Running Water Flashcards
1
Q
Importance of running water
A
- movement and transport for people/materials
- irrigation
- energy production
- sediment transport
- life in general
2
Q
what is the hydrologic cycle a summary of
A
the circulation of earth’s water supply
3
Q
what are the processes involved in the hydrologic cycle
A
- precipitation
- evaporation
- infiltration
- runoff
- transpiration
4
Q
what are the 3 largest sources of water
A
- oceans
- ice sheets
- groundwater
5
Q
what are 8 major stream parts
A
- head
- course
- mouth
- reach
- bed
- banks
- longitudinal profile
- gradient
6
Q
1
A
source (head)
7
Q
2
A
tributary
8
Q
3
A
confluence
9
Q
4
A
river
10
Q
5
A
levee
11
Q
6
A
delta
12
Q
8
A
mouth
13
Q
9
A
channel
14
Q
10
A
oxbow lake
15
Q
11
A
meander
16
Q
mouth is where
A
the stream ends in WATER BODY
17
Q
the head is also known as the
A
source area
18
Q
what is the head
A
where water originates at high gradient streams
19
Q
what is the river course
A
the river path
20
Q
what is the river’s reach
A
segment of a stream
21
Q
what is a rivers longitudinal profile
A
the side view of the stream
22
Q
what is the gradient of a river
A
slope of longitudinal profile
23
Q
what does running water begin as
A
sheet flow
24
Q
what is a sheet flow’s infiltration into groundwater controlled by
A
- intensity and duration of rainfall
- prior wetted conditions of soil
- soil texture
- slope of land
- natura of vegetative cover
25
what does sheet flow develop into
tiny channels called rills
26
how much of total precipitation runs off as overland flow and becomes stream flow
25 to 40 %
27
what does overland flow become
stream flow
28
what are the sources of stream flow
1. overland flow
2. base flow
29
where is the rest of stream flow coming from besides overland flow
base flow (from groundwater discharge)
30
what are drainage networks
includes all the stream channels that drain toward a reference point but is bound by a divide
31
what is a divide for drainage basins
the imaginary line separating one basin from another
32
what is a drainage basin
land area that contributes water to the stream
33
does streams share a drainage basin
NO - each stream has its own
34
what is stream order
a numerical system used to classify streams and rivers based on their size and branching patterns
35
what does a stream order of 1 compared to 3 mean
1: smallest tributaries (more frequent)
3: largest tributaries (longer in length)
36
three types of streams
1. perennial
2. ephemeral
3. intermittent
37
perennial streams
permanent steams that carry water all year round
38
compare water table to base of perennial stream
water table is ABOVE the base of lake AT ALL TIMES
39
what type of stream is this
Perennial streams
40
what are the two types of temporary streams
1. intermittent
2. ephemeral
41
ephemeral streams
streams that carry water during WET season or during/after rainfall
42
do ephemeral streams have water on the surface
NO - dry on surface but running water underground
43
type of stream
ephemeral stream
44
type of stream
intermittent stream
45
intermittent stream
flows for only PART of the year
46
four types of stream channel patterns
1. straight channels
2. sinuous channels
3. meandering channels
4. braided streams
47
straight channels
short and uncommon channels that indicate strong control by the underlying geologic structure
48
are straight channels generally young or old
young
49
sinuous channels
more common and found in almost every type of topographic setting
50
what is the uncommon type of stream channel
straight channels
51
what is the more common stream channel
sinuous channel
52
what is the preferred shape of a stream channel
sinuous
53
meandering channels
intricate pattern of smooth curves where the stream follows serpentine course
54
what type of land usually forms meandering channels
flat ground
55
braided streams
a multiplicity of inter-woven and interconnected channels separated by low bars (islands) of sand, gravel
56
type of stream channel
straight channel
57
type of stream channel
meandering (sinuous)
58
type of stream channel
braided
59
two main drainage patterns
discordant and concordant
60
2 types of discordant drainage patterns
1. superimposed
2. antecedent drainage
61
concordant drainage patterns
1. consequent streams
2. subsequent streams
3. resequent streams
4. obsequent streams
62
discordant drainage
does not correlate to the topography and geology of the area
63
describe the river in discordant drainage
it follows its initial and not affected by changes in topography
64
superimposed vs antecedent drainage patterns
superimposed
- on top of the topography so the original drainage pattern becomes incised into underlying rock
antecedent
- drainage pattern interrupted by uplift so slowly that the stream is able to maintain its previous established course
65
what type of discordant drainage cuts through newly formed landforms and maintains the same path
antecedent
66
what type of discordant drainage has no relation with harder rock bed
superimposed
67
is a superimposed stream younger or older than the topography they flow through
younger
68
are antecedent streams younger or older than the topography they flow through
older
69
type of discordant drainage
superimposed
70
type of discordant drainage
antecedent
71
what is the first stream to develop in concordant drainage
consequent stream
72
concordant drainage
correlates to the topology and geology of the area
73
what type of drainage pattern has the path of the river highly dependent on the slope of river and topography
concordant drainage
74
what is the most commonly found drainage pattern
concordant
75
describe the consequent stream course
original course follows the regional slope of the topography
76
what stream is also known as dip streams
consequent streams
77
subsequent stream
develop along zones of structural weakness (at right angles)
78
what type of rock does a subsequent stream form
on non-resistant rock (soft rock)
79
do subsequent streams form before or after the main stream has been established
AFTER
80
resequent stream
flows in the same direction as initial consequent drainage
81
are resequent older or younger than the initial consequent drainage
OLDER
82
what angle do resequent streams enter a consequent stream at
acute angle
83
what angle do subsequent streams enter the consequent stream
90 angles
84
obsequent streams
develop after the valley development of consequent and subsequent rivers
85
what do obsequent streams form right angles with
subsequent streams
86
what direction do obsequent streams flow compared to original consequent river
OPPOSITE flow
87
1
Consequent River
88
2
Resequent
89
3
Subsequent river
90
4
Obsequent River
91
types of drainage patterns (9)
1. dendritic
2. parallel
3. trellis
4. rectangular
5. radial
6. centrifugal (centipedal)
7. annular
8. multibasinal
9. contorted (deranged)
92
cause of deranged drainage pattern
blocking of old drainage by till or moraines
93
causes of dendrite drainage pattern
no structural control (sediments are flat lying or posses homogenous lithology)
94
causes of parallel drainage pattern
pronounced slope or structural controls (hard vs soft rock)
95
causes of trellis drainage pattern
tilted or folded alternating hard and soft sedimentary rocks
96
causes of annular drainage pattern
dome in alternating hard and soft sedimentary rocks
97
causes of rectangular drainage pattern
joint or fault control in homogeneous strata
98
causes of radial drainage pattern
volcanic cones (domes in homogeneous strata)
99
form of deranged drainage pattern
drainage not coordinated (has numerous local drainage basins and lakes)
100
form of dendrite drainage pattern
random pattern of branching and integrated streams
101
form of parallel drainage pattern
regularly spaced in parallel streams
102
form of annular drainage pattern
circular drainage pattern linked by one radial stream
103
form of rectangular drainage pattern
drainage in two directions at RIGHT ANGLES
104
form of radial drainage pattern
streams radiating out from common center
105
most common drainage pattern
dendritic
106
what does dendritic drainage pattern look like
tree
107
what kind of bedrock does a dendritic pattern form
no restrictions to geology or topography with uniform underlying bedrock
108
were is water flowing in parallel pattern
regions of soft rock
109
what type of region forms a parallel stream pattern
parallel elongated landforms with a slope to the surface
110
what links trellis pattern
long parallel streams are linked by short right angle segments
111
type of strata supporting trellis pattern
bands of alternating tilted soft and hard strata
112
what regions are rectangular patterns found
have undergone faulting
113
does a stream follow the path of least resistance
YES
114
where are rectangular patterns concentrated
in places where the exposed rock is WEAKEST
115
where does a radial pattern form
form at a concentric UPLIFT (topographic HIGH)
116
what can form a radial pattern
isolated volcano
117
does a radial pattern have drainage in one direction
NO - has it in all directions
118
what is the opposite drainage pattern as a radial pattern
centrifugal or centipedal
119
where do centrifugal patterns form
topographic LOW
120
what are centrifugal patterns associated with
streams converging in a basin
121
where does an annular pattern develop on
a dome or basin (topographic HIGH or LOW)
122
what does a multibasinal pattern reflect
hummocky glacial deposits (kame and kettle) , karst or permafrost regions
123
what does deranged pattern develop from
the disruption of a pre-existing drainage pattern
124
where is the grade of a stream the steepest
headwaters
125
where is the grade of a stream the most flat
mouth
126
what can the upper course gradient be for a stream
5m/km
127
what can the middle course gradient be for a stream
1.67 m/km
128
what can the lower course gradient be for a stream
1 m/km
129
what is the average gradient for a stream
2 m/km
130
what is valley deepening
stream expends most energy in down cutting
131
what type of valley will a young stream form
a V-shape valley
132
how does base level affect reshaping a valley
its the lowest level or limit the stream will down cut a valley
133
what is the limiting factor for valley downcutting
the river's base level
134
where does the base level of a river extend from
underneath the continents from sea level to coast
135
what is a graded stream
a stream which the gradient just allows the stream to transport its load
136
does base level cutting down expend energy out or down
OUT
137
is movement for a graded stream lateral or down
lateral
138
is valley deepening expending energy down or lateral
down
139
where does knickpoint form
where a stream flows over a resistant layer of rock
140
what is a knickpoint associated with
a sudden change in the slope of a river profile
141
what is common at a knickpoint
waterfalls and rapids
142
how does a knickpoint migrate back up the river
when the water flows over the lip over time the hard rock will wear down and the knickpoint collapses and a new one forms upstream
143
what processes take place in valley widening
combined action of weathering, mass wasting and overland flow
144
what is lateral erosion
the erosion that takes place as a stream flows from side to side
145
what stream development often shows lateral erosion
mature streams
146
two ways valley lengthening can happen
1. headward erosion
2. delta formation
147
what is headward erosion
the river erodes in an upstream direction,
148
what topography will have more headward erosion
steeper slopes
149
what are two consequences of headward erosion
1. stream capture
2. elbow capture
150
contrast stream capture with elbow capture
stream capture
- a portion of a stream basin is diverted by headward erosion into ANOTHER basin
elbow capture
- abrupt bend in the stream channel where the capture took place
151
how do rivers form deltas
when a valley lengthens seaward by deposition
152
two types of base levels
1. ultimate (Sea level)
2. local or temporary
153
what is the ultimate base level
sea level
154
what does raising base level result in
deposition
155
what does lowering river base level cause
erosion
156
what determines the type of stream flow
velocity
157
two types of stream flow
1. laminar
2. turbulent
158
factors that determine stream velocity
1. gradient/slope
2. channel traits (shape, size and roughness)
159
does a steeper gradient have more or less velocity
more
160
does a wider or narrow stream have faster velocity
wider
161
what is laminar flow also known as
streamline flow
162
where is laminar flow found
in the middle of river
163
does laminar flow travel smoothly
YES
164
is laminar flow interrupted
NO
165
what type of flow forms eddies
turbulent flow
166
1
laminar flow
167
2
turbulant
168
turbulent flow
fluid flow involving irregular fluctuations or mixing
169
what type of river flow forms murky water
turbulent flow
170
describe the speed of turbulent flow
continuously changing in both direction and magnitude
171
what causes the turbulent streams to have changing magnitude and directions
friction and channel irregularities
172
what is channel flow confined to
channels
173
what is the fastest flow in the river
thalweg
174
where is the thalweg found in river
in the middle of the course
175
what are the factors that affect velocity of water flow
1. gradient
2. channel shape
3. channel size
4. channel roughness
5. discharge
176
what is gradient
the drop in vertical elevation of the stream's surface for a horizontal distance
177
how does steeper gradient relate to velocity
more velocity and stream energy
178
what is discharge
the volume of water moving past a given point in a certain amount of time
179
does a cross section of a stream change over the course of a river
YES
180
how does a larger cross sectional area relate to velocity
HIGHER velocity
181
how does lower perimeter affect velocity
less friction which means HIGHER velocity
182
how does smoother channel affect velocity
HIGHER velocity
183
formular for calculating velocity of streams
184
factors that increase downstream
velocity
discharge
channel size
185
what does a meander cause on the river shoreline
as it pushes out on a curve it causes erosion which causes mass movements
186
factors that decrease downstream
1. gradient
2. channel roughness
187
why does discharge increase downstream
because tributaries are progressively feeding water into the main channel
188
formular for river discharge
velocity x cross sectional area
189
what happens as discharge of a river increases
1. channel width increases
2. velocity increases
3. depth increases
190
does frictional drag increases downstream or upstream
downstream
191
what is sheet erosion
water flowing across the surface as a thin sheet and transporting materials loosed by splash erosion
192
is sheet water penetrating the ground
NO
193
how do rills causes erosion
by increase in volume and turbulence causing erosion of fine grain sediments
194
what do rills form as they grow
gullies
195
movement of water towards a stream
precipitation ----> sheet -----> rills -----> gullies ---> stream
196
what are methods of stream erosion
1. attrition
2. abrasion
3. solution
197
do stronger currents lift particles more or less effectively
more
198
what is the relation with larger particles and erosion
larger particles need higher velocity of river to erode
199
is it easier for a stream to transport smaller or larger particles
smaller
200
stream erosion as attrition
suspended rocks collide and break up
201
how is attrition different from abrasion
abrasion is at the river bed and attrition is NOT
202
stream erosion as solution
dissolving of materials into the water
203
A
attrition
204
B
Abrasion
205
C
Solution
206
what is a stream's load
transported material in the river
207
types of loads
1. dissolved
2. suspended
3. bed
208
what is river capacity
max load a stream can transport
209
does capacity refer to only two of the loads or all
all of the loads
210
what load is the first to be deposited
bed load
211
what is dissolved load
earth material that has been dissolved into ions and carried in solution
212
5 ions that make up most of the dissolved load
1. chloride
2. sulphate
3. bicarbonate
4. sodium
5. calcium
213
when is the river at max concentration (dissolved load)
during low discharge conditions when groundwater is the MAIN source of flow
214
what does a high suspended load mean
muddy water
215
suspended load
sediment particles that are mechanically transported by suspension within a stream or river
216
examples of suspended load
clay and silt
217
what size particles are in a suspended load
very small particles
218
bed load
discharge of sediment particles that are too heavy to be suspended by the flow
219
how do particles in bed load move
rolling, sliding and skipping along stream bed
220
competence t
the max particle SIZE a stream can transport
221
what determines a stream's competence
the velocity
222
1
dissolved load
223
2
suspended load
224
3
bed load
225
competence vs capacity
competence
- measure of particle size a stream can transport
capacity
- measure of the amount of solid material a stream can transport
226
what determines streams competence
velocity
227
what determines stream's capacity
discharge
228
what happens when competence reduces
sediments begin to drop out with big sediments deposited first
229
what is alluvium
stream sediments
230
channel deposits 3
1. bars
2. braided streams
3. deltas
231
flood plain deposits
1. natural levees
2. back swamps
3. yazoo tributary
4. alluvial fans
232
what are bars
elevated region of finer grained deposited by the river flow
233
most typical bar
point bar
234
type of channel deposition
point bar
235
where are point bars most common
meandering rivers
236
where are mouth bars most common
river deltas
237
what are braided streams
multi-thread channels that branch and merge to create the characteristics braided pattern
238
what kind of gradient forms a braided stream
gentle gradient
239
where are delta deposits located
at the mouth of a stream entering a body of standing water
240
how are deltas formed
the sediment load carried by a stream is deposited because of a sudden REDUCTION in stream velocity
241
two parts of a delta
subaqueous and subaerial
242
contrast the two parts of a delta
subaqueous
underwater part that is the steepest slopped with the finest material
subaerial
above the water
243
what forms natural levees
overflowing of channel banks and the rapid decrease in velocity
244
where are natural levees found
deposits parallel to the stream channel
245
what is the purpose of natural levees
keep water in the channel so they are natural flood protections
246
what floodplain deposit is this
natural levee
247
what are back swamps
area of low, ill drained ground on a flood-plain away from the main channel
248
are backswamps above or below natural levees
below
249
yazoo tributary
a tributary stream running parallel to the main river
250
what angle does a yazoo tributary stream enter the main stream
acute angle
251
alluvial fans develop where
a high gradient stream leaves a narrow valley
252
what floodplain deposit is this
alluvial fan
253
most common landform on earth's surface
stream valley
254
two types of stream valley
1. narrow valley
2. wide valley
255
narrow vs wide stream valley
narrow
- v shaped
- downcutting toward base level
- has features including waterfalls and rapids
YOUNG RIVERS
wide
- OLD STREAMS
- stream near base level
- erosion is lateral NOT downward
- forms floodplains
256
what are incised meanders
meanders in steep, narrow valleys
257
what causes incised meanders
INCREASED EROSION CAUSED BY
1. uplift of the region
2. drop in base level
258
what is a remnant of a former floodplain
stream terraces
259
what forms stream terraces
when a river has adjusted to a relative drop in base level by downcutting
260
types of floodplains
1. erosional
2. depositional
261
types of meanders
1. cut bank and point bar
2. cutoffs and oxbow lake
262
what is a floodplain
flat area of land next to a river or stream that stretches from banks of river to outer edge of valley
263
what is the area that floods during a flood
floodplain
264
where do floodplains often form
where a meandering stream flows across a wide nearly level valley floor
265
two parts of a floodplain
1. floodways
2. flood fringe
266
contrast the different parts of a flood plain
floodways
- main channel of the river
flood fringe
- extends from outer banks of floodway to bluff lines
bluff lines
- mark the area where the valley floor begins to rise
267
erosional vs depositional floodplain
erosional
- younger streams ABOVE the base level
depositional
- older streams when the base level RISES
268
three stages of stream development
youth
mature
old
269
what kind of erosion does young rivers have
headward erosion
270
profile of young rivers
steep irregular profile
271
characteristics of young rivers
waterfalls
rapids
plunge pool
272
shape of young river
v-shape
273
what stage does the river start to widen
mature
274
type of erosion of mature streams
lateral erosion
275
what shape does a mature stream have
meandering stream
276
characteristics of mature stream
1. flood plain with prominent valley walls
2. braided channel
3. sand bars
277
compare old river to its base level
at or around its base level
278
shape of old age river
channel is wide and u shaped
279
describe the load of the river
finer materials
280
is discharge at max for old rivers
yes
281
features of fold river
deltas
natural levees
oxbow lake
282
processes of young rivers
1. headward erosion
2. downcutting
283
mature stream processes
1. lateral erosion
284
old age stream processes
1. deposition
2. poor drainage
285
davis geomorphic cycle
cycle of erosion with river stages (young, mature, old, rejuvenated)
286
cutoff meander
loop is short-circuited as a stream cuts a new channel across its neck and starts meandering again
287
most common geologic hazard
floods
288
causes of floods
natural from too much precipitation
human induced by dam failures
289
types of floods (4)
1. regional floods
2. flash floods
3. ice jam floods
4. dam failure floods
290
what causes regional floods
precipitation that cannot enter absorbed
291
what is the effect of regional floods
affects a large geographic area that can cause wide property damage and death
292
when do regional floods occur
on seasonal basis when precipitation overfills basin and floods the bank
293
largest flood type
regional floods
294
flash flood area
small areas
295
when do flash floods occur
within 6 hours of heavy rainfall
296
how do ice jam floods occur
when chunks of ice clump together to block the flow of a river
297
what causes a ice jam flood
melting snow and ice in spring
298
dam failure floods
uncontrolled release of water from a reservoir through a dam as a result of structural failures
299
what happened in the st francis dam
a mass movement (slump) on an older scar into the dam displaced a large volume of water and the pressure broke the dam
300
what are some flood controls
1. artificial levees
2. flood control dam
3. channelization
301
what is an artificial levee
an artificial wall that blocks the water from going where isnt wanted
302
what type of material forms an artificial levee
impermeable material so water doesn't wash it away
303
channelization
widening or deepening a river to increase its capacity for flow volume
304
1
alluvial deposits
305
2
bluffs
306
3
yazoo tributary
307
4
meandering scar
308
5
meandering stream
309
6
oxbow lake
310
7
meander scar
311
8
cutoff
312
9
point bar
313
10
backswamp
314
blank at bottom
natural levees
