| A | B |
|---|
| Water on Earth is | 97.5 saltwater |
| fresh water | water that is relatively pure with few dissolved salts |
| surface water | water found on Earth's surface |
| runoff | water that flows over land; not absorbed into the ground |
| river system | network of connected streams and rivers |
| all of the land that supplies water to a particular river system | watershed |
| water found below Earth's surface | groundwater |
| permeable | having pores through which water can pass |
| having few or no pores; water cannot pass through | impermeable |
| aquifers | sponge-like formations of rock, sand, or gravel that hold water |
| boundary between zone of aeration and zone of saturation | water table |
| recharge zone | any area where surface water soaks into the ground and reaches an aquifer below |
| a hole dug into an aquifer | well |
| BIGGEST use of freshwater worldwide | agriculture |
| Second largest used of freshwater worldwide | industrial |
| smallest use of freshwater worldwide | personal |
| the process of moving water from its source to places where humans use it | water diversion |
| an obstruction placed in a river or stream to block its flow | dam |
| reservoirs | large, artificial lakes that store water for human use |
| consequence of over-diverting water | dried up rivers; damaged ecosystems |
| salinization | buildup of salts in the surface layers of soil |
| desaliniation | removal of salts from saltwater |
| xeriscaping | landscaping using plants that require little water |
| point-source pollution | pollution coming from an identifiable point |
| nonpoint-source pollution | pollution that comes from a large area |
| cultural eutrophication | excessive nutrient pollution due to human activity |
| wastewater | water that has been used by people in some way |
| sudden explosion of algal growth | algal bloom |
| sediment pollution | excessive sediments in a body of water |
| water that has been returned to its source at a higher temperature than it began | thermal pollution |
| pathogens | disease-causing organisms or viruses |
| biological polllution | pollution caused by pathogens |
| types of ocean pollution | oil, toxic chemicals, nutrients |
| red tide | algal bloom from algae that produce reddish-brown pigments |
| first step of drinking water treatment process | filtration |
| step of water treatment process that kills pathogens | chlorination |
| septic systems | method of waste treatment generally used in rural areas |
