"Water resources are natural resources of water that are potentially useful for humans..."
The study of water usage for crop irrigation, water conservation practices, and water quality management to maintain healthy ecosystems.
"97% of the water on Earth is salt water..."
"...only three percent is fresh water..."
"...slightly over two-thirds of this is frozen in glaciers and polar ice caps."
"Natural sources of fresh water include surface water, under river flow, groundwater and frozen water."
"Artificial sources of fresh water can include treated wastewater (wastewater reuse) and desalinated seawater."
"Human uses of water resources include agricultural, industrial, household, recreational, and environmental activities."
"Water resources are under threat from water scarcity, water pollution, water conflict, and climate change."
"Fresh water is a renewable resource..."
"...with depletion occurring most prominently in Asia, South America, and North America..."
"...although it is still unclear how much natural renewal balances this usage..."
"...water pollution..."
"...mainly as groundwater..."
"...only a small fraction present above ground or in the air."
"...surface water, under river flow, groundwater and frozen water."
"Human uses of water resources include agricultural, industrial, household, recreational, and environmental activities."
"...depletion occurring most prominently in Asia, South America, and North America..."
"...whether ecosystems are threatened."
"...slightly over two-thirds of this is frozen in glaciers and polar ice caps."
"...the world's supply of groundwater is steadily decreasing..."