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ENVI 485 2/6/07. Introduction to Environmental Geology (cont.) Land use planning Introduction to soils. Population growth Sustainability The earth system Uniformitarianism Hazardous earth processes. Geology as a basic environmental science. Fundamental Concepts of Environmental Geology.
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ENVI 485 2/6/07 • Introduction to Environmental Geology (cont.) • Land use planning • Introduction to soils
Population growth Sustainability The earth system Uniformitarianism Hazardous earth processes Geology as a basic environmental science Fundamental Concepts of Environmental Geology
Fundamental Concepts-Geology as a basic environmental science • Geology is a factor in every person’s life: • “Civilization exists by geological consent…subject to change without notice”--Will Durant
Fundamental Concepts-Geology as a basic environmental science • Branches of Environmental Geology: • Geomorphology (Geologic Landforms and Processes) • Hydrogeology (Water and soil / rock interactions) • Pedology (Soils) • Economic geology • Engineering geology • Classical geology
Fundamental Concepts-Geology as a basic environmental science • Environmental problems are interdisciplinary • Physical Geography, geologic processes, hydrology, rock types, soil types, climate • Biological • Plants, animals, biologic conditions, spatial analysis of biologic information • Human interest/use Land use, economics, aesthetics, environmental law, hazards, historical/archaeological value
Environmental Geology and Land-Use Planning • There is a limited supply of land • We strive to plan so that suitable land is available for specific uses for this generation and those that follow • Comprehensive plan – designed for long-range local development based on an environmental inventory of resources and hazards
Landscape Evaluation • Environmental geologists provide geologic information and analysis to assist in planning, design, and construction • Former and present land use • Physical and chemical properties of earth materials • Pollutants • Engineering Properties of soil and rock • Natural hazards • Groundwater characteristics
Site Selection • Cost-Benefits Analysis – Assumes all relevant costs and benefits can be determined • Examples: Building a shopping mall in a flood zone; Drilling oil wells in National Parks? • Physiographic Determination-applying ecological principals to planning • Considers physical, social, and aesthetic data • Let natural characteristics determine the choice of a site
Environmental Impact Analysis • 1969- National Environmental Policy Act (NEPA) • All major federal actions which could affect the quality of the human environment must be preceded by an evaluation of the project and the potential impact to the environment • Environmental Impact Statements (EIS) • Discussion of the environmental consequences of the proposed project and of the alternatives • State Environmental Impact Legislation • State Environmental Policy Acts (SEPAs) • California Environmental Quality Act (CEQA)
What do Environmental Geologists do? Mostly Site Assessments (ESAs) and Brownfields Studies
What are “Brownfields”? • brownfield site • “real property, the expansion, redevelopment, or reuse of which may be complicated by the presence or potential presence of a hazardous substance, pollutant, or contaminant.”
Conventional borings/excavation groundwater monitoring wells decontamination/plugging/abandonment/waste disposal crude field-screening off-site analysis Accelerated geophysical surveys direct-push probes field labs/test kits off-site analytical confirmation electronic data archiving/interpretation Sampling/Analysis –Sampling Methods
What are ESAs? • Identify/evaluate: • environmental concerns • Magnitude and extent of contamination • Cleanup goals • Remediation options • Future land use
Phase I ESA • Identify potential environmental concerns • All Appropriate Inquiry • Records review • Site reconnaissance • Interviews • Report
Evaluates potential concerns from Phase I Tailored to site-specific needs Limited sampling/analysis Confirm/rule out concerns Expanded sampling/analysis Amount and extent of contamination Recommended cleanup goals/options Phase II ESA Increasing Costs
Phase III ESA • Corrective actions for environmental concerns
Land Uses Contaminants & Related Risk What are ESAs? – Summary Focus on: Site Improvements Past, Present & Future
Sampling/Analysis –Sampling Methods • Conventional drilling/sampling technology
Sampling/Analysis –Sampling Methods • Screening/field-based methods - Direct-push methods
Sampling/Analysis –Sampling Methods • Geophysical Methods Ground-Penetrating Radar Electromagnetic Conductivity & Magnetic Surveys
Soils • Crucial to land use planning • Waste disposal • Evaluation of natural hazards • Flooding • Landslides • Earthquakes • Evaluation building construction
Soils as a natural resource “The thin layer of soil covering the Earth’s surface represents the difference between survival and extinction of most terrestrial life”
Soil: Definition • Soil Scientist: • Solid earth material that can support rooted plant life • Engineer / Geologist: • Earth material that can be removed without blasting (any earth material that is ripable)
Components of soil:1. Minerals • inorganic materials derived from weathering rocks • extremely variable in size. • Provide nutrients to plants • Basis for soil classification
Components of soil:2. Air • Pore spaces filled with air or water comprise 1/2 the volume. • The amount and composition of air in a soil are determined by the water content of the soil. • Metabolic activity of roots, microbes and fauna change the composition of soil air. (Carbon dioxide greater than atmosphere).
Components of soil: 3. Water • Water is the major transport agent in soil • Within the soil • To groundwater • participates in geochemical cycles • weathering geological substrates • leaching materials to groundwater • moving ions and particles through the soil profile. • Organisms alter the suite of solutes in percolating water
Components of soil:4. Organic Material • includes: • living organisms (soil biomass) • remains of organisms • decomposed organic compounds
What is soil? • Open, dynamic, natural bodies in the landscape. • exchange water and air with the atmosphere, and ions and minerals with the lithosphere • Plants introduce reduced carbon to support a heterotropic biomass • Decomposition of these substrates results in the cycling of nutrients
Controls on soil formation • Climate • Topography • Parent material • Time • Organic Processes
Soils • Soil forming process produce distinctive layers (horizons) defined by the processes that form them • Leaching • Oxidation • Accumulation of minerals