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The Hydrosphere. Hydrosphere. The hydrosphere includes all of the water on or near the Earth’s surface. This includes water in the oceans, lakes, rivers, wetlands, polar ice caps, soil, rock layers beneath Earth’s surface, and clouds. The Water Cycle.
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Hydrosphere • The hydrosphere includes all of the water on or near the Earth’s surface. • This includes water in the oceans, lakes, rivers, wetlands, polar ice caps, soil, rock layers beneath Earth’s surface, and clouds.
The Water Cycle • The water cycleis the continuous movement of water from the ocean to the atmosphere to the land and back to the ocean.
Earth’s Oceans • All of the oceans are joined in a single large interconnected body of water called the world ocean. The world ocean play important roles in the regulation of the planet’s environment.
Earth’s Ocean Basins • Pacific – largest and deepest ocean; single largest geographic feature on Earth • Atlantic – half the size of the Pacific • Indian – smaller than the Atlantic but has the same average depth • Arctic – 7% the size of the pacific and ¼ as deep as the other oceans
Ocean Water • The difference between ocean water and fresh water is that ocean water contains more salts. • Salinity is a measure of the amount of dissolved salts in a given amount of liquid. • The salinity can vary depending upon the amount of rain, temperature, and freshwater that flows into the ocean. • Deep water has a higher salinity because it is colder.
Global Temperature Regulator • One of the most important functions of the world ocean is to absorb and store energy from sunlight which in turn regulates temperatures in Earth’s atmosphere. • If the ocean did not regulate atmospheric and surface temperatures, temperatures would be too extreme for life to exist on Earth.
El Nino and La Nina El Nino- an episode-occurring every 3 to 7 years- of ocean warming that affects the eastern tropical Pacific; warm counter currents become usually strong and replace normally cold off shore waters with warm equatorial waters. Marked by abnormal weather patterns in Equador and Peru. La Nina- surface conditions in eastern Pacific are colder than average; can increase hurricane activity.
Freshwater Fresh water is water that contains insignificant amounts of salts. It makes up 3% of the Earth’s water supply. Most of the fresh water is locked up in icecaps and glaciers while the rest is found in places like lakes, rivers, wetlands, the soil and atmosphere. A river system is a network of streams that drains an area of land and contains all of the land drained by a river including the main river and all its smaller streams or rivers that flow into larger ones, or tributaries.
Running Water Streams are most important agents of erosion The ability of a stream to erode and transport depends on its velocity.
Running Water • Factors that determine velocity: • Gradient - the slope or steepness of a stream channel. The steeper the gradient, the more energy the stream has as it flows downhill. • Channel characteristic - the course the water in a stream follows. As the water flows, it encounters friction from the sides and the bottom. The amount of friction is affected by the shape, size, and roughness of the channel. • Discharge - the volume of water flowing past a certain point in a given unit of time.
River Basin • A large area that drains to the ocean • Ex. Catawba River Basin • Water Shed- a smaller area that drains to a certain area. • Aquifer- An underground (groundwater) water source that we use • Water quality of NC chemical, physical and biotic index
Groundwater Rain and melting snow sink into the ground and run off the land. Most of this water trickles down through the ground and collects as groundwater. Although it makes up only 1 percent of all the water on Earth, groundwater fulfills the human need for fresh drinking water, and supplies agricultural and industrial need.
Clean Water – A Life Sustaining Liquid Remember that freshwater makes up a very small fraction of all water available on Earth.
Sources of Point Pollution 23 million septic-tank systems 190,000 storage lagoons for polluted waste 9,000 municipal landfills About 2 million underground storage tanks containing pollutants such as gasoline Thousands of public and industrial wastewater treatment plants Sources of Nonpoint Pollution Highway construction and maintenance eroding soil and toxic chemicals Storm-water runoff from city or suburban streets: oil, gasoline. Dog feces, litter Pesticides from 112 million hectares of cropland treated with these substances each year. 50 million tons of fertilizer applied to lawns and crops 10 million tons of dry salt applied to highways for snow and ice Where does water pollution come from?
Wells Wells are dug or drilled to tap into underground water. With a “dug” well it is hard to prevent contamination of the water. Drilled wells are made into underground aquifers. These are lined, sealed, and do a much better job of keeping out microorganisms and chemicals.
Problems with Wells Contamination by microorganisms or by chemicals. Soil salination – as the water table drops, the salt in the soil dries out which can cause a problem for nearby vegetation.
Aquifer Depletion Salt water intrusion-occurs when salt water moves in where fresh water should be located. Subsidence- When the land level falls due to loss of groundwater.
Dams and Dam Removal • Dams are used to provide drinking water, water for agriculture, generate hydroelectric power, and recreational opportunities. • Dams can also cause problems: • Flooding of natural habitats upstream • Fragmentation of migratory fish population • Sedimentation behind dam can cause there to be less water available for hydroelectric power • reservoir is a breeding ground for disease causing insects like mosquitoes. • Disrupts the natural flow of streams and rivers.
Dam Removal • Dam removal benefits • Avoid catastrophic dam failure • Benefit aquatic life and migratory fish • Restore downstream habitats • Restore the natural flow of streams and rivers
Importance of Water Conservation • Goals of water conservation • Sustainability: withdrawal of water should not exceed its natural replacement rate • Energy conservation: pumping and treating water takes a lot of energy • Habitat conservation • Reduce water consumption per capita – use water more efficiently and responsibly.
