ENVS200-WK7.1-water2
Page 1: Introduction
Groundwater significance highlighted through illustrations.
Page 2: Student Learning Objectives
Understand differences between aquifers and aquitards.
Identify various types of wells and springs.
Explain degradation and depletion of groundwater.
Discuss negative consequences of groundwater overuse, dams, and water transport.
Page 3: Groundwater Characteristics
Porosity: Ability of rocks to contain fluids.
Permeability: Ability of rocks to allow fluids to pass through.
Page 4: Groundwater Flow
Groundwater behavior influenced by geology and geometry of rocks/sediments.
Aquifers: High permeability and porosity, facilitating easy water flow.
Aquitards: Low permeability, slowing or preventing water motion.
Page 5: Global Groundwater Distribution
Visuals show the insufficient vs. sufficient groundwater supply around oceans.
Page 6: Accessing Groundwater
Groundwater accessed via:
Natural springs
Human-made wells
Page 7: Springs
Springs are where the water table meets the surface
Often found in valleys with wetland vegetation and saturated soils year-round.
Page 8: Types of Wells
Ordinary Wells: Holes into an aquifer, requiring pumping.
Artesian Wells: Water rises on its own due to pressure.
Page 9: Ordinary Wells
Water seeps into ordinary wells up to the water table level, requiring additional means for lifting water.
Page 10: Artesian Wells
These wells are specifically designed to access groundwater under pressure, allowing water to reach the surface without pumping.
Page 11: Groundwater Simulations
Engaging illustrations and simulations representing groundwater dynamics.
Page 12: Water Sufficiency Concerns
Freshwater being used unsustainably through
Faster extraction than natural replenishment
Wasting and polluting water resources.
One in ten people lacks access to clean water.
Page 13: Water Resources
Surface Water: Freshwater from rain and snow.
34% of reliable surface runoff utilized annually.
70% for agriculture, 20% industrial use, and 10% urban usage.
Indirect water usage contributes significantly to global water footprints.
Page 14: Causes of Water Scarcity
Factors: Dry climate, drought, overuse, inefficient water use.
Freshwater scarcity stress relates to availability versus human demand.
Global water basins often shared among multiple countries, sometimes contentiously.
Page 15: River Basins and Water Scarcity Stress
Different major river basins exhibit varying levels of freshwater scarcity stress.
Page 16: Water Quality Threats
Global quality and quantity of freshwater supplies are threatened.
1.2 billion people lack access to clean drinking water.
Over-extraction causes lowering of water tables, drying springs, and seawater intrusion.
Page 17: Global Water Demand vs. Supply
Rapid population growth leads to high water demand with limited new sources available.
Page 18: Average Annual Precipitation
Statistics on average annual precipitation across various regions.
Page 19: California Water Engineering
About 70% of rivers engineered to move water between Northern and Southern California.
Key projects: Los Angeles Aqueduct, California Aqueduct, Colorado River Aqueduct.
Page 20: Future Water Resources
Groundwater over-extraction threatens food production and urban supply.
Water transfer projects can disrupt ecosystems but expand distribution.
Desalination is an expensive but viable option for augmenting freshwater supplies.
Page 21: Consequences of Over-Use
Over-pumping limits food supply and raises prices, impacting affordability.
Lowering water tables necessitates deeper and costlier wells.
Page 22: Water Table Dynamics
Overextraction leads to cone of depression around wells, affecting availability.
Page 23: Wells Running Dry
Wells may run dry before complete depletion of the water table occurs, prompting deeper installations.
Page 24: Saltwater Intrusion
Occurs near coastlines, poisoning wells and rendering them unusable.
Page 25: Saltwater Dynamics
Freshwater density compared to saltwater affects intrusion; rapid extraction moves saline boundaries towards wells.
Page 26: Mitigation Strategies
Pumping treated freshwater back into the ground to prevent saltwater intrusion.
Page 27: Aquifer Compaction
Post-extraction, sediments undergo readjustment, leading to compaction and decreasing porosity.
Page 28: Consequences of Compaction
Compaction can cause land subsidence and irreversible damage to infrastructure.
Page 29: Infrastructure Damage
Subsidence leads to destruction of essential structures without hope of recovery.
Page 30: Subsidence Statistics
Illustrative measurements of subsidence in California show significant vertical changes.
Page 31: Sinkholes
Rapid subsidence due to groundwater removal leads to dangerous ground collapses.
Page 32: Groundwater Contamination
Often unnoticed until significant damage occurs; cleanup is slow and expensive.
Page 33: Sources of Pollution
Common contaminants: fertilizers, animal sewage, industrial waste affecting aquifers.
Page 34: Dams and Water Transfer
Dams block river flow, creating reservoirs; vital for water management.
Page 35: Advantages of Dams
Benefits include flood control, irrigation, electricity generation, and recreation.
Page 36: Disadvantages of Dams
Dams displace populations, flood lands, and disrupt ecosystem functions.
Average lifespan limits their effectiveness.
Page 37: Water Transfer Impact
Water transfer diminishes river flow, increases pollution, threatens fisheries, and promotes water wastage.
Page 38: Evaluating Dam Pros and Cons
Encouragement to consider the most impactful advantage and disadvantage concerning dams.
Page 39: Desalination Overview
Process of removing soluble salts from seawater; techniques include distillation and reverse osmosis.
Page 40: Desalination Drawbacks
High costs, chemical waste harming ecosystems, and significant brine production.
Page 41: Proposed Desalination Facility
Details of a desalination plant project near Huntington Beach with environmental considerations.
Page 42: Existing Desalination in California
Summary of California's desalination facilities, featuring the Carlsbad project as the largest.
Page 43: Future of Water Resources
Ongoing challenges related to aquifer depletion, water transfer impacts, and desalination costs.
Page 44: Freshwater Scarcity Stress
Factors influencing the assessment of freshwater availability against human consumption.
Page 45: Strategies for Water Supply Extension
Three main strategies: conservation, desalination, interbasin transfers to manage water resources effectively.
Page 46: California Water Project
Overview of a project aimed at enhancing water transport across the state.
Page 47: Supplementary Resources
Link to further information on water projects.
Page 48-49: Closing Remarks
Concluding content from the course related to water resource management.