Geology
Describe the work of water as it runs across the land. As water runs across the land it: ( Select all that apply.)
(everything except landslides)
During a flood, excess water flows outside of the channel on the adjoining land, which is known as the
Floodplain
The location where a stream stores excess water and sediment during a flood is called a
Floodplain
Describe how crustal uplift can affect the evolution of a fluvial landscape. Crustal uplift will increase the gradient of a drainage basin and lead to stream
Rejuvenation
________ is the type of sediment that is the easiest to erode.
Sand
Which types of sediment(s) require nearly as much water velocity to keep them in motion as is required to erode the grains in the first place?
Sand and Gravel
When headward erosion breaches a drainage divide, intersects another channel, and captures its flow, this is called
Stream piracy
Karst is a geological feature that occurs when groundwater dissolves:
carbonATE rock
Which of the following contributes to desert pavement when found in excessive amounts?
lag deposit
What are the most common ways to recharge groundwater? Groundwater is recharged by: (Select all that apply.)
lakes, streams, wetlands, rainfall
wind is _____ than water
less
What is the density difference between gasoline and water? Where is gasoline likely to collect in an aquifer? Gasoline is ________
less dense
What percentage of streams in the United States are fed by groundwater discharge?
30
The relationship between the number of stream segments in one order and the next is consistently around:
3:1
Water covers how much of the Earth's surface?
71%
What percentage of US freshwater is supplied by water wells?
95
What is another name for a drapery formation in a cave?
A curtain
Which of these sediments has the highest porosity? Which has the highest permeability?
A, A
Which of the following is not one of the unusual features caused by the dissolution process?
ALL ARE
What causes avulsion? Avulsion occurs where a stream _______ its channel and finds a new, more efficient path to base level.
Abandons
______ involves injecting gas (usually air or oxygen) into the saturated zone in order to mobilize contaminants that are volatile or easily stirred into a gaseous phase.
Airsparging
A stream carries a sediment load that may be transported as two types of loads known as
Alluvial Load & Suspended Load
_______ develop(s) when a graded stream incises its floodplain.
Alluvial terraces
a ______ is an underground formation of saturated crust that can produce useful quantities of water when tapped with a well.
Aquifer
Which method of groundwater remediation involves increasing permeability of rock?
Aquifer fracturing
The process that occurs when a flood that has swept down the river arrives at the flat delta plain, overflows its banks, and establishes a new route to the sea is called:
Avulsion
Why is clay difficult to erode but easy to transport?
Because clay sticks to the channel bed but stays in suspension once it has been eroded.
As a field geologist in the area of panel (c), what evidence would convince you that the area once had a waterfall? Evidence would include the presence of
Boulders
Watersheds are shaped roughly like:
Bowls
Well developed permeability channels that form when diffuse-flow aquifers are transformed in conduit-flow aquifers are called?
Conduit systems
What is the difference between a delta and an alluvial fan? Alluvial fans and deltas have similar features ________ from where a stream reaches its base level.
Deltas, Alluvial
Describe how the density of a pollutant governs its role in contaminating groundwater. If a pollutant is denser than water it tends to sink to the bottom of an aquifer; if it is less dense than water it tends to float on top of an aquifer. The
Density
The volume of water (per unit of time) passing any point on a stream is called the
Discharge
________ consists of ions that have entered the water as a result of chemical weathering of rocks.
Dissolved Load
What is the chemical composition of these features? How do they form? Speleothems are usually composed of calcium carbonate that is inorganically precipitated from a dissolved state in groundwater. Precipitation is normally caused by
Evaporation
Increasing the gradient will usually produce a graded stream that successfully transports all the available sediment and does not erode the bed.
FALSE
After a property has been developed with buildings and the land surface paved, the hydrologic character of the runoff stays the same.
False
Clay is relatively easy to erode.
False
How might Darcy's law be useful in planning a program of groundwater conservation? Groundwater can be conserved by removing it at a rate that is more than the rate at which it is discharged. Darcy's Law defines groundwater recharge and provides an estimate of the rate that it can be conserved.
False
Meandering streams are characterized by highly variable discharge, easily eroded banks, and excessive sediment.
False
Most springs are formed in places where the water table is directed away from the surface by the structures of rock layers that contain groundwater.
False
Much of Earth's landscape is the product of erosion caused by wind.
False
Suspended load consists of large particles that remain on the stream bed for most of the time that they are moved by the water.
False
The stream below a dam will experience an decrease in velocity.
False
A stream with no tributaries is known as a:
First-order stream
In arid climates where heavy rains come suddenly, _______ flooding is likely to occur.
Flash
_______ can happen when there are elevated levels of storm water runoff in an arid landscape.
Flash floods
______ originate when hot water in the geyser's plumbing system mixes with cooler water from the surface.
Geysers
What keeps water moving through the hydrologic cycle? Select all that apply.
Gravity, sun, precipitation
Karst formation results from the dissolution of carbon dioxide into
Groundwater
Groundwater that contains high levels of dissolved minerals and often leaves a coating of mineral precipitants on plumbing fixtures is known as
Hard water
What is the name of the diagram that plots the relationship between water velocity and sediment size?
Hjulstorm
The difference in elevation between two points in an aquifer divided by their distance is known as
Hydraulic gradient
Which is true of a sand sea?
It contains many large sand dunes and sand covers more than 20% of the ground surface.
Which of the following is not a characteristic of the Basin and Range Province?
It is an extremely moist desert region.
Water flowing within a channel may be either ______ in which all water molecules travel along parallel and uniform flow paths, or , _____ in which individual water molecules follow irregular paths.
Laminar, Turbulent
Excavations in the ground that are meant to hold waste generated by a community are called
Landfills
Which type of cave is related to the karst process?
Limestone
What is the most extensive cave in the world?
Mammoth
_________ channels are the most common characteristic of a stream that is free to roam across a valley floor.
Meandering
Examples of stream movement that leads to high levels of sediment production do not include:
Meandering Channels
_______ is sometimes seen as "walking away from the problem" of groundwater pollution.
Natural attenuation
What is the effect of momentum on water flow? Momentum keeps water moving in a straight line until some force turns it. This causes erosion on the
Outer
When a meandering stream grows too sinuous so that it is no longer efficient, the stream will find a more direct path from one curve of the stream to the next, cutting off one curve. The body of water formed by the curve that is no longer part of the stream channel is called a(n):
Oxbow lake
_______ is the measure of the ability of rock or sediment to transmit groundwater.
Permeability
______ are closed basins that replace stream valleys and divert surface drainage underground.
Sinkholes
Describe the research program that must have been conducted in order to develop the Hjulstrom diagram. A researcher must have measured the velocity of stream flow that eroded many different
Sizes
Explain why groundwater in karst is highly vulnerable to contamination. Because karst systems are characterized by conduit flow aquifers where water flows rapidly, pollutants enter the system quickly,
Spread
_______ forms from the ceiling of when water drips down through cracks in the cave roof?
Stalactite
What happens when the water table is located beneath the base of a channel?
The channel becomes an effluent stream
Which is not a characteristic of a trade wind desert?
The desert atmosphere accumulates cloud masses.
An artesian aquifer has an internal pressure because of the confining bed that prevents water flow. This pressure is a result of:
The recharge area being at a higher lever than the rest of the aquifer
Which is not a characteristic of crescentic dunes?
The steep slip face is on the convex side of the dune.
Why do the winds at midlatitude deserts tend to be westerlies?
The winds originate at the boundary of the Hadley and Ferrel cells, flow toward the north, and are deflected by the Coriolis effect.
What is unique about the Nile and Colorado rivers that enable them to exist as large desert rivers?
They originate outside of a desert environment and they start in mountains with heavy snow or rainfall.
Braided channels are formed when a stream contains more sediment than it can readily transport.
True
Drainage patterns depend on the nature of the underlying geology.
True
Due to low rainfall, permanent streams are very rare in desert environments.
True
Every point on Earth's surface is part of a watershed.
True
It takes less velocity to keep sediments moving than it does to erode them in the first place.
True
The average velocity of laminar flow is generally greater than turbulent flow.
True
The sediment composing an alluvial fan is subtly sorted so that coarse material tends to be deposited near the mouth of the fan.
True
Water is the dominant agent governing environmental processes.
True
When runoff flows away from a dome or hilltop in all directions it is called radial drainage:
True
Which pathways do water particles follow in turbulent flow? In turbulent flow water particles generally flow downhill but there is locally chaotic water movement in which particles flow against the mean flow direction.
True
Why is flooding described as a "wave"? Stream discharge goes from normal to high and back to normal again as a flood passes. This shape on a graph looks like a wave, and flood comes and goes like a wave with a front, peak, and back.
True
________ flow can keep sediment suspended in the water column longer than ________ flow can, and it increases erosion of the stream bottom and channel walls.
Turbulent, laminar
Porous media in which the grains are not connected to one another are called
Unconsolidated
Two types of erosion that create a valley are
Undercutting and Mass wasting
Waterfalls migrate _________ as resistant rock ledges are eroded:
Upstream
What is the correct formula for the velocity of groundwater flow?
V = K (h2 - h1) / L
The total area feeding water to a stream is called the:
Watershed
Over the next two decades, population growth and increasing demand for freshwater are projected to push all ______ countries into water scarcity conditions.
West Asian
Topset beds constitute the delta plain and are host to freshwater and saltwater _________ if the delta is formed in the ocean.
Wetlands
Which of the following is not one of the three ways that groundwater can interact with wetlands?
Wetlands directly affect the amount of precipitation that accumulates in the atmosphere
What forms when water trickles along the inclined ceiling of a cave?
a curtain
Significant loess deposits are found in the following areas, EXCEPT
africa
Which of the following is characteristic of the Sahel region of North Africa?
all
Which type of atmospheric cell is present in both the northern and southern hemispheres?
all
What characteristics were true of the Sahara between 5,000 and 10,000 years ago?
all are correct
What measures have been implemented nationally to mitigate the threats of desertification?
all are correct
What atmospheric characteristics are present in the formation of polar deserts?
all choices
How are permeability and porosity related to one another? Porosity is an important characteristic that may control permeability. If pores Select your answer the permeability will be high; if they
are connected, are not
What would happen to a parabolic dune if the wind direction changed and precipitation decreased? Parabolic dunes form where sand collects in the lee of vegetation. A decrease in precipitation will likely result in loss of the vegetation. This, plus a reversal in wind direction, will likely produce (Select all that apply.):
barchane, transverse
What is the relationship between regions threatened by desertification and the major deserts we studied earlier? Most areas threatened by desertification
border or lie nearby, deserts
Karst formation involves the dissolution of carbon dioxide into groundwater. Which of the following is the product of this process?
carbonic acid
Many rural and suburban homes are not connected to community sewage disposal lines. Instead they rely on what to dispose of their waste?
cesspools and septic tanks
Fractured aquifers in limestone are most typically caused by:
chemical weathering
Typically, sediments that have high permeability also have high porosity. Which of the following has high porosity, but low permeability?
clay
When cold ocean currents approach land, the heating of _______
cold air
What is a contaminant plume, and how does it move? A contaminant plume is a zone of _________
concentrated
Porous media in which the grains are cemented or compacted are called:
consolidated
Describe the field methods you would use to obtain the data necessary for calculating the discharge in a stream in your neighborhood. Discharge is calculated by collecting data on the
cross sectional, velocity
How do stream gradient and discharge change with distance downstream? Stream gradient ____
decreases, increases
How does the shape of a channel change with distance downstream? A stream channel becomes ________
deeper, wider
What is another name for a gaining stream?
effluent
When openings in bedrock increase in size, and an underground drainage system develops, it is called:
endikarst
Which is harder to erode: gravel or clay?
equally hard
How would you use the law of stream numbers to help manage streams? The Law of Stream Numbers provides a simple guide for
estimating, modeling
Agriculture accounts for 50% of pesticide use in the United States.
false
Collapsing sand comes to rest when it reaches a slope of about 60 to 64 degrees.
false
Hydroelectric dams are great sources of electricity with no downsides.
false
The Indian monsoon is a perennial rain that flows off the Indian Ocean and Arabian Sea.
false
The droughts of the 1930s enabled Utah to become an agricultural, cultural, and political powerhouse.
false
The most common dune is the barchan dune.
false
Water stress problems cannot be solved.
false
When an aquifer is overpumped, a cone of depression decreases the hydraulic gradient.
false
State a hypothesis describing water flow in a channel. Describe how you would test your hypothesis. Hypothesis: Water tends to flow
fastest, deepest
What are the important water problems where you live? An answer should describe: (Select all that apply.)
flooding, polluted, water scarcity
Which attributes are used to identify deserts through the system proposed by the U.S. Geological Survey?
geo location and weather patterns
What force drives the flow of water in the ground? Groundwater flows in response to: (Select all that apply.)
gravity and pressure
Why are stream valleys generally steeper in their upper reaches? How is this related to rainfall or topography? Headwaters are typically located where rainfall is
high, high, high
Which was not a result of the Dust Bowl of the 1930s?
houses were built to create barriers
What are the major processes in the hydrologic cycle? The hydrologic cycle consists of five major processes: (Select all that apply.)
inflitration, runoff, precipitation, condensation, evaporation
What is another name for a losing stream?
influent
What method of remediation involves treating a contaminated aquifer with chemical additives in order to strip or cleanse a specific pollutant?
injection walls
Which factor contributes to the large daily and seasonal temperature range in deserts?
low humidity
What is used in the method of bioremediation to control pollution?
microbes and plant tissue
The extreme interior location of the vast mountainous central Asian deserts contributes to their formation because ________ is lost from the air
moisture
A ______ is a season of high rainfall in the tropics.
monsoon
Develop a hypothesis that predicts the impact of building artificial levees along the Mississippi River and delta. How would this affect downstream communities, the delta region, ecosystems, and coastal waters? Hypothesis: Artificial levees impact natural processes of sedimentation. Along the Mississippi River levees cause ________
more flooding
How many water wells are drilled in the United States each year?
more than 800,000
What measure is being taken to avoid gasoline leaks?
old tanks are being replaced
How does the outer bank of a channel in a curved segment change with time? The outer bank in a meander moves
outward
Which of the following is not a result of global desertification?
ozone depletion
_______ dunes require an abundant supply of sediment and vegetation.
parabolic
What waterways are controlled entirely by rainfall and evaporation?
playa lakes
What is the result of the Coriolis effect on the northern Polar cell?
polar easterlies
Contaminated storm water runoff is referred to as:
polluted RUNOFF
Artesian springs flow because the pressure forces the water out of the ground, and it rises to a new level called:
potentiometric surface
Describe the necessary steps in developing a useful water well. A useful water well begins as a borehole that reaches below the water table. The hole is lined to keep out sediments, the walls of the well are lined with gravel, a
pump, pollution
What is the result of continued condensation across the globe?
rain and snow as well as water droplets and clouds
What forms as windblown grains begin to accumulate?
ripples and dunes
What processes are capable of causing the water table to rise and fall? The water table
rises, fall
The process by which windblown grains move short distances before falling back to the ground is known as
saltation
Which of the following is not one of the four principal types of dunes?
sand seas
If all streams were allowed to flow continuously through time, with no new uplift of the land, eventually they would carve their channels down to
sea level
Are speleothems igneous, sedimentary, or metamorphic? Explain your reasoning. Speleothems are
sedimentary
What factors influence permeability? Permeability is influenced by the
size, connected
In caves, dissolved calcium carbonate in groundwater precipitates on the floor, the roof, or the walls, creating complex "dripstone" features called:
spelothemes
Describe the factors that should be considered in making a decision to allow natural attenuation of a contaminated aquifer. Factors in a decision to allow natural attenuation include: the rate of attenuation, the Select your answer of the contaminant plume (is the plume moving?), is the plume close to sources of Select your answer or natural ecosystems?, the potential Select your answer of clean-up, possibility of disturbing the plume in the event of a massive flood or heavy rainfall event.
stability, drinking water, cost
Identify some potential consequences of an influx of environmental refugees to a village already stressed by desertification. Increased population in an area stressed by desertification can produce more __________
stress
As a consultant you are concerned about future freshwater availability for coastal towns in Florida. What data do you need to assess groundwater resources for the future? State a hypothesis you want to test. Hypothesis: Sea-level rise threatens groundwater in Florida. To assess groundwater resources the following data are needed: maps of the water table , the hydraulic gradient , all cones of depression, the location of the freshwater saltwater transition, rates of sea level rise in the future, and knowledge of whether pumping rates are
sustainable
What region acts as the border between a vast desert and moist tropical rainforests?
the Sahel region of North Africa
Which is not a characteristic of a midlatitude desert?
the rate of moisture condensation exceeds evaporation
Which method of groundwater remediation involves the injection of hot steam?
thermal and electrical treatments
Which of these are characteristics of the top two largest deserts in the world?
they are covered with ice and snow and receive very little precipitation
The interface where freshwater naturally mixes with seawater as it is discharged to the sea is called:
transition zone
An artesian aquifer is one in which water escapes to the surface, driven by the hydraulic gradient of the water table.
true
An ephemeral stream is defined as flowing water present after rainfall events, only containing water for approximately 24 to 48 hours.
true
An erg is what most people imagine when picturing a desert.
true
Coastal deserts are found on continents in both the northern and southern hemispheres.
true
Continued pumping at an excessive rate in coastal areas will cause saltwater intrusion, which damages the quality of the aquifer.
true
Dunes can form underwater in rivers from sand that is transported by running water.
true
Every continent on Earth has significant areas where desertification is an important hazard.
true
Groundwater moves very slowly through relatively impermeable materials such as clay and shale.
true
Millions of livestock and people died as a result of droughts in the Sahel region of North Africa.
true
Natural springs are places where the water table intersects with the Earth's surface and water flows on the land.
true
On April 14, 1935, the worst "black blizzard" occurred, later given the name "Black Sunday."
true
Perhaps you are now concerned with the safety of your drinking water. Describe the steps you will take to allay your concern. Information on the safety of your drinking water can be obtained from your local water board or management agency.
true
Saltation occurs close to the ground with grains that are sand size (0.625-2 mm in diameter).
true
Sand grains are the primary cause of abrasion in the desert.
true
Snow that falls in Antarctica does not go away, but builds up over thousands of years.
true
Some sand dunes cannot be classified, due to their irregular shape.
true
The United Nations believes that local communities are most familiar with their own regions and therefore, should be involved in plan development.
true
The chemistry of water in the ground is capable of causing hydrolysis, dissolution, and oxidation of many minerals.
true
The two largest deserts are covered with water.
true
The westerlies are surface winds in the Ferrel cell moving north and deflecting right across the northern hemisphere.
true
Throughout the Coriolis effect, when air warms it contracts and sinks closer to Earth's surface.
true
Pebbles, cobbles, and boulders with flat wind-abraded surfaces are called
ventifacts
Which, according to the text, is not a factor of desert formation?
warm ocean currents against the tropical coastline
Under what conditions would a stream receive base flow during part of the year but provide recharge at other times? In an area that is dry during one season and wet in another season, and where a stream flows from a distant, wet region, the stream would receive base flow during the
wet, dry
