water use and pollution Flashcards
what is surface water?
A renewable resource consisting ofrivers, lakes and reservoirs
what is groundwater?
Collects underground in aquifers. Some aquifers are non-recharging, and thus nonrenewable resources.
what is the potential for water scarcity?
there is an increase in demand for water due to growing population, groundwater levels are declining in many areas and the water quality is also a growing pobelm with over 600 million people lacking access to clean water in 2006 study by UNDP. there is an imbalance between water withdrawels per capita and renewable freshwater resources per capita
what is green water?
Green water is that fraction of rainfall that infiltrates into the soil and is available to plants. It includes soil water holding capacity and the continual replenishment of reserves by rainfall.
what is blue water?
Blue water is the water in our surface and groundwater reservoirs.
what is grey water?
Grey water is the water that becomes polluted during production, say in agriculture because of the leaching of nutrients and pesticides
what is virtual water?
It is the volume of freshwater used to produce the product, measured at the place where the product was actually produced.
why is virtual water important internationally?
For water-scarce countries (e.g., Morocco ), it would be attractive to achieve water security by importing water-intensive products (grain and seed oil)
Water-rich countries can profit from their abundance of water resources by producing water-intensive products for export.
what does an efficent allocation of scarce surface water depend on?
An efficient allocation of a renewable resource involves a contemporaneous opportunity cost or the cost imposed on an alternative user
Efficiency in the presence of competing uses implies that marginal net benefit should be equalized across all uses
what does the efficient allocation of the scarce ground water depend on?
For groundwater, there is a marginal user cost reflecting the inter-temporal opportunity cost.
If withdrawals exceed recharge, the resource is (a)either depleted over time, or (b) use is stopped when marginal extraction cost exceeds marginal benefits.
what are sources of inefficiency in the current alloaction system of water?
Restrictions on Transfers, municipal and industrial water pricing, federal reclamation projects and agricultural water pricing
how do restriction on transfers a source of inefficiency?
Property rights and transferability will lead to efficient allocation₋ “use-it-or-lose-it” exacerbates inefficiency, no incentive to conserve₋ The ‘preferential-use doctrine’ gives certain users priority during shortage, regardless of the marginal net benefit produced by use
how does munuicipal and industrial water pricing be a source of inefficiency?
Subsidized water leads to inefficiencies and waste₋
Efficient pricing requires price to equal marginal cost of supply (inclusive of extraction, treatment to standard, delivery to point of use)
how does federal reclamation projects and agricultural water pricing be a source of ineffiency?
Governments subsidize water projects even when they fail CBA to encourage economic development and employment
what are the potential remedies for these sources of inefficiency?
relaxing “use it or lose it” restrictions
water markets
water pricing
how will relaxing use it or lose it restrictions remedy inefficency?
Encourages conservation, and allow water to move to higher valued uses by allowing owners to sell conserved water
how do water markets remedy inefficiency?
Increasingly utilized to correct inefficiencies and remove scarcity in the short or long-term basis
what are examples of water markets?
one example is the colarado river compact. the colarado river is a major water source for several western states including Arizona, California, nevada, new mexico, utah, and wyoming. the colarado river compact is a legal agreement that aloows for water to be transferred from areas that have a surplus to areas that are in need
how is water pricing a remedy for inefficiency?
Elimination of subsidies would reduce inefficiencies₋
Adequate charge rate structures encourage conservation
what is point source pollution?
discharged into surface water at a specific location through a drainage pipe or ditch. the primary sources are industries and municipalities
what are nonpoint source pollution?
runoff from a variety of sources (agricultural / urban runoff). it is more difficult to control due to unpredictability and uncertainty associated with the exact source
what are the two types of water pollutants?
1- fund pollutants
2- stock pollutants
what are fund pollutants?
Fund pollutants are those that can be assimilated by the environment. an example is excess plant nutrients
what are stock pollutants?
Stock pollutants are those for which the environment has no absorptive capacity. an example of these are persistent pollutant which break down slowly and can travel long distances in water such as heavy metals
