ABSTRACT
The need for food and water would appear to be straightforward examples for the dependence of humanity on ecological conditions, as well as for the ecological changes wrought by human activities with the purpose of satisfying these needs. Earth is rightly considered the planet of water, only here does water naturally occur in all three states of matter, and even covers 71 percent of the planet's surface. Water is necessary for all life, as well as essential for the functioning of ecosystems which provide a host of services and natural capital, including an influence on the distribution and quality of the water itself. Non-extractive/in-stream benefits, e.g. transportation, hydroelectric generation, and dilution of pollutants, similarly depend on a flow of water of sufficient size; hygiene may not be an in-stream use anymore, but used to be. Agricultural, municipal, and industrial usage of water requires its diversion while the host of other benefits depends on sufficient water remaining in ecosystems.
