HUMAN IMPACT ON THE ENVIRONMENT: POST MIDTERM
ALL are rather extensive and reading through this once and simplifying
it in the process would be more than enough review for all!!! Great
work everyone and good luck!
Week 7 Readings: Pages 249 252, 265 278, and Chapter 13:
Chapter 12: The Hydrologic Environment: Precipitation, Land
use, and Water Resources
- All water frozen is in polar ice caps
- Hydrologic condition of earth essential to understand life and
- Most important factor of life = water
- Water delivered by atmosphere to land as part of weather
- Water supply uneven geographically
- People manipulate water system(s)
The Hydrologic Cycle:
- Five natural reservoirs of water: 1) oceans 2) Glacial ice caps 3)
Groundwater 4) Surface water 5) Atmosphere
- Ocean holds most
- Glacial ice = largest reservoir for freshwater
- The rest are sources that humans and organisms depend on for
- Hydrologic Cycle: flow-system characterized by exchanges of
water among five major reservoirs. Supplies water to land
masses. And, exchanges saltwater for freshwater
- Driven by heat of earths absorption of solar radiation.
- Heat triggers evaporation, making water vapor
- Condensation makes vapor into water droplets
- Most lands on oceans, not land - Transpiration also returns water into the atmosphere, when
coupled with evaporation
- Groundwater released from land through stream and river
- Atmosphere exchanges on average every nine days
- Precipitation Process: 1) Condensation of water vapor from
atmospheric cooling. 2) Particles form into droplets to fall
- Condensation nucleus: airborne particle from natural or human
- Debris and pollution effect precipitation, joining it as it hits
ground...acid rain, acid clouds, and acid fog.
- When temperature drops, capacity of air to hold water vapor
declines until condensation sets in.
- Dew Point: Temperature when air is 100% fully saturated
- Condensation increases fast when temperatures below dew point
or when condensation nuclei are abundant
Types of precipitation:
- Convectional storm: type of precipitation that takes place when
air moves into a low-pressure trough or topographic depression
and escapes by moving upward; precipitation in the equatorial
zone is at least partially convergent
- Thermals: Rising upward flow of air currents from the surface
- Storm can become turbulent with release of heat
- Impact this has includes flash floods, climate change, and wind
- Convectional precipitation affected by global warming.
- Thunderstorms fueled by heat vapor
- Groundwater: accumulation of liquid water in rock and soil
- Largest supply of liquid water on earth - Aquifers: Materials containing large amounts of usable
- Porosity: total void space available among particles or in the
cracks where water can reside
- Water budget: an practices of an aquifer as a water system
- Inflow: Process of surface water percolating down from soil
- Outflow: Process of seepage into streams, evaporation, etc.
- Recharge: process of groundwater/soil water being replenished
- Discharge: The rate of water flow in a stream channel; measured
as volume of water passing through a cross section.
- Safe aquifer yield: Rate of water being pumped from an aquifer
without significant decline in aquifer
- At our consumption rates aquifers being depleted.
- Salt water intrusion: Invasion of saltwater into fresh groundwater
because of over pumping of the fresh groundwater
- This leads to well contamination
- This can be prevented through limited urban growth
Lakes, Ponds, and Wetlands:
- Water table: uppermost surface of the zone of groundwater
- Natural impoundment: Seepage water accumulation in a low spot
where a stream is limited/nonexistent. This creates a
wetland/body of water
- Water balance: Impoundment characterized by relatively
permanent body of water that fluctuates seasonally through
changes in inputs and outputs.
- Wetlands: characterized by shallow water with heavy growth in
aquatic or semi aquatic plants, and thick organic deposits.
- Wetland systems: marine, riverine, etc.
- Wetlands been destroyed and drained through farming and
- Eradication: agriculture causing complete destruction of the
wetlands - Lakes and ponds characterized by sizable areas of open water,
enough to inhibit aquatic life.
- Eutrophication: water body becomes overgrown with plants fed
by nutrients carried through runoff, depleting the water source.
Human Use of Water:
- We use way too much water
- Domestic, municipal, industrial, agricultural, and power
- Ways to reduce use: land planning, recycling, change laws, use
storm water, fix delivery systems, reduce use, change designs of
landscape, reduce irrigation applications.
- Huge problem is the inconsistency of global supplies
- Some have high demand and little water, and vice versa.
- Privitation of water supplies could limit our use
- Consumptive: Water use in which the water is not returned to the
environment in a liquid form
- Nonconsumptive: water is returned back into the environment
- Degrading: As we consume and dont return water as a resource,
- Dams and water diversions effect water flow, and speeds
- Water Management: Prioritizing a system of management of
water as a resource
- Prior Appreciation: A method of water allocation in which rights
of water are assigned on a predetermined basis
- Riparian Rights: A method of water allocation based on first
come, first served for users bordering on a stream.
- Sustained use: Using water in a sustainable manner that
maintains the quantity and quality
Chapter 13: Water Pollution: Patterns, Trends, and Impacts
Types of water Pollution:
- Oxygen-demanding wastes