Environmental Biology quiz 3

Distribution of precipitation

influences plant communities, human activities

Lakes

Large bodies of inland surface water, formed asa result of a number of processes

Watershed

area of land that drains water to particular stream, river, or lake

Wetland

Lands transitional between terrestrial and aquatic systems where the water table is usually at or near the surface or the land is covered by shallow water

Ground Water

Water that flows or seeps downward and saturates soil orrock, supplying springs and wells

Groundwater Challenges

Excessive pumping can lead to depletion

In coastal areas, can have saltwater intrusion

Potential contamination by multiple human activities

Precipitation Patterns in the U.S

Highest:Pacific Northwest, Southeast, and Northeast (moist climates)

Lowest:Southwest and interior West (deserts like Nevada, Arizona)

Top 2 sectors in US

1. Agriculture (irrigation)

2. Thermoelectric power generation

Freshwater Withdrawal Trends

Per capita withdrawals have declined since 1980, mainly due to better efficiency and water-saving technologies in industry and agriculture.

Global Water Access

~2 billion people lack safely managed drinking water

~3.5-4 billion people lack safely managed wastewater services

Water Use Conflict (Southeastern U.S.)

*Tri-State Water Wars between Georgia, Alabama, and Florida over

*Apalachicola-Chattahoochee-Flint (ACF) River Basin - dispute over water allocation and ecological impacts.

Environmental Impacts of Dams

• Block fish migration

• Alter river flow and sediment transport

• Flood ecosystems and displace communities

Water Footprint

• The total volume of freshwater used to produce goods/services.

*Ways to reduce:

• Eat less meat

• Fix leaks

• Use efficient appliances

• Reduce food and textile waste

Regions Experiencing Water Stress

U.S.:Southwest (California, Arizona)

Global:Middle East, North Africa, parts of India and Australia

Pollution Sources

Point Source: From a single, identifiable location (e.g., factory pipe, wastewater plant)

Nonpoint Source: From diffuse areas (e.g., agricultural runoff, stormwater)

Eutrophication

Cause: Excess nutrients (nitrogen, phosphorus) → algal blooms

Impacts:

1. Decreased oxygen → fish kills

2. Loss of biodiversity / dead zones

Measuring Water Quality

1. Physical: (temperature, turbidity)

2. Chemical: (pH, nutrient levels, dissolved oxygen)

3. Biological: (presence of bacteria or aquatic life)

Clean Water Act (1972)

Agency: U.S. Environmental Protection Agency (EPA)

Point sources:Regulated through permits (NPDES)

Nonpoint sources: Managed with voluntary programs and state/local initiatives

Safe Drinking Water Act

Safe Drinking Water Act

"Multiple Barrier" approach:Protect water from source → treatment → distribution

Lead control: Emphasizes corrosion control and replacing lead pipes

Wastewater Management

*Urban areas: Centralized treatment plants (like Messerly in Augusta)

*Rural areas: Septic tanks or small-scale systems

*Challenges:

• Aging infrastructure

• Combined sewer overflows during heavy rain

*Innovations:

• Green infrastructure (bioswales, rain gardens)

• Water reuse and recycling systems

Agricultural Runoff

Nonpoint source pollution

*Solutions:

• Buffer strips, cover crops

• Reduce fertilizer use

• Improve irrigation efficiency

Water Quality Impairments in Georgia

Most common cause:

Nonpoint source pollution, especially sediment and nutrient runoff from agriculture.

Gulf of Mexico Hypoxia

Major contributors: Nitrogen and phosphorus from

Midwestern agriculture via the Mississippi River

• Causes seasonal dead zones with low oxygen.

Great Lakes & Gulf of Mexico Problems

Lake Erie: Harmful algal blooms (nutrient pollution)

Gulf of Mexico:Hypoxic "dead zone"