Water

Question 1

functions of water

Answer 1

• moderating climates by storing heat
• geochemistry
• fluvial landscape evolution
• medium for nearly all organic processes
• aquatic and marine habitats
• removes and dilutes waste

Question 2

hydrologic cycle

Answer 2

closed material cycling system powered by solar energy and gravity, involves complex movements/pathways that are connected (surface-atmosphere exchanges, surface and subsurface pathways, uneven spatial and temporal distribution)

Question 3

important processes in the water cycle

Answer 3

• evapotranspiration: water turns from liquid to gas
• condensation: turns from gas to liquid
• precipitation: returns to surface
• infiltration and percolation: absorbed into the ground
• runoff: pulled by gravity to lower locations

Question 4

the roles of wetlands in the water cycle

Answer 4

• extremely valuable biodiversity
• able to slow and store runoff water
• reduce flooding
• recharge aquifers (since surface water flows slowly, this allows water to absorb into the ground)
• filter pollutants (during the process of water absorption, this filters the water to become cleaner)

Question 5

watershed

Answer 5

high point boundary that allows water to move towards a lower location of water, rivers form drainage networks, tributaries converge to form higher order streams

Question 6

groundwater

Answer 6

flow rates are slow, takes a long time to naturally replace groundwater, water table divides the unsaturated (combo of water and air) from the saturated (no air) zones, table moves depending on groundwater supply, when intersecting the land surface, the table forms rivers and lakes

Question 7

human uses of water

Answer 7

• in-stream: used wherever it’s found (ex. using rivers for transport)
• off-stream: water is withdrawn and used elsewhere (ex. irrigation)
• consumptive: not returned to the source (ex. watering crops)
• non-consumptive: returned to the source (ex. renewable hydroenergy)

Question 8

water-mining

Answer 8

process of withdrawing water faster than it can be replenished

Question 9

impacts of ag on water

Answer 9

biggest water consumer, over-irrigation causes soil waterlogging and salinization, affects water table, too much will prevent plant uptake and may be sucked into the atmosphere, leaves pollutants like salts that prevent plant growth

Question 10

quantitative impacts

Answer 10

involve the amount of available water supply

Question 11

qualitative impacts on water

Answer 11

• redistribution and flow alterations (ex. dams and channels that send water elsewhere)
• impoundments: blocking a minor flow to create a larger one (ex. reservoirs and constructed waterbodies)
• source depletion (ex. withdrawal of water from waterbodies)
• surface water withdrawal/diversion
• changed hydrological processes due to altered landscapes (ex. deforestation contributes more sediment than a river can handle, which changes the slope and interrupts evapotranspiration)
• flood aggravation: tendency to develop in flood-prone areas and stems from alterations to watersheds

Question 12

impacts of pollution on wetlands

Answer 12

• drainage/infilling of wetlands (taking water out to place soil for ag or urbanization)
• cultivation/grazing of riparian zones (encroaches on vegetation near the wetland, breaks connection between the land and wetland and makes processes less effective)
• sediment/nutrient transport in runoff (allows algae to grow which consumes all O2 and makes it difficult for other living things)
• ruins filtration processes (which are important to having clean water supply)
• reduces biodiversity

Question 13

water pollution

Answer 13

physical, chemical, or biological change in water that adversely affects the health of humans and other organisms

Question 14

sources of water pollution

Answer 14

• natural: from various biophysical processes
• anthropogenic: from humans
• eutrophication: nutrient enrichment of water body

Question 15

point source

Answer 15

able to be seen and defined; ex. animal feedlots, sewage treatment, factories which contaminate water with nutrients, waste, and bacteria

Question 16

diffused source

Answer 16

interrelated causes and effects; ex. farms (contaminates with fertilizers, pesticides), residential areas (contributes salt, oil, grease, chemicals), construction sites (erodes soil), and abandoned mines (acid drainage)

Question 17

oligotrophic waterbody

Answer 17

has few nutrients and clear water

Question 18

eutrophic waterbody

Answer 18

has excess nutrients but little O2, which results in cloudy water

Question 19

deadzones

Answer 19

created at the direct output source of pollution, cannot sustain life

Question 20

sewage treatment

Answer 20

used to reduce water contamination by filtering waste and purifying/disinfecting the water, allows discharge to surface water, some systems reuse the treated water instead of returning it to the waterbody

Question 21

groundwater pollution

Answer 21

increasingly becoming contaminated, has delicate filtration processes, difficult to monitor, can retain contaminants for a long time since they take longer to break down naturally,

Question 22

ocean pollution

Answer 22

contamination of coastal zones is worsening, dead/hypoxic zones have increased, waste disposal circulates thru the oceans by currents and winds