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139 Cards in this Set

  • Front
  • Back
What are the relative percentages of water found in each of the planet’s geophysical reservoirs (oceans, groundwater, surface water, ice). Be able to rank them
Oceans – 97%
Ice – 2%
Groundwater - .29%
Other Sources - .02%

Other sources:

Freshwater Lakes
Saline Lakes
Soil Moisture
Water Vapor
What are the terms of the water balance equation? Be able to quantify the water balance if given data for some of the terms.
Change in S = P – (R + I + ET). Change in S equals Precipitation – Runoff + infiltration + evapo transpiration
What is the distinction between evaporation and transpiration? What are the conditions when transpiration is/is not applicable.
Evaporation is from a body of water – transpiration is from trees/plants. Transpiration will not occur in areas where there is little vegetation
How are Wild and Scenic Rivers different from other rivers? What are the special characteristics?
Must be in a free-flowing condition and must be deemed to have one or more “outstandingly remarkable” scenic, recreational, geologic, fish and wildlife, historic, cultural or other similar values.
What are the distinguishing features of Wild versus Scenic versus Recreational Rivers?
Wild – free of impoundments, generally inaccessible, primitive watersheds
Scenic – free of impoundments, accessible by roads, primitive watersheds
Recreational – readily accessible by road or railroad, some development along shore, may have had some impoundments or diversion in past
How many rivers were inaugurated into the system in 1968?
What is conveyed on the hydrograph and discharge rating curves (i.e., what is plotted on each axis)?
Discharge rating curve – y axis has Stage (ft) and x axis has discharge (cfs)

Hydrograph – y axis has Q (discharge) and x axis has time (t)
What is the purpose of the discharge rating curve (why is it used?)
Discharge rating curve provides the unique relationship between the measured stage and the deduced discharge at a certain point (makes it so you don’t have to take velocity measurements once discharge rating is known.)
What is the sequence of steps necessary for the creation of a discharge rating curve. How do you go about creating one?
Discharge rating curve is developed by performing many stream discharge measurements and simultaneously noting the stage
Know the meaning of stage
Water height in certain, set portion of channel
What is the equation used to compute stream discharge?
Q = Av
What is the two depths to which velocity measurements must be averaged to produce a vertically-averaged velocity (in deep streams).
20% and 80%
How does water velocity tend to change vertically and horizontally across a stream. Where is the fastest water in a stream? The slowest?
Fastest tends to be in the center of the channel – towards the surface and gradually gets slower as you go deeper and/or towards the banks
Cirque Glacier
glaciers that reside in basins or amphitheaters near ridge crests – most have a circular shape
Alpine Glacier
(mountain glacier) glacier that is surrounded by surrounding mountain terrain Valley Glacier – mountain glacier whose flow is confined by valley walls
Tidewater fjord
mountain glacier that terminates in the ocean
Piedmont Glacier
large ice lobe that spreads out over surrounding terrain – associated with terminus of large mountain glacier
Relative sized of glaciers from largest to smallest
Valley glacier (tidewater and piedmont), mountain/alpine glacier, cirque glacier
What are the names and locations of the world’s three ice sheets.
Eastern Antarctic Ice Sheet - Antarctica
West Antarctic Ice Sheet - Antarctica
Greenland Ice Sheet - Greenland
What are the two ways in which glaciers may move. Which way is more common?
Deformation (creep) – movement within individual ice crystals which are subjected to increasingly higher stresses from weight of overlying snow and ice. This is more common way. Other way is basal sliding – meltwater at base of glacier acts as a lubricant enabling glacier to slide across its bed
What is ablation?
ablation is the loss of mass from a glacier. Occurs at base of glacier via melting or calving
What are the processes responsible for mass balance in a glacier?
Ablation, accumulation, sublimation. Accumulation is the addition of mass to a glacier. Occurs at top of glacier via snowfall. Mass balance is the measure of change in total mass of a glacier during a year
What is meant by the equilibrium line on a glacier. What occurs uphill and
downhill of this equilibrium line?
line on glacier that separates accumulation area (uphill) from ablation area (downhill) – marks level on glacier where net loss equals net gain
What is glacial retreat and advance—what enables it to happen?
Glacier retreat occurs when more material ablates from the terminus than is replenished by flow into that region. If a glacier's terminus moves forward faster than it melts, the net result is advance
Understand what is meant by firn, and the steps necessary for the formation of glacial ice.
Rounded, well-bonded snow that is older than one year and has a density of 550 kg/m3
Needs to further compact to become so dense it is impermeable to air at which time it becomes glacial ice.
What is meant by a crevasse. What causes them?
Open fissure in glacier surface caused by tension from deeper part of glacier moving faster and more fluidly than surface
What is plucking?
Plucking is when a glacier freezes to loose bedrock and then picks it up and carries it when it moves downhill.
What is calving?
Calving is when ice breaks off at the glaciers terminus – usually term used for glaciers that terminate in water but can also be used for glacial material that falls from hanging glacier
Know the different cross-sectional shapes for canyons eroded by glaciers versus rivers.
Glaciers form a U shaped canyon while rivers form a V shaped canyon
Know what creates a hanging valley.
A hanging valley is a tributary valley with the floor at a higher relief than the main channel into which it flows. They are most commonly associated with U-shaped valleys when a tributary glacier flows into a glacier of larger volume. The main glacier erodes a deep U-shaped valley with nearly vertical sides while the tributary glacier, with a smaller volume of ice, makes a shallower U-shaped valley. Since the surfaces of the glaciers were originally at the same elevation, the shallower valley appears to be ‘hanging’ above the main valley
Understand why glacial sediment is poorly-sorted, as opposed to well-sorted fluvial sediment, across a longitudinal profile of a drainage basin .
As the glacier flows over the bedrock's fractured surface, it softens and lifts blocks of rock that are brought into the ice. This process is known as plucking, This way, sediments of all sizes become part of the glacier's load. When the glacier melts it leaves behind everything it has picked up
What was the name of the lake in the Megaflood video?
Lake Missoula in Montana
What transient feature was along the shore of lake Missoula?
a Glacier
What evidence exists for the outburst flood in Montana?
Enormous potholes, erratics, hanging valleys, ripple marks, sediment deposits
Have a relative idea of the stream discharge during the outburst flood. Was it as large as
the present-day Mississippi River? The Congo? The Amazon?
The peak flow of the flood was larger than every river in the world flowing simultaneously.
Where on Earth do glacial outburst floods presently occur with some regularity?
What is another name for a glacial outburst flood?
What is the difference between perennial and ephemeral streams.
Perennial streams – flow year round
Ephemeral Streams – only flow part of the year
What is a basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean.
What is a watershed
watershed is an area or ridge of land that separates waters flowing to different rivers, basins, or seas.
What is a (drainage) divide
The border of a drainage basin. The boundary separating adjacent drainage.
What is a confluence
the junction of two rivers
What is a tributary
A river or stream flowing into a larger river or lake.
What is a trunk stream
The trunk stream is defined as the highest order stream that runs through the basin
What is an alluvial fan
area where sediments are deposited (aggredation) on more level terrain at the end of a river valley
What is a delta
area where river water enters ocean and deposits its sediment load
What is an oxbow
water filled former meander that was detached from the main channel in a stream valley.
What is a levee (natural or artificial)
ridge that develops or is situated along the channel of a stream that contains the stream during flood stage
base level
lowest level at which a stream can no longer lower its bed because it flows into an ocean, a lake or another stream
What are the 3 types of sediment load carried by a stream.
Dissolved – mineral ions that are dissolved and carried in solution
Suspended – sediment that floats along in the stream
Bed – larger sediments that are rolled/bounced along channel bed via saltation process
What is meant by a graded stream. What is the evolution of a landscape
when there is a graded stream?
A graded stream is a stream that is capable of transporting the average sediment load provided to it over time. Landscape has reached equilibrium when there is a graded stream
Why do streams meander across a floodplain.
Streams start to meander/erode horizontally once they have reached a graded condition based on slight curvature in the landscape.
As slope increases, what happens to the stream velocity?
As slope increases, stream velocity increases
Do we find meandering streams in mountainous environments?
Why or why not?
Streams don’t meander in mountainous environments because they are not graded
Why do streams get more sinuous with time? And what makes them straighten out?
Over time a stream becomes more graded. It slows down and looses its ability to keep sediments suspended – drops its sediment load, starts to meander. Gets wider at outside of its curves due to changes in velocity of water eroding sediments on the outside curves and depositing them on the inside curves
Identify the inner and outer banks of a meandering stream, state whether erosion or
deposition occurs at each, and where the cut banks and point bars occur.
water erodes sediments on the outside curves/banks (cut banks) and deposits them on the inside curves (point bars)
Why do oxbow lakes and meander scars form?
The meander gets so narrow that during a flood event the water takes the path of least resistance and cuts a new path through the narrowest part of the meander.
Be able to categorize fluvial landforms as erosional or depositional.
Erosional: Ravine, peak, rills, gully, saddle, canyon, spur

Depositional: alluvial fans, flood plains
What are the natural environments in which we tend to find braided streams ? Why do they form?
They form when a river has a high bedload and a low velocity. Usually form in lower, wider river valleys (not at headwaters).
What are the four types of geological conditions that commonly lead to large
Cap Rock – layers of harder rock less subject to erosion forms a resistant layer
Rock Dam – underground intrustion of hard rock covered by softer strata – hard rock gets exposed, forms waterfall
Fault – river encounters a fault, drops inside and scours ot debris
Hanging Valley – formed by a drastic steepening of drainage basin terrain by severe glacial erosion
Understand the difference between steady/unsteady and uniform/nonuniform flow.
Steady refers to flow over time
Uniform refers to rate of flow in a particular space
What are the three types of energy that flowing water may possess, expressing each as a type
of head. How are these related to the hydraulic head? What are the units?
Pressure head, velocity head and elevation head – collectively referred to as the hydraulic head
Understand the meaning of the head loss term hL—what does it physically represent?
Represents energy loss (head is energy) – when it looses some of that energy there is a head loss. Could be lost to friction, sound, heat, etc.
What is the purpose of the Reynolds number—what does it tell us?
Reynolds number is used to distinguish between laminar, transitional and turbulent flows
Re= inertial forces/viscous forces
What is the purpose of the Froude number—what does it tell us?
Froude number is used to determine whether the velocities will be supercritical or subcritical
Fr = inertial forces/gravitational forces
Know the instances in which alpha () is equal to 1 or 1.486.
Alpha is in equations for Mannings discharge – 1 for metric units and 1.486 for English Units
What is the formula for slope
slope is rise/run but can also be determined using the manning equation
What is the formula for hydraulic radius.
Hydraulic radius is area/wetted perimeter (A/P) and is represented by an R
What is the meaning of the wetted perimeter
“Wet” portion of the perimeter of a channel
Understand what factors contribute to the roughness of a stream, and how it is parameterized in Manning’s equations.
?Not sure on answer? Factors are sinuousity, depth, vegetation, boulders, brush, steepness of banks, slope. It is parameterized in Mannings equation by looking at the hydraulic radius, the channel size and the Chezy coefficient which takes into consideration channel slope and bottom roughness
What are the thresholds for whether the Reynolds number represents laminar, transitional, or turbulent flow conditions.
<500 is laminar, 500-2000 is Transitional, >2000 is Turbulent
What Froude number represents, subcritical, critical, or supercritical conditions.
<1 is subcritical, 1 is critical and >1 is supercritical
What is the practical, in-the-field technique for judging whether flow is supercritical or subcritical.
Supercritical flow doesn’t have any ripple patterns behind an obstacle. Subcritical flow does have ripple patterns behind an obstacle
Be able to recognize the open channel formulae describing specific energy and hydraulic head. How are they related to one another? What are their units?
Specific energy is the hydraulic head for open channel flow when referenced in respect to streambed. They are represented in Units of Length.
Understand the meaning of the terms alternate depths for open channel flow, and how they are related to the specific energy.
Depths are supercritical (shallower) or subcritical (deeper/normal) – 2 geometric configurations that will give you specific energy – shallow and fast or deep and slow.
What is hydraulic drop?
Hydraulic drop is transition between subcritical and supercritical flow (From deep to shallow).
What is hydraulic jump?
Hydraulic jump is the transition between supercritical and subcritical flow (from shallow to deep)
What are the six classes of whitewater, if the flow characteristics
are described to you.
I Easy – Fast moving water with riffles and small waves, few obstructions

II Medium – Straightforward rapids with wide, clear channels which are evident without scouting. Rocks and medium sized waves that are easily missed

III Difficult – Rapids with moderate, irregular waves which may be difficult to avoid and which can swamp an open canoe

IV Very difficult Intense, powerful but predictable rapids requiring precise boat handling in turbulent water

V Extremely Difficult Extremely long, obstructed or very violent rapids which expose a paddler to added risk. Drops with unavoidable waves and holes or steep, congested chutes with complex demanding routes

VI Unrunnable These runs have almost never been attempted and often exemplify the extremes of difficult, unpredicatability and danger
What are the ten hydrologic regions of California on a state map.
North Coast Region (Northwest coast)
Sacramento, San Joaquin and Tulare Lake Hydrologic Region (Central valley to N. CA)
San Francisco Bay and Central Coast Hydrologic Region
North and South Lahontan Region – eastern portion of CA near border
South Coast Region
Colorado Desert Region – South Eastern portion of the state
What are the names and locations of the four largest California rivers (based on average annual runoff) in California
Sacramento River, Klamath River, San Joaquin River, Eel River
Name the great lakes
Lake Superior
Lake Michigan
Lake Huron
Lake Erie
Lake Ontario
Braided stream
low flow, through lots of sediment in the streambed
Dendritic stream
like a tree
Distributary stream
splitting apart
Parallel stream
running in parallel branches – usually down a steep hill
Anabranching stream
splitting apart then rejoining
Reticulate stream
many separate branches all flowing the same direction
Radial stream
radiating outward
Centripetal stream
flowing inward – like crater lake
bifurcation ratio for a river system
Number of segments in a given order/Number of segments in next highest order
longitudinal profile for a stream
Longitudinal profile of stream describes the way in which the stream’s elevation changes over distance. X axis represents the distance along a stream, y axis represents elevation
Strahler stream orders
first order streams get ones, when two streams of the same order come together the resulting segment is given the next higher number
Shreve stream orders
first order streams get ones. When two streams of any order come together the resulting segment is the sum of the two previous stream order numbers
first order streams get twos. When two streams of any order come together the resulting segment is log2 of the sum of the two previous stream order numbers. (Or you can multiply the shreve number by two and take the log2)
upstream (flash) flood
Upstream floods – flash floods, caused but lots of water being dropped/running off at once. Quick, violent discharge (that is actually lower Q than downstream flood). Usually happens upstream where there is steep terrain. Upstream floods are more dangerous
Downstream Floods
caused by too much water and high ground saturation. Slow, less violent surge (higher Q than upstream flood). Usually happens in downstream, flatter areas. Downstrean floods create more property damage
glacial outburst flood (jokulhlaup [yo-kul-hloip])
A glacial outburst flood is a flood caused by the failure of a natural ice dam. It would be considered an upstream flood because it produces a fast violent discharge and it usually happens upstream in steep mountain terrain
Be able to distinguish an upstream and downstream floods on a hydrograph
Flash flood is a big spike with a short time and a rapid drop off. Downstream flood is a gradual building that lasts a long time and then slowly declines
n-year flood
An n-year flood means that the probability of having a flood of that magnitude is one in n number of years
Understand the inverse relationship between annual probability of flood, and the flood recurrence interval (return period).
A recurrence interval (return period) of a flood is the average time between flood events that are of equal or greater magnitude. The annual probability of a flood is the inverse of the return period (1/return period). For example, a 100 year flood has an annual probability of .01
Recurrence interval/return period
Recurrence interval/return period is the time between events of a given magnitude, e.g. annual flood, 50 year flood, 100 year flood
Recurrence interval formula
is R = (N + 1) / M where N is the number of years of record and M is the rank of the individual flow with the recorded years (from highest to lowest)
Flood frequency graph
Flood frequency graph y axis is discharge, x-axis is recurrence interval/return period
Water Year
. Water Year starts October 1st of a given year and ends September 30th of the following year. It is identified as the year that it ends in
Be able to compute a discharge anomaly.
Anomaly is the actual discharge minus the average discharge (the difference). An anomaly can be a negative number
Identify the date of the start of spring
The spring runoff starts the day after the lowest point of the anomaly curve
the multiple purposes of damming
- flood control – be able to control stage and release
- water supply – urban water
- power
- agricultural irrigation
- upstream navigation
- Habitat
- Recreation
Upstream problems with Dams
flooding by backwaters
Downstream problems with dams
– impassible for fish
- loss of sediment delivery
o Sediment useful for nutrients
o Useful to prevent net loss to erosion
- Loss of useful flooding
o Flushing salts
o Oxidizing water
- Natural variability is removed (movement of large boulders and trees)
4 different types of dam architectures.
Gravity concrete dam
Gravity concrete dam with buttresses
Concrete arch dam (apex faces toward water)
Earthen embankment dam
Unimpared means free of dams or other impoundments that disrupt or alter the flow of water
what portion of river miles
in the U.S. is unimpared
9% of US River Miles Unimpared
Give the names and positions of the two dams and reservoirs on the lower Colorado
River (framing the Grand Canyon).
Glen Canyon Dam – at top of Canyon
Hoover Dam – below canyon
why the Age of Dams has passed in the United States
- Already a shit ton of dams built
- Part of reason for age of dams was to create jobs during great depression
-Construction of dams was embraced with patriotic enthusiasm – once the goals were reached it lost its excitement
Cite the names of the three most powerful dams in the United States
Grand Coulee
John Day
Cite the names of the three most powerful dams internationally
Itaipu, Brazil-Paraguay
Guri (Raul Leoni), Venezuela
Sayano-Shushensk USSR
What happened at the St. Francis Dam?
St. Francis Dam failed catastrophically, killing hundreds of people
What is channelization? What are the characteristics of a channelized stream?
Channelization is the straightening, deepening, widening, clearing and/or lining existing stream channels. Channelized streams are straight, with increased water temp, no shading, reduced leaf material input, unsorted gravels, reduction in animals and habitat, with fast velocity at high flow and insufficient depth at low flow.
Explain how flood protection on one segment of a river can lead to increased flood risk
on another. For example, on the Mississippi River, how do the flood control efforts of
one state affect another state?
Floodwalls on a river can produce a bottleneck effect – the floodwater is forced through a narrow channel between the flood walls and cause it to back up waiting to get through causing upstream flooding. In 1993 there was flooding in Missouri because of flood protections in place in Mississippi
Understand how the altered sediment deposition due to stream channelization is
responsible for land subsidence. What is the implication of subsidence for the
susceptibility to flooding?
There is less sediment deposited during flood events due to channelization. The lack of new sediments being deposited causes the ground to subside. The implication is that if the land is lower then it is more susceptible to flooding.
Understand the structural insurance and construction regulations for living within
No one is allowed to construct in a 2 year flood plain, if you construct in a 100 year flood plain you must have flood insurance, must have elevated floors that put living portion of the structure more than 1 foot above 100 year flood water line.
What does damming have to do with methylmercury poisoning?
? Naturally occurring mercury becomes methylmercury when land is flooded and vegetation decays. The toxin bioaccumulates in fish and then poisons the people that eat the fish
What political step was significant in halting the Great Whale Project?
New York Mayor Mario Cuomo canceled the states $17 billion electrical contract with Hydro-Quebec
What are the purposes, and the drawbacks, of synthetic flooding in the Grand Canyon?
The purposes were to carry sediment downstream and replenish the beaches along the Colorado river as well as to clear out accumulated debris downstream. The drawback was the loss of millions of dollars in hydropower revenue
What do dams and irrigation have to do with asthma and increased human disease?
Decreased water leads to drops in levels of lakes and rivers. Each year, winds pick up the toxic dust-salt mixture from the dry lake beds and dump them on the surrounding villages and croplands causeing respiratory problems
What is the Colorado River Compact? What is one of its severe shortcomings, as
realized by hydrological and climatological science?
The Colorado river compact was an agreement between all of the states on the Colorado River basin to share the total flow of the river. Each of the states received an entitlement (allocation) based on the total average flow. The severe shortcoming was when they realized that their average flow was calculated during a wet year, and when the climate changed, the same volume of water was no longer available
Understand the geography of the Sacramento-San Joaquin Delta (“the Delta”), and what
water supply, ecological, and economic problems exist with this state water “switchyard.”
Inland region of SF Bay area at confluence of Sacramento and San Joaquin Rivers. Was primarily a tidal wetland interlaced with channels. Currently delta is a water supply for drinking and agriculture, delta has been urbanized, it is diminishing fragile landscape and ecosystem.
What are the range of alternatives for the future of the Delta? Be able to match Delta
alternatives with their descriptions.
Freshwater Delta Alternatives – Putting up levees or leaving existing levees in place – doing whatever is necessary to keep the salt water out

Fluctuating Delta Alternatives – put in aqueducts for freshwater to circumvent saltwater in delta and isolate it so that it can still be used.

Reduced-Exports Alternatives – uses sustainable methods – taking water when it is seasonally opportunistic, managing delta as an ecosystem or abandoning the delta to let it return to its natural environment
What is the California Aqueduct?
California Aqueduct is aqueduct that runs from San Joaquin-Sacramento River Delta down through central California and down into Castaic.
What is the Colorado River Aqueduct
Colorado River Aqueduct is aqueduct that brings water from Colorado river over to Southern California
What is The Los Angeles
Los Angeles Aqueduct is the aqueduct that brings water from Owens valley down to los angeles.
Know the distant water sources for the cities of Los Angeles and San
Distant water sources for Los Angeles is Owens Valley and Colorado River. Distant water source for San Francisco is the Hetch Hetchy River and dam
Who was William Mulholland? For what is he famous, and for what is he infamous?
William Mullholland was the head of the LADWP. He was famous for bringing water in to Los Angeles from Owens Valley via the Los Angeles Aqueduct. He is infamous for building the St. Francis Dam, which failed and killed hundreds of people
How did the City of Los Angeles succeed in acquiring water from such a distant source
as Owens Valley?
William Mulholland bought up land and riparian rights from people who lived along the Owens river. They did it deceptively.
What is the Central Valley Project?
Central Valley Project was a Bureau of Reclamation water project to provide water from Northern California to agricultural areas in the San Joaquin Valley.
What is the LADWP?
The LADWP is the Los Angeles Department of Water and Power. LADWP controls owens valley (LA Aqueduct) water.
What is the The MWD?
The MWD is the Metropolitan Water District. MWD controls Colorado River water.
Peak discharge
when the flood discharge is highest (at its peak flow).
Peak lag time
lag time is the delay between when most rainfall occurs and when the flood happen. Peak lag time is the time at which the discharge is highest (at its peak flow).