Chapter 5 Geology

Porosity

Percentage of pore spaces and determines storage of groundwater

What are the five that are involved in the water process?

Precipitation Evaporation infiltration Runoff Transpiration

Which drainage pattern develops on isolated volcanic cones or domes?

Radical pattern

Which drainage pattern develops on highly jointed bedrock?

Rectangular pattern

Contrast bedrock and alluvial stream channels. Distinguish between two types of alluvial channels.

- - - Meanders change shape through erosion a the cut bank (the outer edge of the meandor) and deposition of sediment on point bars (the inside of a meander). A meandor may become cut off and form an oxbow lake

Contrast narrow V-shaped valleys, braod vallleys with floodplains, and valleys that display incised meanders.

- A stream valley includes the channel itself, the adjacent floodplain, and the relatively steep valley walls. Streams erode downward until they approach base level, the lowest point to which a stream can erode its channel. A river flowing toward the ocean ( the ultimate base level) may encounter several local base levels along its route - A stream valley is widened through the meandering action of the stream, which erodes the valley walls and widens the floodplain. If base level were to drop or if the land were uplifted, a meandering stream might start downcutting and develop incised meanders.

Discuss streamflow and the factors that cause it to change.

- The flow of water in a stream may be laminar or turbulent. A stream's flow velocity is influenced by channel gradient; size shape and roughness of the channel; and discharge - A cross-sectional view of a stream from head to mouth is a longitudinal profile. Usually the gradient and roughness of the stream channel decrease going downstream, whereas the size of the channel, stream discharge, and flow velocity increase in the downstream directional

Outline the ways in which streams erode, transport, and deposit sediment.

-Streams erode when turbulent water lifts loose particle from the streambed. The focused "drilling" of the stream armed with swirling particles also creates potholes in solid rock -Streams transport their load of sediment in solution, in suspension, and along the bottom (bed) of the channel. A stream's ability to transport solid particles is described using two criteria: Capacity refers to how much sediment a stream is capable moving. -Streams deposit sediment when velocity slows and competence is reduced. This results in sorting, the process by which like-size particles are deposited together

Describe the nature of drainage basins and river systems.

-The land area that contributes water to a stream is its drainage basin. Drainage basins are separated by imaginary lines called divides. - As generalization, river systems tend to erode at the upstream end, transport sediment through the middle section, and deposit sediment at the downstream end.

Discuss the formation of deltas, naturally levees, and alluvial fans.

A delta may form where a river deposits sediment in another water body at its mouth. The partitioning of stream flow into multiple distributaries spreads sediment in a different direction. -Natural levees result from sediment deposited along the margins of a stream channel by many flooding events and flows parallel to the main river -Alluvial fans are fan-shaped deposits of alluvium that form where steep mountains fronts drop down into adjacent valleys

What are some man-made flood controls?

Artificial levees Flood-control dams Channelization

What factors increase downstream: Channel size, gradient, slope, or channel roughness?

Channel size

Which drainage pattern develops on uniform surface material?

Denritic Pattern

The work of stream is erosion and transportation, what are the three types of loads?

Dissolve load, Suspended load, Bed load.

Rapids and Waterfalls are *not* characteristics of narrow valleys. True or False.

False. They are charactersistics

Discuss the causes of floods and some common flood control measures.

Floods are triggered by heavy rains and or snowmelt. Sometimes human interference can worsen or even cause floods. Flood control measures include he building of articificial levees and dams.

What factors decrease downstream? : Channel size, gradient, slope, or channel roughness

Gradient Slope Channel roughness

List and discuss three important environmental problems associated with groundwater.

Groundwater can be mined by being extracted at a rate that is greater than the rate of replenishment. -The extraction of groundwater can cause pore space to decrease in volume and the grains of loose Earth materials to pack more closely together - Contamination of groundwater with sewage, highway salt, fertilizer, or industrial chemicals is another issue of critical concern.

Explain the formation of caverns and the development of karst topography.

Groundwater dissolves rock, in particular, limestone, leaving behind void spaces in the rock. Caverns form at the zone of saturation -Dripstone is rock deposited by dripping water containing dissolved calcium carbonate inside caverns -Karst topography develops in limestone regions and exhibits irregular terrain punctuated with many expressions called sinkholes. Some sinkholes form when the cavern roofs collapse

Discuss the importance of groundwater and describe its distribution and movement.

Groundwater represents the largest reservoir of freshwater that is readily available to humans. Groundwater is an equalizer of stream flow, and the dissolving action of groundwater produces caverns and sinkholes. - Groundwater is water that occupies pore spaces in sediment and rock in a zone beneath the surface called the zone of saturation. -

Oxbow lake

It's called this because of the shape of the lake

A cross-sectional view of a stream from head to mouth is a _____________ profile.

Longitudinal

Compare and contrast springs, wells, and artesian systems.

Springs occur where the water table intersects the land surface and a natural flow of groundwater results. -Wells, which are openings bored into the zone of saturation, withdraw groundwater and may create roughly conical depressions in the water table known as cones of depression -Aretisan wells tap into inclined aquifiers bounded above and below by aquitards.

Gradient

The slope of a stream channel expressed as the vertical drop of a stream over a specified distance

Hydrologic cycle

The unending circulation of water

Which drainage pattern develops in areas of alternating weak and resistant bedrock?

Trellis Pattern

Capacity is related to discharge. True or False.

True

True or False. Factors that increase downstream are velocity and discharge.

True

True or false, once groundwater is contaminated the problem is very difficult to solve, requiring expensive remediation or simply abandonment of the aquifier.

True

The Yellowstone river is an example of what kind of valley?

V-shaped Valley

List the hydrologic's major reservoirs and describe the different paths that water takes through the hydrolic cycle.

Water moves through the hydrosphere's many reservoirs by evaporating, condensing into clouds, and falling as precipitation. Once it reaches he ground, rain can either soak in, evaporate, be returned to the atmosphere by plant transpiration, or run off. Running water is the most important agent sculpting Earth's varied landscaping

What are three things that shape valleys?

Weathering Overland flow Mass wasting

What are three main parts (zones) of a river system?

Zone of Sediments Zone of Transportation Zone of Deposition

Longitudinal profile

a cross-sectional view of a stream from its source area to its mouth

What separates drainage basins?

a divide

Aquifer

a permeable layer of material

Infiltration

a portion of water sinking into the ground

Aquitard

an impermeable layer of material

Bedrock channels

are cut into solid rock and are most common in headwaters areas where gradients are steep. Rapids and waterfalls are common features

Alluvial channels

are dominated by streamflow through alluvium previously deposited by the stream. A floodplain usually covers the valley floor, with the river meandering or moving through braided channels

Evapotranspiration

both evaporation and transpiration involve the transfer of water from the surface

Dissolve load

brought to a stream by groundwater and is dispersed throughout the flow

Caverns

chamber in a cave

Sinkholes

irregular terrain punctuated with many depressions

Karst topography

is a landscape formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves.

Competence

is a measure of a stream's ability to transport particles based on size rather than quanity

Capacity

is the maximum load of solid particles a stream can transport per unit of time

Settling velocity

it defined as the speed at which a particle falls through a still fluid

Drainage basin

land area that contributes water to a river system

Where is the stream energy directed from when it comes to wide valleys?

side to side

Laminar flow

slow-moving streams that move in straight line paths that are parallel to the stream channel

Bed load

stream load of solid material consists of sediment that is too large to be carried in suspension

Braided channel

streams that have an interwoven appearance and a large portion of the stream's loadcconsists of coarse material (sand and gravel)

Evaporation

the process by which liquid water changes into water vapor (gas), is how water enters the atmosphere from the ocean and from the continent.

runoff

the surplus water flows over the surface into lakes and streams

What is the water table?

the upper limit of the zone of saturation

Discharge

the volume of water flowing past a certain point in a given unit of time

As generalization, river systems tend to erode at the ____________ end, transport sediment through the middle section, and deposit sediment at the _________ end.

upstream, downstream

Turbulent flow

water moving in an erratic fashion that can be characterized as a swirling motion

transpiration

water that's soaked into the ground, absorbed by plants, wich is then released into he atmosphere

Suspended load

where most streams carry the largest part of their load and has a muddy appearance