WATER - The Hydrosphere Objectives: Define “hydrosphere” Identify & describe the processes involved in the water cycle Describe 2 types of ocean currents Explain how the ocean regulates Earth’s temperature

The Hydrosphere All the water on or near Earth’s surface Oceans Lakes Rivers Wetlands Icecaps and icesheets Soil Subsurface groundwater Clouds and atmosphere

Water Cycle Review What are the main processes involved in the water cycle?

What powers the Water Cycle?

Water Cycle Involves Transfer of Energy Water absorbs heat energy When enough energy is absorbed, water changes from liquid to gas (evaporation) Energy is transferred from Earth’s surface to atmosphere 80% of water entering atmosphere originates from oceans between 60oN and 60oS latitude Water moves to a cooler area and condenses During condensation, water releases heat Warms surrounding atmosphere

The World Ocean 71% of Earth’s surface Key functions: 1. Absorb/store energy from sun 2. Regulate temperatures in atmosphere 3 zones based on temperature change: 1. Surface 2. Thermocline 3. Deep zone

Ocean Currents Circulate water (and heat and nutrients and gases) Water flows from: Warmer toward colder areas More dense toward less dense area Deep Ocean Currents

2 types of currents: 1. Surface – wind-driven currents 2. Deep – density-driven currents

Oceans Regulate Global Temperatures Water absorbs/releases heat more slowly than land Temperature of atmosphere changes more slowly Currents that circulate warm water (ex. Gulf Stream) cause land areas they flow past to have more moderate climate Gulf Stream Animation

WATER RESOURCES OBJECTIVES – Identify where Earth’s water is stored Explain why water is considered a limited resource Compare surface water resources and groundwater

TWO TYPES OF WATER SURFACE WATER – freshwater on Earth’s land surface Lakes, river, streams, wetlands GROUNDWATER – freshwater beneath Earth’s surface In sediments and rock formations

SURFACE WATER – IT STARTS WITH A DROP Buba River, Guinea-Bissau SURFACE WATER – IT STARTS WITH A DROP Precipitation falls to the ground, then flows into streams, streams flow into rivers, rivers flow into larger rivers RIVER SYSTEM – flowing network of rivers moving across land

WATERSHEDS OF THE WORLD WATERSHED – the area of land drained by a river affected by – melting snow & rain, use, lack of rain and POLLUTION ANYWHERE IN THE WATERSHED Weekly Average Flow of World Watersheds

GROUNDWATER Forms when surface water percolates / infiltrates through soil into the rocks below Essential for human survival – most freshwater is underground

WATER TABLE Place below ground where ground is saturated with water

An underground formation that contains water Water table forms upper boundary of aquifer Important water sources for cities & agriculture

Aquifers

Porosity How much space (pores) or holes found in rock Where water can flow through Porous rock can hold lots of water

Permeable vs. Impermeable The ability of rock or soil to allow water to flow through it Sand and gravel are permeable Clay and blacktop are impermeable

Recharge Zone Area of Earth’s surface through which water percolates down into aquifer Environmentally sensitive – any pollution in recharge zone can enter the aquifer

Aquifers can take tens of thousands of years to recharge/refill What could interfere with recharge?

Well – a hole dug or drilled to reach water More reliable as a source of water than surface water and cleaner. WHY??? Drilled to reach below water table…WHY? What happens if water is removed faster than it can be recharged?

Water Use & Management We all live downstream.

Section 2 : Water Use and Management GOALS: Identify how water is used in home, industry and agriculture. Explain how and why water is treated before coming to your home. Describe ways to increase water supplies Identify ways to conserve water TERMS: potable, pathogen, dam, reservoir, desalinization

Aylito Binayo's feet know the mountain Aylito Binayo's feet know the mountain. Even at four in the morning she can run down the rocks to the river by starlight alone and climb the steep mountain back up to her village with 50 pounds of water on her back. She has made this journey three times a day for nearly all her 25 years. So has every other woman in her village of Foro, in the Konso district of southwestern Ethiopia. Binayo dropped out of school when she was eight years old, in part because she had to help her mother fetch water from the Toiro River. The water is dirty and unsafe to drink; every year that the ongoing drought continues, the once mighty river grows more exhausted. But it is the only water Foro has ever had.

783 million people do not have access to clean water almost 2.5 billion do not have access to adequate sanitation 6 to 8 million people die annually from the consequences of disasters and water-related diseases

How Much Water Do You Use Average person in US uses ~100 gpd Average person in India~ 40 gpd

What can you learn from this chart?

Making Water Safe Potable: safe to drink Most water needs to be treated Pathogens: organisms that cause diseases Bacteria, viruses, worms

Drinking Water Treatment

Uses of Water Industrial Water Use 19% of worldwide water use To make “stuff” Dispose of waste Cooling power plants (most)

Uses of Water Agriculture: 67% of worldwide water use Irrigation: providing water to plants )other than by precipitation) 80 gallons to produce 1 ear of corn 1 lb. beef = 1,000 gal. LOTS OF WATER

Irrigation Where does all this water come from?

From the ground – the figure shows ground subsidence (sinking) 1925-1977 due to removal of groundwater - 9 meters or 29 feet or 7 inches per year! WHY? To grow our food

Water Management Humans have altered water flow for thousands of years Engineering Dams, canals, pipes, towers bring water to where it is needed

California aqueduct brings water hundreds of miles, across deserts, mountains

Dams and Reservoirs Reservoir: an artificial lake often behind a dam Flood control Recreation Water supply Drinking irrigation Generate electricity 20% worldwide

Pros and Cons of Dams Downstream cropland and Large losses of water through evaporation Flooded land destroys forests or cropland and displaces people Downstream flooding is reduced Downstream cropland and estuaries are deprived of nutrient-rich silt Reservoir is useful for recreation and fishing Can produce cheap electricity (hydropower) Migration and spawning of some fish are disrupted Provides water for year-round irrigation of cropland

Water Conservation Fastest, easiest way to increase water supplies is to use less water Agriculture Industry At home What are some ways you can conserve water?

Irrigation As much as 80% normally evaporates Drip Irrigation, reduces that number greatly

Industry Recycling Cooling water Wastewater

Desalinization Removing salt from salt water Has a lot of promise Very energy intensive Very expensive What to do with waste? Future?

Transporting Water The Nordic Water Supply Company in Oslo, Norway, has signed a contract to deliver 7 million cubic meters of water per year in bags to northern Cyprus.

Section 2 Review Identify how water is used in home, industry and agriculture. Explain how and why water is treated before coming to your home. Describe ways to increase water supplies Identify ways to conserve water TERMS: potable, pathogen, dam, reservoir, desalinization

Section 3: Water Pollution GOALS: Compare point-sources and non-point sources of water pollution Describe the 5 classifications of water pollution Explain why it is difficult to clean up groundwater What does the Clean Water Act do? TERMS: water pollution, point-source, non-point source, wastewater, biomagnification, eutrophication

Freshwater animals are vanishing faster than those on land or at sea.

What is Water Pollution? Water Pollution: is the introduction of chemical, physical, or biological substances that affects organisms that depend upon it Many types of water pollution

Point Source Pollution coming from one single place Leaking tanker Pipe from a factory Leaking underground storage tank Can easily be identified and traced

Point Sources – easily identified

Non-Point Source Comes from various sources that are hard to identify and may be spread over a large area Runoff from farms Runoff from cities Difficult to identify Hard to control HUGE PROBLEM – accounts for 96% of water pollution

How can a farmer in Montana affect a shrimp farmer in Louisiana? NON-Point

Point vs Non-Point NONPOINT SOURCES Rural homes Cropland Urban streets Suburban development Wastewater treatment plant Rural homes Cropland Factory Animal feedlot POINT SOURCES

Principal Water Pollutants

Types of Water Pollution 1) Wastewater Water that flows down the drain What’s in it? Where does it go? (out-of-sight, out-of-mind) Is it harmful?

Sewage Sludge – can be toxic

2) Eutrophication Natural process – however - Too many nutrients (N & P) in the water causes algal blooms and decreased oxygen in water Causes “dead zones” in water Little or no oxygen

Artificial or Cultural Eutrophication

3) Thermal Pollution Occurs when temperature of water rises rapidly Power plants Factories cooling equipment Causes fish kills Decreases oxygen in water – suffocates aquatic organisms

4) Groundwater Pollution Pollution that percolates down from land or surface water pollution Fertilizers, pesticides, leaking underground tanks Many leaking underground tanks

What would make groundwater pollution hard to clean up?

Groundwater Pollution What could happen if recharge zone is polluted? Common pollutants in recharge zone: 1. Nitrates 2. Petroleum products 3. Pesticides 4. Heavy metals 5. Industrial pollutants

Difficulties with cleaning groundwater pollution: 1. Recharge is very slow; 100s – 1000s years to recycle 2. Water dispersed over large areas 3. Pollutants can cling to particles that make up aquifer Best course of action is to prevent groundwater pollution

5) Ocean Pollution Pollutants directly or indirectly put into oceans 85% of ocean pollution is land based Oil spills Runoff River pollution Cruise Ships Development along coasts Increasingly a problem

15 BIGGEST OIL SPILLS

Water Pollution and Ecosystems Can cause immediate damage to an ecosystem Effects can be far reaching Some pollutants build up (they do not decompose quickly) Biomagnification is the accumulation of pollutants at successive levels of the food chain. Biomagnification has alarming consequences for organisms at the top of the food chain, and is one reason why U.S. states limit the amount of fish people can eat from certain bodies of water.

Biomagnification

in an individual in a food chain

Cleaning Up Water Pollution 1969 Cuyahoga River in Cleveland caught fire 1972 Congress passes Clean Water Act 1970s Environmental Activism/Awareness

Cleaning Up Water Pollution Clean Water Act of 1972 was to “restore and maintain the physical, chemical and biological integrity of the nation’s water.” Fishable and Swimmable Better, but… still many polluted water bodies

Cleaning Up Water Pollution

CLEAN WATER ACT (1972) “to restore and maintain the chemical, physical and biological integrity of the nations water’s” goal – to make all surface water clean enough for fishing and swimming by 1983

Section 3 Review GOALS: Compare point-sources and non-point sources of water pollution Describe the 5 types of water pollution Explain why it is difficult to clean up groundwater What does the Clean Water Act do? TERMS: water pollution, point-source, non-point source, wastewater, biomagnification, eutrophication

Chapter 11 Review Describe where Earth’s water resources are located. How is Earth’s water a limited resource? How can we manage our water resources better? What are the main causes and impacts of water pollution?

What does the future hold for water on planet Earth? Climate Change? Melting Glaciers? Human Population rising? Water Scarcity?

Types of pollution Wastewater Groundwater Eutrophication Thermal Ocean