Earth Science Notes Human Impacts On Land Human
- Slides: 40
Earth Science Notes Human Impacts On Land
Human Impacts BIG IDEA Protecting the human interests of health, safety and resource management depends on an understanding of natural hazards and human impacts on Earth systems.
Human Impacts Human Activities that Impact Land • Population Growth • Farming • Mining • Land Development • Waste Disposal
Population Growth • Population growth = death rate and the birthrate. – However, when the death rate is high, the birthrate is normally also high. • Population growth is directly related to: current population, birth rate, death rate. – Growth rate = Birth Rate - Death Rate • 1. 3% = 2. 2% - 0. 9% (today) • Of these the Birth Rate is the most important contributor, specifically the Fertility Rate (#children/woman) – Why? Because death rates have stabilized. . .
Population Growth
Population Growth Populations of countries go through 4 stages • Preindustrial Stage – little population growth because harsh social conditions lead to both high death and high birth rates. • Transitional Stage – when industrialization begins and health care improves, resulting in lowered death rates, but birth rates remain high. – Most of the developing world here. • Industrial Stage – when the birth rate drops due to modernization (and its accompanying social changes). – Many developed countries and a few developing countries here. • Postindustrial Stage I – recognized by further reductions in birth rates, approaching or even below zero population growth. Approximately 13% of the world population (mostly European countries) is in this stage.
Population Growth
Population Growth
Population Growth Notice the difference in the age distribution is impacted by the countries’ stage in development
Population Growth Carrying Capacity (K) How many people can the Earth support? • Physical carrying capacity = “packing density”, limited only by space and resources – Cultural carrying capacity is always less – Still there is a large difference of opinion regarding how many people the earth can support. • Accepted range for K is 10 -20 billion people
Population Growth • • Factors affecting carrying capacity Food availability Water Environmental conditions Space.
Population Growth • UN projects the WP will reach 28 billion by 2150 (about 4 X today's population) • Some scientists project the Earth’s population will stabilized around 2030. – Falling birthrates due to developing nations – Possible increase in death rate • Current death rates is 9 d/1000 – This puts average of death at 111 in the future • Based on average of death worldwide at 75 years, this puts the death rate a 13. 3 d/1000
Farming Impacts Fertilizers Positive Impacts: • Increases variety, abundances of Food • Allows food to be grown cheaper Negative Impacts: • Can increase soil acidity (apply lime) • Can runoff into lakes and streams – Kill aquatic life, overgrown lakes
Farming Impacts Grazing of Livestock • Soil degradation – Increases runoff due to soil compaction • Soil/Water contamination (e. coli) • Soil Erosion • Reduces plant density – Factor leading to desertification
Farming Impacts
Mining Impacts Mining of Minerals Creates Acidic Mine Drainage (AMD) • When metal ores are mined metals in rock can oxidize and release H+ (acid ions) into streams. • Nationwide, over 12, 000 miles of rivers and streams and over 180, 000 acres of lakes and reservoirs are adversely affected by contaminated water draining from abandoned mines. • River and Groundwater are contaminated • AMD has adverse affects on wildlife
Mining Impacts Acid Mine Drainage
Mining Impacts Mining of Minerals Causes Erosion and Deposition • The mining process releases large quantities of sediment that are transported by water erosion. • The sediment eventually drops out of the water and deposition occurs at some point downstream.
Mining Impacts Erosion and Deposition
Mining Impacts Mining of Minerals Habitat Modification • Mining adversely affects aquatic habitats (i. e. lakes, ponds, streams, rivers), terrestrial habitats (i. e. deserts, grasslands, forests) • Change topography of the land • Change waterways and draining
Mining Impacts Mining of Minerals
Impacts of Land Development • Increased runoff and flooding • Less flow during dry seasons • Increased erosion
Impacts of Land Development Reduced Farmland • It is estimated that 1. 5 million acres of productive farmland are lost every year to urbanization. • How can we feed an increasing population with a decrease in farmland?
Impacts of Land Development Deforestation • The clearing of forest for agriculture, logging, or development • Deforestation creates loss of habitat – Tropical forests contain the greatest diversity of wildlife on the planet – May lead to the extinction of species • Deforestation can affect regional climates – Fewer trees = less evaporation/transpiration = less rain = dryer climate.
Impacts of Land Development
Impacts of Land Development
Impacts of Land Development
Impacts of Waste Disposal Hazardous Waste • Wastes that can catch fire, cause cancer, or are generally poisonous. • HW needs to be disposed of differently than our everyday garbage
Impacts of Waste Disposal A waste is hazardous if it exhibits one or more of the following characteristics: • IGNITABILITY — catch fire • CORROSIVITY — acidic, eat through metals • REACTIVITY — unstable, may explode. • TOXICITY — harmful or fatal when ingested or absorbed
Impacts of Waste Disposal Dealing with Waste Sanitary Landfills • Where everyday garbage is deposited • Designed to prevent liquid waste from draining into the soil. – Lined with clay or plastic liner, have fluid collection system, and air vents.
Impacts of Waste Disposal Dealing with Waste Phytoremediation • Use of plants in the removal of contaminants from contaminated soil, water, sediments, and air. • Cheaper / more aesthetically pleasing (pretty)
Phytoremediation Examples Pollutant Medium plant(s) Petroleum & Hydrocarbons Soil & Groundwat er Alfalfa, poplar, juniper, fescue Heavy Metals Soil Hybrid poplar, grasses Radionuclides Groundwater Sunflowers Radionuclides Soil Indian mustard, cabbage Expolsives waste Groundwater Duckweed, parrotfeather Nitrates Groundwater Hybrid poplar
Impacts of Waste Disposal Dealing with Waste Enzymes • Substances that speed up chemical reactions. • Ennzymes breaking down of pollutants in simpler, more harmless substances
Summary Be able to… • Describe factors that affect human population growth • Define carrying capacity (K) • Explain how each human activity described impacts the environment • Describe methods of limiting human impacts
- My favorite subject is english and math
- An area of land largely enclosed by higher land
- Grassland landforms
- Lowest place on earth on land
- Percentage of land on earth
- Water distribution on earth
- Land use planning lecture notes
- Land use planning '' lecture notes
- Land use planning '' lecture notes
- Which of earth's layers is the thickest
- Physical properties of inner core
- Wisc
- Types of wind
- Positive impacts of materials technology
- Material technology positive and negative impacts
- Positive effects of information technology
- Ecotourism advantages
- Educate
- Long term impacts of the industrial revolution
- Impact of gaa on irish life
- Haitian revolution causes
- Negative impacts of materials technology
- Negative social impacts of tourism
- Positive impacts of tourism in glasgow
- Meaning of ict
- Demand-pull inflation occurs when
- Long term impacts of the industrial revolution
- Long term impacts of the industrial revolution
- Impact of tidal energy on environment
- What are the environmental impacts of fossil fuels
- Commercialisation triangle
- Negative effects of war
- Social impact of ict
- Impact of logging on agriculture production
- Social effects of natural disasters
- How is death personified in the pardoner's tale
- What are the social impacts of information technology
- Nsf intellectual merit
- Urban hearths
- Socio-cultural impacts
- Write an essay on "what are the impacts of deforestation?"