Energy and the Environment Exam 3

weathering

breaking up of Earth materials into progressively smaller and smaller pieces

erosion

transportation of weathered materials by water, wind, glaciers, and gravity

deposition

the “depositing” of weathered materials

the hydrological cycle (water cycle)

• important control on where water is at any given point in time on Earth

• states of matter - solid, liquid, and gas

lysimeter

buried containers of soil equipped with a weighing device and draining system to measure evapotranspiration and percolation

evapotranspiration

loss of water from the soil from both by evaporation from the soil surface and by transpiration from the leaves of the plants growing on it

why is soil moisture important in water budgets?

• area of storage

• pathway to groundwater

what does surplus mean in a water budget?

more water is available than is being used

why are water budgets different for these examples:

• Tennessee

• Canada

• Arizona (big deficits)

groundwater

water present beneath the earth’s surface in rock and soil spaces and in the fractures of earth formations

how do households and industry contaminate groundwater?

aquifer

rock/sediment capable of storing and/or transmitting water

• unconfined aquifer - open to the surface

• confined aquifer - between impermeable layers

• zone of aeration - air-filled part of the aquifer

water table

top of the saturated zone

aquiclude

impermeable layer

cone of depression

hole in water table from pumping

effluent

flowing out

influent

flowing in

point and non-point pollution sources

• point - you know the exact source

• non-point - you don’t know the exact source

artesian

water rises in a well without pumping

aquifer recharge and discharge

what does it mean to overdraft an aquifer?

use more water from the aquifer than is coming back into the aquifer

how does salt water intrusion occur?

over-pumping wells and aquifers

water quantity vs quality

• water quantity - amount of water available for use

• water quality - chemical constituents in water compared to government standards

why is there an uneven distribution of water resources around the world?

related to the climate and usage of water

U.S. water budget

how much water is available at a given place at a given point in time

what can overdraft lead to?

• formation of cone of depression

• salt water intrusion

• water scarcity

• using inferior sources for drinking water

water scarcity in the context of water quality can lead to…

…using inferior sources for drinking water supplies

Water Quality Protection

U.S. Safe Drinking Water Act and Clean Water Act

fluvial process

work done by running water, they also carve and bury landscapes

within the process, there is:

• overland flow - surface water running downslope

• stream flow - channelized movement of water in a valley

in a fundamental sense, the Earth’s surface is comprised of a system of…

• valleys - total portion of the Earth’s surface where drainage systems are clearly established

• interfluves - higher land above the valley sides that separate adjacent valleys (land between valleys)

what are fluvial landscapes a mixture of?

erosional and depositional landforms

four kinds of erosion associated with overland flow which lead to streamflow:

1. splash erosion - produced by impact of individual raindrops

2. sheet erosion - water flowing across Earth’s surface as thin sheets

3. rill erosion - sheet flow disaggregates into tiny channels called rills

4. gully erosion - if erosion continues, rills join to form larger channels called gullies

   *now approaching streamflow in a channel*

two kinds of weathering/erosion associated with streamflow

1. abrasion - grinding/chipping action of rocks and sediment in a stream on other rocks and sediment

2. corrosion - chemical action in streams which chemically breaks down rocks and sediment

stream’s load

weathered material transported by stream, streams carry three types of load:

1. dissolved load - minerals and salts carried dissolved in the stream water

2. suspended load - carried suspended in the stream; velocity dependent (faster=larger)

3. bedload - sand and larger that rolls (traction) and bounces (saltation) along the bed of a stream

alluvium

stream deposited material/weathered broken-up materials transported by the stream

stream discharge

the volume of water a stream carries moving past a given point over a given amount of time

gradient

• water flows in a stream because of this

• elevation a stream drops over a given distance

stream gradient decreases from _______ to _______

head waters (where stream begins) to mouth (where stream ends)

stream life cycle based upon channel shape:

1. youth (infant) - braided channel, stream has multiple channels which converge and diverge

2. adolescent - stream cuts a v-shaped valley with numerous straight segments of stream channel

3. mature - meanders begin to develop (symmetrical bends in stream channel)

4. very mature - well developed very symmetrical meanders develop

5. old age - large symmetrical meanders develop as well as ox bow lakes (cut off meanders)

6. rejuvenation - process starts over, caused by uplift of landscape, braided stream again

drainage basin

area that contributes water to a specific stream; small streams join larger

flooding

discharge exceeds the capacity of the stream channel; water then spreads to the floodplain (flat land adjacent to the stream channel)

flood recurrence interval

how often you would expect to have a flood of a certain magnitude