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Chapter 14. Water: A Limited Resource. The Importance of Water. Water: shapes continents moderates our climate is essential for all living organisms. The Importance of Water. Composition and polarity. Hydrogen bonding properties. Properties of Water. The Importance of Water.
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Chapter 14 Water: A Limited Resource
The Importance of Water • Water: • shapes continents • moderates our climate • is essential for all living organisms
The Importance of Water Composition and polarity Hydrogen bonding properties • Properties of Water
The Importance of Water • Properties of Water Chemical composition of seawater
The Importance of Water • The Hydrologic Cycle
The Importance of Water • Our Supply of Fresh Water
The Importance of Water • Types of water: • surface water • runoff • drainage basin • groundwater • aquifers
The Importance of Water • Largest watersheds
The Importance of Water • Aquifers
Water Use and Resource Problems • Problems fall into 3 categories: • Too much • Too little • Poor quality / contamination (Chap. 22)
Water Use and Resource Problems • Too Much Water • Removing vegetation and constructing buildings increases flooding potential on flood plains
Water Use and Resource Problems Channelization • Too Much Water • Flood Management
Water Use and Resource Problems • Too Much Water • Flood Management Levees with natural river
Water Use and Resource Problems • Case-in-Point: The Floods of 1993
Water Use and Resource Problems • Too Little Water • Droughts • Overdrawing Surface Waters • Aquifer depletion • Causes subsidence • Can lead to saltwater intrusion
Water Use and Resource Problems • Saltwater intrusion
Water Use and Resource Problems • Too Little Water • Droughts • Overdrawing Surface Waters • Aquifer depletion • Causes subsidence • Can lead to saltwater intrusion • Salinization of Irrigated Soil
Water Problems in the US • Surface Water • Most problems in the West and Southwest • Aqueducts transport water from distance sources
Water Problems in the US • Examples of problems: • Mono Lake • The Colorado River • Basin Surface Water
Water Problems in the US • Groundwater • Aquifer depletion
Water Problems in the US • Groundwater • Aquifer depletion • - Ogallala Aquifer
Global Water Problems • Water distribution globally is very inequitable • In addition, stable runoff varies • Drinking Water Problems • 1.4 billion lack safe water • 2.9 billion lack proper wastewater disposal
Global Water Problems • Population Growth and Water Problems • India – 8,000 villages have no local water • China – water table falling 2-3 m / year • Pakistan – lack of water led to riots in 2001 • Mexico – water table falling 3.5 m / year in Mexico City
Global Water Problems The Rhine River Basin • Sharing Water Resources among Countries
Global Water Problems 1997 • Sharing Water Resources among Countries The Aral Sea 1976
Global Water Problems • Potentially Volatile International Water Situations • Jordan River • Nile River Sharing Water Resources among Countries
Water Management • Providing a Sustainable Water Supply • Sustainable water use seeks to provide water to future generations without damaging ecosystems.
Water Management • Providing a Sustainable Water Supply • Dams and Reservoirs • Pros – • Ensure year-round water supply • Hydropower • Recreation
Water Management • Providing a Sustainable Water Supply • Dams and Reservoirs • Cons – • Alter ecosystems • Sediment Deposition
Water Management • Providing a Sustainable Water Supply • Dams and Reservoirs • Example: Effect of dam on Colorado River in Grand Canyon
Water Management • Providing a Sustainable Water Supply • Water Diversion Projects
Water Management Condenses Simplified process: Produces steam Pure water is collected Water boiled Salt water • Providing a Sustainable Water Supply • Desalinization Two methods: 1) Distillation
Water Management Pressure salt H2O • Providing a Sustainable Water Supply • Desalinization Two methods: 1) Distillation 2) Reverse osmosis Salt impermeable membrane Salt water Fresh water
Water Conservation Drip or trickle irrigation • Reducing Agricultural Water Waste
Water Conservation Recycling water Xeriscaping • Reducing Agricultural Water Waste • Reducing Water Waste in Industry Reducing Municipal Water Waste