Misuse of wetlands lecture 9

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Enger & Smith

Environmental ScienceA Study of Interrelationships

Thirteenth Edition

Chapter 12

Land-Use Planning

Land-Use Planning

12.1 The Need for Planning Once converted to intensive human use,

• unavailable for other uses

Present land use in the United States:• 52% - Crops and livestock• 44% - Forests and natural areas• 4% - Intensive human use

12.2 Historical Forces That Shaped Land Use

North America rural • industrial growth began in last third of the 1800s.

Cities grew because of:• Industrial Revolution

– farms to industrial jobs in cities

• European immigrants– Congregated in cities

– jobs were available

Migration from the Central City to the Suburbs

As cities grew, • certain sections within city deteriorated• Pollution and crowding

– made cities undesirable

In the early 1900s, • people moved out of cities • 1950 - 60% urban population lived in central cities.• 1990 - 30% urban population lived in central cities.


Rural-to-urban population shift


Rural-to-urban population shift


Urban sprawl • Spread low-density, auto-dependent development• On rural land outside compact urban centers (suburban)• Characteristics:

– Excessive land consumption.– Lack of choice in ways to travel.– Fragmented open space (scattered appearance).– Lack of choice in housing – Segregation of commercial and housing– Lack of public spaces

.

12.4 Problems Associated with Unplanned Growth

Death of the Central City• less than 10% work in the central city.

Loss of Sense of Community• feeling isolated

Higher Infrastructure Costs• Extension of municipal services more costly


Transportation• As cities grew,

– little thought given to transportation corridors.

– constant road building.

– Large Metro– 40 hours/year stuck in

traffic


Loss of Open Space and Farmland


Air Pollution• traffic increases, so

does air pollution.

• public transportation difficult

with highly dispersed population.

Water Pollution– high runoff and potential

flooding.


Floodplain (low areas near rivers)

• flooding

• Many cities on floodplains – originally established along waterways.

– Flat land is attractive to developers – Flood control structures– Forces water downstream

– floodplain zoning ordinances– Restrict building in floodplain


Flooding in Floodplain


Wetlands (like estuaries)

• areas periodically covered with water.

• Many have been drained, filled, or used as landfills.– U.S. lost 53% of wetlands since the European immigration

– Reproductive phase of many organisms.

– Provide sediment filtration.

12.5 Land-Use Planning Principles

Land-use planning • process of evaluating:• needs and wants of a population, • the land characteristics and value, • various alternative solutions to land uses before

changes are made.

• A basic rule should be to make as few changes as possible.

12.7 Special Urban Planning Issues

Urban Transportation Planning• Four goals:

– Conserve energy and land resources.

– Provide efficient and inexpensive transportation,

– Provide efficient transportation to suburban.

– Reduce urban pollution.

12.7 Special Urban Planning Issues Urban open space; recreation planning

• nature centers

12.7 Special Urban Planning Issues Smart growth

• Developing “livable” cities and towns.• Quality of environment directly affects quality of life.

Principles:• Mix land uses.• compact building designs (multistory)

• Walkable neighborhoods• Preserve open space• Variety of transportation choices.

12.7 Special Urban Planning Issues

Smart growth • building of “green

buildings.”

• using recycled materials,

• ensuring better ventilation in buildings,

• reducing water and energy use


Enger & Smith


Thirteenth Edition

Chapter 14

Agricultural Methods and Pest Management

14.1 The Development of Agriculture Development of

agriculture• manipulating

environment to produce food

• increase in human population.

Mechanized monoculture agriculture• manufacture pesticides

and fertilizer

Problems with mechanized monoculture agriculture:

• Increases soil erosion.• Little genetic differentiation

– increased pesticide use.• No crop rotation depletes soil nutrients,

– increasing fertilizer use.

14.1 The Development of Agriculture

14.3 Agricultural Chemical Use A pesticide

• any chemical used to kill or control populations of unwanted fungi, plants, or animals (pests).

Based on the organisms they control.• Insecticides -- insect populations.• Fungicides---fungal pests.• Rodenticides---mice and rats.• Herbicides --plant pests.• Biocides

14.3 Agricultural Chemical Use

The discovery of chemicals that could kill insects • major advance in the control of disease and the

protection of crops.• Mosquitoes

In 1942, DDT became the first synthetic organic insecticide produced.


Organophosphates and carbamates • short-lived pesticides • do not persist in the environment.

Affect the nerve cells of humans and other vertebrates

Must use special equipment receive special training in safe application

practices.


Herbicides • control unwanted plants • heavily used in genetically modified crops.• 60% of all pesticides used in U.S. • Weeds compete with crops for soil nutrients• Traditional weed control methods

– expensive in terms of time and energy.


Fungicides • protect agricultural crops from spoilage• prevent spread of disease • protect seeds from rotting in the ground

– Methyl mercury is extremely toxic to humans.

Rodenticides prevent poisoning non-target organisms Especially humans

14.4 Problems with Pesticide Use

Persistent pesticides (DDT)

• attached to small soil particles• easily moved by wind or water.• distributed throughout the world from local

applications.

• Discovered in polar ice • present in the bodies of animals, including humans,

throughout the world.


Bioaccumulation • process of accumulating higher and higher amounts of

material within an organism’s body.– build up in fat tissues.

Biomagnification • process of acquiring increasing levels of a substance in

bodies of higher trophic-level organisms.– DDT, mercury, and PCBs

The biomagnification of DDT


Pesticide resistance • Insecticides only kill susceptible individuals.

• Surviving individuals – characteristics allowed them to tolerate the pesticide.

– Survivors pass on genetic characteristics for tolerance.

– Subsequent pesticide applications less effective.


Most pesticides are not species-specific • kill beneficial species as well as pest species.• Many kill predator and parasitic insects

– normally control pest insects.

• Insecticides may change the population structure – species not previously a problem may become a serious

pest.


Short-term and long-term health effects

Acute poisoning during application WHO

• 1 million and 5 million acute pesticide poisonings a year• resulting in 20,000 deaths.

• Farmers exposed to pesticides over many years – higher levels of certain kinds of cancers


Enger & Smith


Thirteenth Edition

Chapter 15

Water Management

15.5 Kinds of Water Use

Urban domestic water uses

15.6 Kinds and Sources of Water Pollution

Disease-causing organisms • pollution problem in most of the world.

Source of these organisms• Untreated or inadequately treated human or

domesticated animal waste

• Sewage treatment and drinking-water treatment plants

– reduce this public health problem.


Point source • source of pollution readily located… identified.• Municipal and industrial waste (discharge pipes).

Nonpoint sources • Difficult to identify and control.• Pollutants from agricultural land • Pollutants urban paved surfaces• Acid rain


Protect surface and ground waters from nonpoint pollution:• Use less toxic or nontoxic alternatives to home

chemicals.

• Buy chemicals only in the amount you need, apply as directed.

• Unwanted household chemicals to hazardous waste collection centers.

– not pour them down the drain.


Municipal Water Pollution• Waste from homes

– organic matter from garbage, food preparation, cleaning of clothes and dishes, and human waste.

– Fecal coliform bacteria

Agricultural activities are the primary cause of water pollution.• Excessive fertilizer• Runoff from animal feedlots carries nutrients, organic

matter, and bacteria.

Wastewater Treatment


Factories and industrial complexes • frequently dispose of waste in municipal sewage

systems.• may require special wastewater treatment.

Mining – Industrial water pollution.• Chemical run-off is released into streams.• Water draining from mines is highly acidic.


Enger & Smith


Thirteenth Edition

Chapter 16

Air Quality Issues

16.3 Categories of Air Pollutants

Primary air pollutants • released directly into the atmosphere • sufficient quantities to pose a health risk.

They are:• Carbon monoxide• Volatile organic compounds (hydrocarbons)• Particulate matter• Sulfur dioxide• Oxides of nitrogen


Carbon monoxide • organic materials are burned with insufficient oxygen.• The single largest source is the automobile.

– Remainder from burning, i.e., power plants, leaves, etc.

• Binds to hemoglobin in blood – makes the hemoglobin less able to carry oxygen.

• It is most dangerous in enclosed spaces


Sulfur dioxide (SO2) • compound of sulfur and oxygen produced when sulfur-

containing fossil fuels are burned.

• Burning coal releases SO2.

• coal-burning power plants.

– U.S. levels of SO2 decreased 56% between 1990 and 2007.


Oxides of nitrogen (NOx) are formed when fossil fuels are burned. • Nitrogen monoxide (NO) and nitrogen dioxide (NO2)

most common.

• Burning fossil fuels in internal combustion engines– Primary source of nitrogen oxides.– Automobiles produce 38%– Non-road motorized equipment produces 21%

16.7 Global Warming and Climate Change

Climatic records indicate over the past 160,000 years • close correlation between greenhouse gas concentration

and global temperatures.

• Climate change report (2007)– Average temperature on Earth has increased 0.56 to 0.92°C

(1.0-1.7° F) in the past 100 years

– Sea level is rising about 1.8 mm/yr or 18 cm in 100 years

Changes in Average Global Temp


.A strong correlation exists between temperature increase and amount of greenhouse gases in the atmosphere.• Human activity increases greenhouse gases in

atmosphere.– Greenhouse gases increased 70% btw 1970 and 2004


Greenhouse effect:• Greenhouse gases allow sunlight to penetrate the

atmosphere.• Sunlight is absorbed by Earth’s surface.• It is reradiated as infrared energy (heat).• The heat is absorbed by gases in the atmosphere.


Greenhouse effect


Carbon dioxide--most abundant of the greenhouse gases.• Deforestation contributes to the amount of carbon

dioxide in the atmosphere.

Methane • comes from biological sources and • from some fossil-fuel burning activities.

Nitrous oxide • from fossil fuels and fertilizers.

Chlorofluorocarbons from refrigerants, and propellants.


Small increase in the average temperature may seem trivial• set in motion changes that could significantly alter the

climate

• Affect:– hydrologic cycle

– sea level,

– human health,

– survival and distribution of organisms

– use of natural resources by people.

Misuse of wetlands lecture 9

Education

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