4 (b) Precipitation
Water that falls to Earth as rain, snow, hail, or sleet is called precipitation.
Most precipitation falls directly into the ocean. The precipitation that falls on land may evaporate immediately or run off the surface into rivers and lakes. From there, it may evaporate or flow back into the ocean. In addition, some water may trickle down into the ground. After a long time, this groundwater may reach a river, lake, or ocean and continue the cycle by evaporating again.
Precipitation is the source of all fresh water on and below Earth’s surface. The water cycle renews the usable supply of fresh water on Earth. For millions of years, the total amount of water on Earth has remained fairly constant—rates of evaporation and precipitation are balanced.
Most precipitation falls directly into the ocean. The precipitation that falls on land may evaporate immediately or run off the surface into rivers and lakes. From there, it may evaporate or flow back into the ocean. In addition, some water may trickle down into the ground. After a long time, this groundwater may reach a river, lake, or ocean and continue the cycle by evaporating again.
Precipitation is the source of all fresh water on and below Earth’s surface. The water cycle renews the usable supply of fresh water on Earth. For millions of years, the total amount of water on Earth has remained fairly constant—rates of evaporation and precipitation are balanced.
