Final Exam - Water and the Environment, Kent State, Dr. Singh

Why does freshwater flow towards the ocean?

As a result of the regional water table gradient.

What are causes of seawater intrusion?

-over pumping of groundwater.
-sea level rise.
-land subsidence.
-diversion of surface water.

How does seawater intrusion occur because of over pumping groundwater?

Upconing of the seawater below the freshwater lens; a cone of depression forms in the fresh groundwater, resulting in seawater being pulled up in its place.

What is an estuary?

Where a sediment-starved river meets the ocean.
It has a greater inflow of freshwater than seawater.

List the characteristics of estuaries.

-They are very nutrient rich, supporting productivity and biodiversity.
-Fast moving rivers carry nutrient-rich particles.
-Streams slow down and sediment is dropped out, making it great for plants to grow.

What are lagoons?

Estuaries that are parallel to the coast.

What are coast plain estuaries?

Rising sea levels fill in an empty river channel. Characterized by erosion.

What are tectonic estuaries?

Tectonic activity creates a fault and it is filled in by water.

What is a fjord?

flooded coastal glacial valley.

How do salt marshes form?

In estuaries that are protected from high energy waves.

What are examples of estuaries?

Lagoons, bays, harbors, sounds, and inlets.

What kinds of estuaries form behind barrier islands and beaches?

Swamps and lagoons.

What are some examples of ecological services provided to us by marine systems?

-Climate moderation
-Nutrient cycling
-Reduced storm impact
-Wastewater treatment and dilution

What are some examples of economic services provided to us by marine systems?

-Food
-Minerals
-Pharmaceuticals
-Harbors and transportation routes

What 2 places do nutrients that enter marine systems come from?

-Surface rivers
-Submarine groundwater discharge

What does SGD stand for?

Submarine groundwater discharge

What is biological production in coastal environments based on?

Nutrients introduced by submarine groundwater discharge.

What does brackish mean?

Water is a mixture of both fresh and salty water.

How does the salt gradient change in an estuary?

-near river input= 0-5 ppt
-middle of the estuary= 5-25 ppt
-at the ocean= >25 ppt

What are the important functions of estuaries for living things?

-Habitat
-Nursery
-Fisheries
-Recreation

What are the important water functions of estuaries?

-Flood control
-Buffers land from hurricanes; stops the storm surge
-Water purification

How did wetland loss affect Hurricane Katrina?

The storm wasn't slowed, the loss of the wetlands led to there being nothing to buffer to storm.

What are salt marshes?

A low area that is subject to regular, gentle tides. It is dominated by grasses (no trees).

What are mangrove swamps?

Coastal wetlands located in tropical and subtropical zones. Dominated by salt-tolerant trees and shrubs.

What 2 things do coral reefs require to live?

1. Warm temperatures
2. Sunlight

Where on Earth are coral reefs found?

Between 30 degrees North and South.

What is the water table?

It is the upper portion of an aquifer that is 100% saturated; no air.

What is the potentiometic surface of a confined aquifer?

The height to which water pressure would raise the water.

What is porosity?

The volume of pore spaces available to store water in sedimentary rock.

How do you calculate for porosity?

(Volume of pores)/(Total volume of the rock)

What can water table maps indicate?

Surface water-ground water interactions

What does head gradient mean?

The slope of the water table

In what direction does water flow from?

From high to low pressure

What is hydraulic conductivity?

The ease of which a fluid can flow through an aquifer's pore spaces.

In a cone of depression, what factors control its zone of influence?

-Permeability
-Pumping rate
-Number of wells
-Aquifer type
-Distance to bedrock and rivers

Where do sinkholes form?

In areas with abundant water and has a limestone or gypsum bedrock.

What are springs?

Where the water table intersects with the land surface and and water flows onto land.

What benefits come from natural springs?

-Regulate temperature year round.
-Nutrient supply from groundwater.
-Low oxygen supports anaerobic reactions in wetlands.
-Habitats for endangered species.

What is a geyser?

Hot spring water that erupts from the ground. The water's heat is due to the geothermal gradient.

What are uses of geothermal hot springs?

-Generate electricity
-Nonelectric space heating
-Manufacturing

What causes groundwater and lake levels to change seasonally?

Seasonal changes in rainfall and precipitation.

Under what conditions does salt accumulate in nature?

When evaporation exceeds precipitation.

True or false? Pollution doesn't equal contamination, but contamination does equal pollution?

False (it's vice versa)

What are the biggest contamination problems of today's society?

Air pollution and climate change.

What are the biggest water contamination problems of today?

-Sewage and wastewater
-Fossil fuel pollution
-Industrial and nuclear waste
-Oil spills

How much of the world's wastewater flows back into the environment without treatment?

>80%

The majority of contaminants are _______ (visible or invisible).
What are examples?

Invisible.
Examples are gases and aqueous-phase contaminants.

What is point source contamination?

The contamination source is located at a specific place.

What is non point source contamination?

The source of contamination is not from one place, it's spread out and difficult to pinpoint.

How much waste are electric plants allowed to dump according to the EPA?

1.4 billion lbs

What is water quality measured by? (2 things)

DOC and BOD

What does BOD stand for?

biochemical oxygen demand

What does BOD mean?

The amount of oxygen required by aerobic microorganisms to decompose the organic matter in a sample of water.

What is a dead zone?

Caused by contamination; there is too low of a dissolved oxygen supply in water to mean the biochemical oxygen demand, and life begins to die.

How much damage does coastal pollution cost?

$30,000/minute

What is the cause of the large oxygen-depleted zone in the Gulf of Mexico?

Algal blooms

What is the largest estuary in the USA?

Chesapeake Bay

What problem is the Chesapeake Bay facing today?

It's is a pollution sink; it is oxygen depleted.

What types of metals are commonly observed from abandoned mine drainage?

Sulfide metals

When does acid mine drainage occur?

When calcite or dolomite is present in metal ore.

What are remediations and treatments for AMD?

-Dilution
-Filtering
-Constructed wetlands
-Alkaline beds
-Limestone channels