Water Pollution + Soils

Excess nutrients

• Phosphorus and nitrogen from fertilizers, detergents, sewage treatment plants

What are limiting nutrients and how do they impact eutrophication and hypoxia?

Nitrogen and phosphorus → excess nutrients into water → algae blooms → oxygen depletion → hypoxia 

How does stream-floodplain reconnection improve water quality?

Increases sediment filtration, improves water quality, and reduces pollutants.

What is denitrification and how can stream restoration enhance it?

Nitrate is converted into nitrogen gas - removes excess nitrogen → increases contact time w soils - reduce nutrient pollution - increased denitrification

How does acid rain affect water quality and alkalinization of streams and rivers (hint chemical weathering of rocks and soils by acid rain neutralize acids and produce alkaline ions like carbonates)?

Acid rain chemically weathers rocks → releases alkaline ions (carbonate, bicarbonate) - neutralize acidity - increase water alkalinity and buffer ph

Why is stream-floodplain restoration done in Maryland?

Reduces nutrient pollution entering the Chesapeake Bay, improves habitat, enhances flood resilience, and restores ecosystem functions.

What is the Clean Water Act? What does it protect?

U.S. law (1972) that protects surface waters from pollution.

Regulates discharge of pollutants and sets water quality standards.

What are ecosystem services?

Benefits humans get from nature, such as clean water, air, flood control, pollination, and recreation.

How did acid rain affect water quality, fish, and trees?

Low ph → harms aquatic life, damages trees and decreases water quality

What is acid rain and how did the acid rain problem improve?

Rain with LOW PH LEVELS: clean air act amendments: cap and trade programs to reduce power plant emissions

Geologic definition of soil

earth material that is altered to support plant life

Engineering definition of soils

earth material that can be removed without blasting

What are the different soil horizons, where is organic matter and accumulation?

O - topsoil, zone of leaching

A - (organic matter) - topsoil, zone of leaching

E -  zone of leaching

B - zone of accumulation

C - substrate

Why do soils have color and what do changes in color indicate about drainage?

Dark brown/black = high organic matter.

Red/yellow = well-drained, oxidized iron.

Gray/blue = poor drainage, waterlogged, reduced iron.

How do soils become fertile?

The capacity of soils to support the nutrients (nitrogen, phosphorus, potassium) needed for plant growth

→ phosphorus cycle

1. New substrate layer

2. Weathering (100s to 1000s of years)

3. Degrading (necessary materials are depleted) (variable)

What is hydraulic conductivity?

Measure of how easily water moves through soil. Sand high, clay low

When did sediment yields peak in the Piedmont region and what caused it?

1960 → human activities influence surface change

How does agricultural soil erosion influence the amount and fertility of soil?

Affects topsoil - lowers fertility and crop yields. Contour plowing, terrace architecture, planting more than u can crop

Where is soil erosion a problem and where/how does it occur?

Affects soil depth and profile development - Measured by volume, mass, or weight of solid removed within a given time

How does urbanization impact soil erosion?

• conversion of forested or agricultural land

• Dramatic runoff during construction - soil scraped off and lost desiccation (aka demoisturized)