in Florida were calculated at 3.19 E4, 4.26 E4, 5.64 E4, 7.09 E4 and 1.66 E5 sej/J, respectively.; Eight local water supply utilities in Florida were evaluated to determine the emergy cost of producing potable water. Potable water transformities ranged from 1.39 E5 (West Palm Beach plant) to 1.39 E6 (Stock Island reverse osmosis plant). Five home water purification processes were evaluated to compare the emergy costs of producing potable water just for drinking, yielding transformities between 5.19 E6 (filtered water) and 3.16 E7 sej/J (bottled water).; To test theories of the appropriate use of water to maximize economic vitality, a computer model of a generalized regional production function was simulated. Using Florida as a case study, maximum total production occurred when the economic/urban sector, the agricultural sector, and the environment received approximately 25, 30, and 45%, respectively, of the fresh water remaining after evapotranspiration.; Since the calculated transformities for potable water are equivalent in magnitude to gasoline and electricity, the use of potable water should correspond with its high value. Therefore, measures need to be taken at local and regional levels to use potable water more appropriately. |
