180 likes | 286 Views
Case History: Surface Water Development. Aral Sea Location – central Asia Tourism, Commercial fishing 1918: Soviet instituted water diversion for agriculture-Uzbek cotton Results: 20-m water level drop, climate modification, desertification, health issues, increased salinity.
E N D
Case History: Surface Water Development Aral Sea • Location – central Asia • Tourism, Commercial fishing • 1918: Soviet instituted water diversion for agriculture-Uzbek cotton • Results: 20-m water level drop, climate modification, desertification, health issues, increased salinity GLY 2030C
Philosophy and Fundamental Concepts • Land Ethic – responsibility to more than just humans & society • Species vs. individual • Humanity is an integral part of the environment • A moral obligation to those who follow • The Land Ethic and American Experience • Aldo Leopold: Sand County Almanac • Set the stage for modern conservationist movement GLY 2030C
Philosophy and Fundamental Concepts • Land Ethic – American Experience • Pilgrims • Technology (ax, gun, wheel) • Organizational skills • Concept of land ownership • Myth of Superabundance – inexhaustible resources • Hydraulic Mining • Seeds of Conservation • John Wesley Powell GLY 2030C
Philosophy and Fundamental Concepts Deforestation and soil erosion Mining Surface and groundwater development GLY 2030C
Philosophy and Fundamental Concepts • Concept 1: • Population Growth • #1 environmental “problem” • From 1830 to 1930, population doubled to 2 billion • From 1930 to 1970, doubled again to 4 billion • 2000 estimate is about 6 billion
Philosophy and Fundamental Concepts • Concept 1: • Population Growth in Florida • Florida in the 1980s and 1990s, averaged ~2%/year (same rate as a developing country)
Philosophy and Fundamental Concepts • Constant Doubling time • Exponential growth curve (J-shaped) • Blackboard example of equation: • N=Noekt GLY 2030C
Philosophy and Fundamental Concepts • Concept 2: Sustainability • Resources • Food • Leads to idea of a Global Economy • Populations in harmony with ecosystem • Energy policy (pollution-free or acceptable risk) • Use plan for renewable resources • Use plan and reservation of non-renewable resources • Sustainable legal, political, and legal systems • To achieve sustainable global economy: • Effective population control • Restructured energy program • Global economic planning • Social, legal, political, and educational systems to support global environment GLY 2030C
Philosophy and Fundamental Concepts Concept 3: Systems Hydrosphere Biosphere Atmosphere Lithosphere GLY 2030C
Philosophy and Fundamental Concepts • Open system- energy exchanges • Closed system- material is continuously recycled; • Earth is a coalition of closed systems • Feedback-output becomes input; causes change (e.g. neighbor and loud music) • Negative- outcome moderates/decreases process • (river model) • Positive -outcome of change amplifies the initiating event • (Off-road vehicles) GLY 2030C
Philosophy and Fundamental Concepts • Growth rates • Measured as a percentage • N=N0ekt or t=(1/k)ln (N/N0) • Doubling time • 70 divided by rate of change • Predicting Change in Systems • Input-Output analysis • Blackboard Example of Avg. residence time GLY 2030C
Philosophy and Fundamental Concepts GLY 2030C
Philosophy and Fundamental Concepts GLY 2030C
Philosophy and Fundamental Concepts • Complex systems and Earth System Science • Natural systems are seldom at equilibrium • Systems are often complex with thresholds and disturbance (chaos) • Earth system science: studying entire Earth • Gaia Hypothesis • James Hutton (Father of Geology) believed the Earth is a super organism • James Lovelock and his ideas stimulated interdisciplinary studies on how the planet works GLY 2030C
Philosophy and Fundamental Concepts • Concept 4: Limitation of Resources • Earth • Only place to live that is accessible • Resources are limited; some renewable, some not • Natural resources • Cornucopian concept (we’ll find a way) • Resource crisis • Medical technology and overpopulation • Economies based on waste and obsolescence • Finite accessible mineral base • Irreversible environmental damage from all the above • Concept 5: Uniformitarianism (James Hutton) • The present is the key to the past • Uniformity of Process, not magnitude and frequency • EG-The present is the key to the future GLY 2030C
Philosophy and Fundamental Concepts • Concept 6: Hazardous Earth Processes • There have always been geohazards • Can be recognized and avoided where possible • Minimize threat to human life and property • Concept 7: Geology: Basic Environmental Science • Fundamental component of everyone’s environment • environment requires an understanding: • Engineering geology • Economic geology • Hydrology • Geomorphology • Sedimentology GLY 2030C
Philosophy and Fundamental Concepts • Concept 8: Our Obligation to the Future • Early Hominids didn’t influence the Earth until the discovery and use of fire • Development of agriculture (5,000 B.C.) spurred population growth driving increased land clearing (positive feedback) • Human activity (45 GT/yr) – cf. tectonic activity (34 GT/yr), river transport (24 GT/yr) • Ducktown, Tennessee (1840s-1850s, copper rush) - Beginning of environmental law