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93 Cards in this Set
- Front
- Back
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Who was Gifford Pinchot, what was the resource conservation ethic and what did sustainability mean in this respect?
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1898 was named head of the Forestry Division in the Department of Agriculture
-He began with a staff of 12persons, 6 for clerical and 6 for scientific work. -Within 7 years his staff had increased to 700. -Forestry and forest management had joined the curriculum of many universities. |
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• What is the Stewardship Land Ethic?
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o A science of conservation was needed that incorporated ecological and ecosystem concepts rather than just maximum yield and economics
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who was Aldo Leopold
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- 1887-1948, founder of the Wilderness Society, graduated from Yale in Forestry and served in the Forest Service for many years.
-He taught “interrelation of species on a piece of land needs to be stressed rather than the welfare of one or two” -Using his ideas, his family actually restored a worn-out farm on the prairie in Wisconsin. -He wrote one of the most respected books on conservation of the natural environment ever written: A Sand County Almanac |
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• Early timber protection in the U.S. was for what reason?
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Military purposes
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• When were the first national parks created? What were the first 3?
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o Sequoia, Yosemite, and General Grant National Parks were created in 1890
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• 1891 – what was the beginning of the National Forest System?
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o In 1891, the beginning of the National Forest System when the President was given the power to set aside forest reserves from the public domain.
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• 1911 – what was the Weeks Law? Why was it important?
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o In 1911, the Weeks Law gave the president authority to purchase forest land for river watershed protection.
-This law linked forest, water and soil conservation. -It also authorized forest fire prevention and control. |
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• Why was Rachel Carson’s book important?
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o Rachel Carson’s book, Silent Spring, on environmental pesticide pollution, especially DDT, was published in 1962.
-It was an immensely popular book and woke scientists up to the damage pesticides were doing to our environment. |
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• What were the four purposes of the NEPA – 1970?
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o First comprehensive statement of U.S. environmental policy
- enhance quality of renewable natural resources -preserve natural, cultural and historical resources - sustain environmental resources for the future - protect Americans from environmental pollution |
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• 1970 - What does the CEQA require and protect?
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• requires an analysis of the Environmental impact of a project
• biological resources, cultural resources, air and water pollution, and traffic impacts must be considered • steps to avoid or mitigate impacts must be considered |
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• What is the goal of the Clean Water Act – 1972
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o Goal: Make U.S. rivers, lakes, and shores safe for fishing and swimming
o Focus: point source industrial pollution – mercury, arsenic, PCB, and DDT were early targets o Passed in response to worsening issues of water pollution; regulation of point-source emissions |
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• What government body regulates the Clean Water Act?
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o Section 404: Army Corps of Engineers given the responsibility to regulate dredging and filling of “navigable waters” of the United States
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• 1973 – Endangered Species Act protects organisms and habitats in which two categories?
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o plants and invertabrates
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• 1984 – CA endangered Species Act… how is it different from Federal ESA?
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o Three categories of protection
-Endangered -Threatened -Rare o Does not protect invertebrates o Public process of adding species; thus many more species are included than under Federal ESA |
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• Development and land use should avoid mismatched design schemes – why?
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o Responsive planning
o Avoid mismatched design schemes Environment and land use should be compatible o Sustainable landscapes should be the goal |
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• What is the definition of Landscape Planning?
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o Landscape planning – the decision making, technical, and design processes associated with the determination of land uses and the utilization of terrestrial resources
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• What is the definition of Environmentalism?
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o Environmentalism –Advocacy for or work toward protecting the natural environment from destruction or pollution.
o A philosophy o Some call it the “destructive religion” of environmentalism. |
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• What is the definition of Environmental Planning
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o Environmental planning –planning and management activities in which environmental rather than other factors are the central considerations
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• What is Environmental Analysis and why do we use it?
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o Environment review is necessary for all projects that require a formal decision by government and regulatory agencies regarding a project's potential to impact the environment.
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What is site scale? What is regional scale?
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- Sites are local parcels with a simple ownership or stewardship arrangement – 1 to 100s acres.
o Sites are the building blocks of communities. - Regional scale – many important environmental problems exist at the regional scale – i.e. groundwater withdrawal and acid rain, but are much harder for planners to deal with |
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• Why aren’t natural systems like technological systems?
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o Natural systems are not as fast, dependable and tireless as technological systems
o Nor are they simple and easily understood |
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• What is wrong with “quick fixes” using technology? What is an example of a quick fix?
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o Technology has grown exponentially
o We are used to quickly solving our problems using new technology o We look for “quick fixes”, like fixing runoff systems by channeling runoff down straight, deep, extended canals |
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• Give an example of land use decisions that are a mismatch with the landscape.
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o Initially poor land use decisions (building a nuclear reactor on a large fault)
o Environmental change after a project has been built (erosion of coast from sea level rise) o Social change (roads for horse-drawn carriages to cars and buses) o Poor planning and design – old student union o Violations of human values, like the eradication of species or degradation of streams |
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• Why has the need for planning risen so much?
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o Rising competition for scarce land, water, biological and energy resources
o The need to protect threatened environments o The desire to maintain or improve the quality of life |
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• After the major decisions are made, what are some areas where technical planning would be important?
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o Environmental inventories
o Forecasting change o Engineering analysis o Environmental impact assessment |
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• What different technical types would participate in this phase of planning?
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o Cultural and physical geographers, geologists, ecologists, hydrologists, wildlife biologists, archaeologists, etc
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• What are the five sequential steps to take to prepare an EIS?
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o Select variables pertinent to the problem
Record them in an inventory Identify their interrelationships o Formulate alternative courses of action o Forecast impacts of the alternatives o Define differences between alternatives – what is to be gained or lost by choosing one over another o Evaluate and rank alternatives, including “no action” and select preferred one. |
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• What is an “impact”? Why is forecasting future impacts so difficult?
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o An impact can be defined as the difference between the environment with a proposed action taking place and with no action taking place.
o Impacts may be direct or indirect |
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• Name five features and resources of study areas that might be in an environmental inventory?
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This provides a catalog and description of features and resources of a study area
o Water features - Archeological sites o Slopes - Wetlands o Microclimates - Valued habitats o Floodplains - Rare and endangered spp o Soil types - Land use o Vegetation associations This also includes an evaluation, or weighted importance of the feature or resource |
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• What is a land capability assessment?
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o These studies determine what and how much the proposed parcel of land can accommodate without degradation.
o May be called capability or suitability assessments o It may differentiate buildable and non-buildable parcels on a project site o The term “carrying capacity” is used in this assessment – of different land units or sub areas. o Land capability and carrying capacity are fundamental to sustainability planning where long-term balance is the goal. |
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• Why is understanding processes of the past important to understanding present landscapes for the purposes of planning?
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o Landscapes, including landforms and soils, are not only products of the past.
o Landscape forms and features today are the products of processes that are still hard at work o Consequently, we can understand the landscape of today by understanding processes of the present era. o We can read past landscape change from observing processes today like drainage features, vegetation, etc. |
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• What are “formative systems” in landscapes?
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o Systems that Form Landscapes
Longshore drift in the coastal zone Wind direction and strength on shore and in deserts Glacial and permafrost systems in mountains & arctic areas Runoff-watershed systems are virtually everywhere- most important landscape forming systems |
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• What is the “form-function” relationship?
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o By understanding form and function relations, we can foresee changes in landscape processes due to development’s changed landscape forms.
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• What is the goal in retaining balance in a development plan?
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o The goal is to achieve balance in function and build a sustainable landscape in which our actions are largely invisible to nature.
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• What is an example of a clue a landscape process may leave behind?
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o processes that formed that landscape.
Examples for streambeds Undercut bank vegetation Debris like twigs and leaves stranded on tree trunks Meanders and point bars Oxbow lakes |
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• What does it mean when we say an area may be in a fragile conditional balance?
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o Most natural landscapes are in balance
Forces of change are met by resisting forces in the landscape (like a thick mat of roots binding soil together) Gravity, chemical cementing agents, vegetation o They resist all but the largest events o Some areas are in a fragile conditional balance slope o and development may “tip” the scale by changing an important ingredient |
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o What is a “linchpin” and how would it trigger a cascade of environmental effects?
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Linchpin” holding environment together – like tree roots on a hillside
o Planners need to guide design of a plan to avoid pulling a “linchpin” and triggering a cascade of unwanted environmental effects Identifying features that may be pivotal in the overall health of the landscape is critical Steep tree covered slopes Vegetated sand dunes Stream banks of root-bound soil Grass covered prairie soils Groundwater seepage zones |
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• Why must our environmental analysis consider more that the site or project area? What systems would a site link?
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Standing at a site, you can imagine being at the intersection of several systems occupying several levels of space above and below the surface.
These systems originate somewhere beyond the planning site and travel somewhere else once they cross it Think of the site as a link in the larger systems overall balance and focus on retaining continuity of flow if landscape plan is to be sustainable |
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atmospheric boundary layer
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Movement of air over the site takes place in a layer called the atmospheric boundary layer, about 1000’ deep
• The exchange of heat, moisture and pollutants with the atmosphere takes place across this layer – the faster the wind blows, the faster the exchange rate |
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landscape/middle tier
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The landscape itself is the middle tier of this model, from vegetation canopies to the reach of roots below the surface
• Water is delivered vertically and runs off horizontally • Development typically results in increased surface runoff and decreased water quality • This is a cumulative problem, passed downhill and downstream |
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bedrock/lower tier
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The lower tier of the site consists of soil layers and underlying bedrock
• This tier has always been deemed important in terms of building foundations and laying utility lines |
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groundwater tier
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Today planners are also concerned with groundwater below the site
• Groundwater moves slowly, so that once contaminated it may take decades to centuries to clean it • It is important to know if the site lies over an aquifer and, if so, is it over the recharge zone or discharge zone? |
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Bedrock
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Bedrock is usually seen as a sign of site stability
• However, in areas of active faults and cavernous limestone it cannot be counted on for stability • USGS records must be searched for earthquake faults near or under a site • Not all limestone collapses or forms caverns |
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• What are sources of environmental data for site planning?
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o Firsthand field observations
o Topographic contour maps o Soil maps o Aerial photographs o Satellite imagery o Special sources USGS CA water resources department EPA NOAA |
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• Important fact – slopes are basically inferior as building sites. Why?
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o Slopes have profound influence on runoff and ground stability
o Runoff is faster and more erosive on slopes |
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• What slopes are best suited to development? What do commercial developers prefer?
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o Conventional development is best suited to slopes less than 15% (8⁰)
o Modern engineering marvels encourage building on steeper and steeper slopes o Commercial developers prefer slopes less than 5% o Roads – the higher the road class, the lower the maximum slope. o Interstates limited to 4% o City streets up to 10% o Driveways can go to 15% |
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• Why are slopes important?
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o Microclimate is also influenced by slope
o Southern exposure is dry, warm, smaller trees o North is opposite - cooler, damper, larger vegetation, more soil development, runoff differences, different plant species and animal habitat |
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• What are ways a slope may be disturbed and later cause problems?
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o Poor analysis and surveys can cause structures to be placed on unstable or potentially unstable slopes
o Disturbance of slope environments is the most common source of slope problems Mechanical cut and fill Deforestation Drainage alteration |
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• Know the equation for per cent slope
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o % slope = change in elevation/change in distance * 100
(rise over run) |
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Degree of a slope
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o Degree of slope
0% = 0⁰ 50% = 26.5⁰ 100% = 45 ⁰ (53 actually) |
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• What are the different ways degrees and percentages of slope are used?
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Degrees are used commonly in engineering applications for slope stability
Percentages are used in planning applications i.e. Slope classification, grading, mapping |
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• How many degrees is a 100% slope?
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45 degrees
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• Lithology
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o For any earth material (gravel, sand, boulders, clay) there is an angle of repose
This angle varies widely for different material It can be 90° for strong bedrock, less than 10° in loose, unconsolidated material Silt and clay are especially variable – vegetation, internal structure of particle mass all come into it Clay loses its cohesiveness when saturated – water interferes with the ionic bonds holding the particles together |
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o Vegetation (plant cover) controls
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Stability aided by roots is limited to the surface layer
Can increase stability for sands up 10° to 15° from the 33° they normally have This is a state of “conditional” stability, called metastable Plant cover also reduces soil water content, reducing instability Can dewater a slope by 40% of precipitation infiltration In CA wildfire zones, a big problem… once plants are gone, saturation weakens surface materials |
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• What are the basic slope forms
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o Straight
o S shape indicates long-term stability and equilibrium o Concave Signs of former failures o Convex Resistant bedrock in center OR slope retreat at foot o Irregular Differing resistance to weathering from different strata o Always look at the big picture to see if a particular slope form is out of equilibrium with the rest of the landscape |
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• What would you look for to assess a slope?
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o Look for a history of instability
Air Photos can show: Scars or scarps Vegetation differences Different soil types o Be aware of deforestation Without plant cover failure much more likely Plant cover can de-water o Earthquakes Jar bonds between particles, resistance to failure is reduced especially on steep angle slopes 1994 6.7 Northridge triggered more than 11,000 slope failures in the area o Assess undercutting Undercutting action from waves, rivers or human excavation Results in steeper inclinations - less confining pressure on lower slope Increases failure potential Road cuts • slope may be weakened • groundwater may be intercepted |
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• What is wrong with engineering slope models?
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o Engineering slope models are too simplistic because natural slopes are too complex in composition and drainage
o Land use alterations must be considered o Integration of all the proceeding variables is necessary in a systems-based approach of evaluation o All slopes are part of watersheds o All are critical to operations as both hydrologic and geomorphic systems |
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• What two soil properties are used to describe soil conditions for development?
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o Texture and Composition are most important
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Composition
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Composition refers to the material that make up a soil
• Mineral particles • Organic matter • Water • Air |
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Organic matter content
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Organic matter content may vary greatly in soils.
• On the negative side, organic particles result in weak skeletal structures with low bearing capacities. o Organic matter can compress and settle differentially under loads o When moisture is lost, it can lose much volume o Deep organic soils pose an impediment to development and land use in general On the positive side, organic material is essential to soil fertility and hydrology Organic soils have great water storage capacity – it reduces water runoff rates |
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• What is bearing capacity and which types of soil have the highest? Lowest?
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o Bearing capacity is a soil’s resistance to penetration from a weighted object, like a building foundation.
Sand and gravel provide greatest stability Clays have lower bearing capacity • Wet masses of clay can compress and slip laterally under a load |
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• What is soil texture? What information does the field hand test provide?
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o Texture describes the composite sizes of particles in a soil sample (several handfuls in a field sample)
o Particles in soil vary in size, from microscopic clay to gravel to large boulders. o Sand, silt and clay are the most common particles in soil o These can be sorted out through a sifting process, called sieve analysis, then weighed and given a percent to show soil composition |
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• The field hand test!
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– This is a quick way to estimate texture and classify soil type.
– Extract a damp handful of soil and squeeze it into three basic shapes: • A cast (lump) • A thread (rolling it) • A ribbon (squeezing it flat) – Behavior of soil in the test is determined by the amount of clay in the sample. – Clay particles are highly cohesive and when damp, act together like plastic. – The higher the clay percentage in a soil sample, the more malleable and durable the sample will be. |
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• Infiltration capacity
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– The rate at which water penetrates the soil surface (cm/hr)
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• Permeability
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– The rate at which water in the soil moves through a given volume of soil material (cm or inches/hour)
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• Percolation
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– The rate at which soil takes up water in a soil pit or pipe in the soil (often used in septic systems and waste water disposal) in inches/hr
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• What does “poor soil drainage” mean?
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– Soil is frequently or permanently saturated and may often have water standing on it.
• After three hours of infiltration the above soil becomes saturated. The problem is an already high water table |
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Capillary water
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– Molecular water in soil
• held in place around and between particles by force of cohesion between water molecules • Not held strongly enough that plants cannot access it • Water molecules may also still move along gradients from wet to dry areas • Molecular soil moisture is thus moved to the surface in dry weather, where it is evaporated to the atmosphere |
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Gravity water
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– Water that moves in the spaces between particles
– It moves in response to the forces of gravity… downward through the soil – At some depth, it accumulates to saturate the soil and rock to become groundwater – At this point, all available spaces between particles are filled with water, forcing air out. |
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• What is groundwater? What is the major issue with groundwater for planning purposes?
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o Groundwater is water found in the pores of soil and sediment, plus narrow fractures in bedrock
o Groundwater is the largest reservoir of fresh water that is readily available to humans o Many communities depend on groundwater for most of their water – in fact, even Los Angeles gets 1/3rd of its water from groundwater. o For planning purposes, the major issue with groundwater is pollution, or contamination. o Care must be taken as groundwater is the largest easily available source of freshwater on the planet. o At the site scale, groundwater may actually surface if it is in a shallow aquifer. |
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• What is it important for planners to know about groundwater?
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o All Groundwater Begins and Ends in the Landscape
Therefore, land use activity on the surface can and does affect groundwater. Planners must know which activities tend to be polluting Proper sites should be found for polluting activities Buried waste – new landowners discover unrecorded sources of pollution Leaking storage tanks Landfills with hazardous waste |
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o Belt of soil moisture
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water held by molecular attraction on soil particles in the near-surface zone
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o Zone of saturation
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Water not held as soil moisture percolates downward drawn by gravity
Water reaches a zone where all of the open spaces in sediment and rock are completely filled with water Water within the pores is called groundwater |
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o Water table
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the upper limit of the zone of saturation or the transition zone between this and zone of aeration. Variations in the water table
Depth is highly variable Varies seasonably and from year to year Shape is usually a subdued replica of the surface topography |
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o Capillary fringe
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Extends upward from the water table
Groundwater is held by surface tension in tiny passages between grains of soil or sediment |
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o Zone of aeration
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Area above the water table
Includes the capillary fringe and the belt of soil moisture Water cannot be pumped by wells from this zone (duh…) |
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o Depth of groundwater
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Water content lessens with depth
Upper 5000’ feet is the zone of usable groundwater Content may vary with different soil and rock materials |
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o Porosity
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percentage of total volume of rock or sediment that consists of pore spaces
• Determines how much groundwater can be stored • Variations can be considerable over short distances |
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Porosity of common materials
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• Granite 0–5%
• Shale < 10% • Sandstone 5–30% • Sand and Gravel (mixed) 22–35% • Sand and Gravel (well sorted) 25–50% • Clay 33–60% |
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• Permeability
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– the ability of a material to transmit a fluid
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• Aquitard
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– an impermeable layer that hinders or prevents water movement (such as clay)
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• Aquifer
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permeable rock strata or sediment that transmits groundwater freely (such as sands and gravels)
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• Where is the zone of usable ground water?
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Upper 5000’ feet is the zone of usable groundwater
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• The shape of the water table usually follows the shape of what?
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Depth is highly variable
Varies seasonably and from year to year Shape is usually a subdued replica of the surface topography |
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• Why are groundwater environments complicated in the West?
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o Varied GW environments in the West
o Diverse terrain, faulting result in complicated systems |
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• Describe the movement of groundwater compared to water on the Earth’s surface?
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o Movement of groundwater is Exceedingly slow – typical rate of movement is a few centimeters per day
o Energy for the movement is provided by the force of gravity |
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• What is Darcy’s law?
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o Darcy’s Law – if permeability remains uniform, the velocity of groundwater will increase as the slope of the water table increases
Hydraulic gradient – the water table slope, determined by dividing the vertical difference between the recharge and discharge points by the length of flow between these points Rise/Run Hydraulic head – the vertical difference between the recharge and discharge points |
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What is the hydraulic gradient?
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Hydraulic gradient – the water table slope, determined by dividing the vertical difference between the recharge and discharge points by the length of flow between these points
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• What is a recharge zone? Why must planners be careful in these zones
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o Recharge zones are places surface water is supplied to the groundwater body
May be where stream water accumulates Where there is highly permeable soil or rock Where the aquifer is exposed at or near the surface These zones are also points of easiest access for contaminents! |
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• What is a cone of depression from a well?
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o Drawdown (lowering) of the water table
o Cone of depression in the water table |
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• What are planning considerations for groundwater at a site? What is the best response to groundwater bodies intercepted during grading?
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o Problems may arise when shallow groundwater bodies are intercepted during grading and excavation
o Creates low pressure point in the system o Induces rapid seepage and erosion by sapping o Leads to slope failure o Excavation of seepage area only exacerbates problem o Removing vegetation also makes problem worse o Appropriate response is to modify the plan – realign or redesign and leave seepage zone alone |
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• How does saltwater contaminate groundwater
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o Saltwater contamination
Excessive groundwater withdrawal causes saltwater to be drawn into wells, thus contaminating the freshwater supply Primarily a problem in coastal areas |
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• How did MTBE get into our groundwater
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o Began in 1979
o Great for Air = Horrible for Groundwater o High Solubility o Potential Human Carcinogen in high Doses o No EPA regulation standard o Seepage out of underground gas tanks |
