Understanding Water Resources & Pollution: Hydrologic Cycle, Groundwater & Scarcity - Prof, Study notes of Geography

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Geog 1125 Hopkins Final Study Guide  Water (H2O) o Originally formed within the earth and brought out by outgassing  The release of a gas that was dissolved, trapped, frozen or absorbed in some material  71% of Earth’s surface area  70% of human body o Distribution:  97.22% in oceans  2.78% in freshwater  77% in glaciers, 22% groundwater, 1% in lakes/ponds/rivers  Hydrologic Cycle o Evapotranspiration  Sublimation is from solid to gas o Condensation o Precipitation o Run-off  Groundwater o 2nd largest potential source of freshwater o Accumulated by percolation through soil into reservoirs or aquifers  Aquifer : A body of permeable rock that contains or transmits groundwater o How well the water percolates depends on:  Porosity : the % of rock or soil that is void (pore) space; how much water it can hold  Permeability : capacity of a substance to transmit fluids through it o Passes through aeration zone and collects in zone of saturation  Aeration zone : A region below the Earth's surface that is marked by the presence of both water and air in the pores of rocks and soil  Greater than 0.01 m/day permeability  Zone of saturation : impermeable region below aeration zone  Less than .01 m/day permeability  Water table : upper limit of zone of saturation o Unconfined aquifer : permeable layer above it and impermeable layer under it o Confined aquifer : impermeable layer above and below it o 3 types of impermeable layers  Aquitard : a layer that doesn’t allow enough water to pass through to be used for water supply  Aquiclude : an impermeable formation which may contain water but which is incapable of transmitting a significant amount of water (clay)  Aquifuge : an impermeable formation neither containing nor transmitting water (granite) o Artesian Well : A flow of water onto the surface under pressure o Spring : A surface flow of water that emerges from underground, not under pressure o Stream : Water flowing on the surface, in a watercourse, where the water table is above the surface; permanent or temporary  Water Uses o How much?  Humans withdraw about 35% of the world’s reliable runoff  Usage may double in the next two decades with some exceeding reliable surface runoff  US has plenty of fresh water, but most in bad locations or polluted  East better off than West because of higher precipitation o What for?  70% for irrigation (on 18% of world’s cropland to make 40% of food)  Industry accounts for another 20%  Remaining 10% to cities and residences  Water Scarcity: o Causes:  Dry climate : not enough precipitation to meet needs  Drought : period of 21 or more days with precipitation 70% below normal  Desiccation : drying of soil due to deforestation and overgrazing  Water stress: low availability due to increasing population relying on limited supplies o Effects of causes  ~500 million people live in countries with water stress  1.2 billion cant afford safe drinking water  People killed or made refuges from droughts o Potential problems  Population increase: water demand  ~ waste of limited supplies  ~ and pollution   Ex. China, India, Africa, Middle East, South America  Can lead to violence over water  Ex. Middle East: along Nile, Jordan River Basin; Tigris & Euphrates rivers  Increasing industrialization in developing nations increases usage and pollution  Solutions o Dams and Reservoirs o Benefits: controlled supply, hydroelectricity, supply for irrigation & industry, recreational activities and jobs  Costs: ecological damage, large building costs, changes down river flow dynamics, sediment buildup o Water Transfers : transfer via tunnels, aqueducts, and underground pipes from reservoirs  Benefits: gets water to where it’s most needed  Costs: ecological damage, increased pollution, potential for increased wasted water due to lower prices  Ex. California Water Project, Aral Sea o Withdraw more from groundwater sources  Benefits: done annually, less loss to evaporation, often less expensive  Costs: if withdrawn faster than replenished results in lowering of water table, aquifer depletion, aquifer subsidence, saltwater intrusion in coastal areas, reduced stream flow o Desalination : removing dissolved salts from ocean water  Distillation : heating saltwater until it evaporates  Reverse Osmosis : saltwater pumped at high pressure through a membrane that allows water but not salt to pass through  Advantages: ample supply of saltwater in coastal areas  Disadvantages: high energy demand, produces large amounts of waste water (brine) with high levels of salt and minerals  Currently supplies 0.2% of world water needs o Harvest from ice caps/sheets  Not economically feasible now, but melt water from alpine glaciers is common in many areas  Water Overabundance (Flooding) o Usually seasonal o Can revitalize floodplains and recharge groundwater o Loss of life o Property damage o Risks can be reduced by:  Straightening and deepening streams  Levees  Dams o Humans are a species of rules, many of which relate to how they interact with the other components of the environment o Most human groups, societies, countries, have selected individuals (politicians/leaders) to create these laws/rules  Components of Environmental Policy Decision Making o Government: legislative, executive, judicial branches o Business: large and small companies and their lobbyists o Environmental groups: mainstream (Green Peace, Sierra Club, and other Non-profit Non- Governmental Organizations) and grassroots or local citizen’s groups and their lobbyists o Individuals: those who are engaged in affecting the outcome of laws; voters, individual lobbyists o Various other special interest groups: groups who may be affected by changes to env. laws; ranchers, farmers, fishermen, campers, recreationists  Principles which should Give Decision Making o Humility Principle : recognize and accept that humans have a limited capacity to manage nature because our understanding of nature and consequences of our actions is quite limited. o Reversibility Principle : try not to do something that can’t be reversed later if the decision turns out to be wrong o Precautionary Principle : when evidence indicates an activity raises threats of harm to human health or the environment, take precautionary measures to prevent or reduce such harm, it is better safe than sorry o Prevention Principle : whenever possible, make decisions that help prevent a problem from occurring or getting worse o Integrative Principle : make decisions that involve integrated solutions to environmental and other problems o Environmental Justice Principle : establish environmental policy so no group of people bears an unfair share of the harmful environmental risks from industrial, municipal, and commercial operations, or the execution of laws, regulations, and policies  Policy-Making in the US o Basic steps  Laws passed by legislative branch  Regulations instituted by executive branch to put laws in effect  Funding to implement and enforce the laws and regulations (E & L)  Often judicial is called upon to determine validity of a law o Done by:  Lobbying to lawmakers that an environmental problem exists and the govt. has responsibility to address it  Usually done by NGO’s, special interest groups, or individuals  Special interest groups and other that oppose a proposed law will lobby against it  Both sides try to influence how the laws are written  Proposed laws are evaluated by committees within legislative branch where lobbying takes place  Once law is passed by L, must be signed into law by E  Funding to implement/enforce is appropriated  Have appropriate govt. department or agency to draw regulations for implementation  Implement and enforce laws  Special interest groups, NGO’s, business, or any affected group may take agency/govt. to court for failing to implement/enforce the regulations, or for enforcing too rigidly, or because they want to change or abolish the law o This is often called the Policy Life Cycle  Recognition  Formulation  Implementation  Control  Outcome o Thousands of laws for human-environment interaction  Clean Water Act, Clean Air Act, Endangered Species Act o New departments and agencies created to deal with the interactions  EPA, Council on Environmental Quality o Creation of non-governmental organizations, citizen’s groups, and other organizations for envt matters o Jobs created as result of laws (lobbyists, organizations, enforcement, o Jobs lost as result of laws due to affect on companies o Lifestyle changes o Cleaner environment, some species saved from extinction, new technology, greater environmental awareness