Another 30 percent of freshwater is in the ground. Yet, rivers and lakes are the sources of most of the water people use everyday. One estimate of global water distribution Percents are rounded, so will not add to The Earth is a watery place.
But just how much water exists on, in, and above our planet? Read on to find out. Earth's water is always in movement, and the natural water cycle, also known as the hydrologic cycle, describes the continuous movement of water on, above, and below the surface of the Earth. Water is always changing states between liquid, vapor, and ice, with these processes happening in the blink of an eye and over millions of years.
A huge amount of water exists in the ground below your feet, and people all over the world make great use of it. But it is only found in usable quantities in certain places underground — aquifers. Read on to understand the concepts of aquifers and how water exists in the ground. The atmosphere is the superhighway in the sky that moves water everywhere over the Earth. Water at the Earth's surface evaporates into water vapor which rises up into the sky to become part of a cloud which will float off with the winds, eventually releasing water back to Earth as precipitation.
Ice and glaciers are part of the water cycle, even though the water in them moves very slowly. Ice caps influence the weather, too. The color white reflects sunlight heat more than darker colors, and as ice is so white, sunlight is reflected back out to the sky, which helps to create weather patterns.
Read on to learn how glaciers and ice caps are part of the water cycle. Our interactive diagrams allow you to "mouse around" the parts of the water cycle and view explanations, pictures, and more.
The ground stores huge amounts of water and it exists to some degree no matter where on Earth you are. Lucky for people, in many places the water exists in quantities and at depths that wells can be drilled into the water-bearing aquifers and withdrawn to server the many needs people have. Freshwater on the land surface is a vital part of the water cycle for everyday human life. On the landscape, freshwater is stored in rivers, lakes, reservoirs, and creeks and streams.
Most of the water people use everyday comes from these sources of water on the land surface. Not only do the oceans provide evaporated water to the water cycle, they also allow water to move all around the globe as ocean currents.
Oceans are the storehouses of water nature uses to run the water cycle. Glaciers are a big item when we talk about the world's water supply. Almost 10 percent of the world's land mass is currently covered with glaciers, mostly in places like Greenland and Antarctica. You can think of a glacier as a frozen river, and like rivers, they "flow" downhill, erode the landscape, and move water along in the Earth's water cycle.
The U. This photograph depicts several examples of geological features along the California coastline that are shaped by varied coastal processes. The gently sloping beach, stark bluffs, and presence of smooth rocks suggests that the coastal processes shaping this coastline are complex.
Imperial Geyser looking south. Access to freshwater by poor neighborhoods in urban areas remains a challenge in Brazil. The renewable fresh water bodies in Russia include rivers, lakes, and man-made reservoirs. Lake Baikal , the largest and deepest freshwater lake in the world, is located in Russia. The lake was formed on a rift. Baikal harbors a large population of seals.
In total, Russia has 4, cubic kilometers of fresh water resources. The volume of renewable fresh water resources in the US is approximately 3, cubic kilometers. Most of the fresh water resources in the country are surface water. Majority of freshwater bodies in the United States are lakes. Other fresh water sources are rivers, ponds, and reservoirs. There are thousands of lakes in the US, including the world-famous Great Lakes.
The volume of renewable fresh water in Canada is approximately 2, cubic kilometer. Besides, the fresh water is mostly underground, in small ponds or in glaciers. The USGS Web site defines a river's length as "the distance to the outflow point from the original headwaters where the name defines the complete length. The land that is upgradient of any point on the river is known as the drainage basin or watershed.
Ridges of higher land, such as the Continental Divide, separate two drainage basins. Flowing water is extremely powerful and plays an important role in creating the landscape and in humans' lives.
Flowing water is used for numerous reasons including irrigation and hydroelectric power production. Rivers erode the landscape and change the topography of the Earth by carving canyons and transporting soil and sediment to create fertile plains.
Rivers carry soil and sediment that have been washed into the river when it rains or snow melts. The faster the water moves, the larger the particle size the river is capable of carrying. The USGS measures how much sediment a river carries by measuring the streamflow, or the amount of water flowing past a given site; and the sediment concentration.
Sediment in the river can be helpful and harmful. Sediment, when deposited on the banks and in the flood plain, makes excellent farmlands. However, sediment can harm and even destroy dams, reservoirs and the life in the stream. Also, during floods, these sediments can be left behind as sticky, smelly mud in unwanted places.
Measuring the streamflow is accomplished by determining the stream stage and the stream discharge. The stream stage, or datum, is the height of the water surface, in feet, above an arbitrary reference point. The stream discharge is a measurement of the amount of water that is flowing at a particular point in time.
It is measured in cubic feet per second. A discharge measurement determines the amount of water that is flowing in the river at any given stream stage. In order to make this measurement, the width of the river, and the water's depth and velocity at various points must be measured at several different stream stages. A cross-section of the river is divided into intervals and the area of each interval is calculated.
If the velocity was measured at different depths on the same vertical interval, then the velocity is averaged. To determine the discharge for the interval, the area is multiplied by the velocity. To find the entire stream's discharge, an average of all the intervals' discharges is calculated.
It is important to take discharge measurements of the stream at various stream stages, even flood stage. A river reaches flood stage when the river overflows its banks. The flood stage can be determined by measuring the gage height, or simply the height of the water in the stream measured from the river's bottom. The streamflow can increase exponentially as the gage height increases. Thus, a small increase in gage height may indicate that a river has reached its flood stage. Floods are a fairly common, yet dangerous, natural disaster.
They normally occur because a storm or rapid snow melt has produced more runoff than a stream can carry. Dams failing, landslides blocking stream channels, and high tides are some other causes of flooding. Weather patterns can greatly influence when and where flooding will occur. By studying these patterns, geologists can determine the susceptibility of a region to having a flood at certain times of the year. The recurrence interval, measured in years, describes the magnitude of a flood.
Changes in the drainage basin, such as harvesting timber or housing developments, can change the magnitude of a flood. The normally dry land that becomes covered with water during a flood is known as the flood plain.
Restrictions on land use in flood plains is regulated by flood-plain zoning. Dams and levees have been built to help reduce damage caused by floods. When flowing water travels to an area of land that is completely surrounded by higher land, a lake is formed.
The water is not trapped in this low area, the water just escapes at a slower rate than the rate of incoming water. Lakes can vary greatly in area, depth, and water type. Most lakes are fresh water, however some, such as the Great Salt Lake and the Dead Sea, are salt water. Contrary to common belief, a reservoir is not the same as a lake.
A reservoir is a manmade lake caused by a river being dammed. The water in a reservoir is very slow moving compared to the river. Therefore, the majority of the sediments that the river was carrying settle to the bottom of the reservoir.
A reservoir will eventually fill up with sediment and mud and become unusable. The hydrologic cycle or water cycle is a graphic representation of how water is recycled through the environment. Water molecules remain constant, though they may change between solid, liquid, and gas forms.
Drops of water in the ocean evaporate, which is the process of liquid water becoming water vapor. Evaporation can occur from water surfaces, land surfaces, and snow fields into the air as water vapor. Moisture in the air can condensate, which is the process of water vapor in the air turning into liquid water.
Water drops on the outside of a cold glass of water are condensed water. Condensation is the opposite process of evaporation. Water vapor condenses on tiny particles of dust, smoke, and salt crystals to become part of a cloud. After a while, the water droplets combine with other droplets and fall to Earth in the form of precipitation rain, snow, hail, sleet, dew, and frost.
Once the precipitation has fallen to Earth, it may go into an aquifer as groundwater or the drop may stay above ground as surface water. The hydrologic cycle is an important concept to understand.
Water has so many uses on Earth, such as human and animal consumption, power production, and industrial and agricultural needs. Precipitation—in the form of rain and snow—also is an important thing to understand.
It is the main way that the water in the skies comes down to Earth, where it fills the lakes and rivers, recharges the underground aquifers, and provides drinks to plants and animals. Different amounts of precipitation fall on different areas of the Earth at different rates and at various times of the year.
One problem facing the cycle of water on Earth is water contamination. Chemicals that go into the water often are very difficult, if not impossible, to remove.
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