Day 1 Finals Flashcards
Zone of greatest Turbulence
Away from the zone of greatest velocity
It is the depressions may be rounded or
sharp, cusped in profile, and have crests lying
across the current path. Also related to separated
Erosional Marks
A process of erosion, ___________ refers to the strictly mechanical wear of bedrock by moving detrital and other materials during (a) their migration downslope under the influence of gravity, and (b) their further transportation by erosional agencies such as running water, moving ice, or wind.
Corrasion
The erosion of weak, cohesive rocks by the force of water in a river
Fluid Stressing
Largest particle size the stream can carry
Competence
Maximum volume of sediments a stream can carry of a given size
Capacity
Transportation of sediment occurs in three ways:
Suspension, Saltation, and
Rolling.
Force that pulls the water downslope
Force of Gravity
Resistance for downslope movement
Frictional Forces
Roughness is controlled by:
Amount of Vegetation
Size of Bed
Bank Material
Irregularity of adjacent channel cross sections
Discharge is expressed as _______________
Discharge is expressed as volume of water
over time where
Q= AV
Q = Discharge
A = Cross Sectional Area
V= Velocity of the flowing water
A graph where Flow volume of water plotted against time
Hydrograph
height of maximum height of the stream over time
Stage Hydrograph
discharge over time
Discharge hydrograph
How to calculate flood return period
𝑟𝑒𝑡𝑢𝑟𝑛𝑝𝑒𝑟𝑖𝑜𝑑= (𝑛𝑢𝑚𝑏𝑒𝑟𝑜𝑓𝑦𝑒𝑎𝑟𝑠+1) / (𝑟𝑎𝑛𝑘𝑜𝑓𝑡ℎ𝑒𝑖𝑛𝑑𝑖𝑣𝑖𝑑𝑢𝑎𝑙𝑓𝑙𝑜𝑜𝑑)
T or F. Bedload increases as flow velocity and discharge increases.
True. Bedload is reported to be
only 1% of the overall sediment
discharge of the river, however 70%
in alpine areas.
Zone where in streams swiftly flow down steep mountain slopes and cut deep, v-shaped valleys. Waterfalls and rapids occur in this zone
Zone 1 Headwaters
Zone where Lower elevation streams merge toflow down on gentle slopes. Valleys broaden as coalescing rivers start to meander
Zone 2 Transfer Zone
Zone at the lowest elevations, a river meanders across a broad, nearly flat valley and floodplain.
Zone 3. Depositional Zone
T or F. If a drainage basin and channel morphology are related to the geologic, climatic and hydrologic character of the basin, it is not necessary describe the features quantitatively in order to investigate these relationships.
F. If a drainage basin and channel morphology are related to the geologic, climatic and hydrologic character of the basin, then it is necessary to describe the features quantitatively in order to investigate these relationships.
What is the second largest river basin in the Philippines, and what is itss total land area
Mindanao River Basin, 21,503 Km^2
What are the 5 Provinces that covers the Mindanao River Basin
Bukidnon, Maguindanao, North Cotabato, South Cotabato, and Sultan Kudarat
what is the largest river in the philippines
Cagayan River
Formula for drainage density
𝐷𝑟𝑎𝑖𝑛𝑎𝑔𝑒𝐷𝑒𝑛𝑠𝑖𝑡𝑦= sum𝐿/𝐴Where:
L= Stream Length
A= Drainage Basin Area
What are the geometrical way to categorized stream order?
Strahler, Horton, Shreve, Hack
states that the number of streams of
different orders in a drainage basin tends closely to approximate an
inverse geometric series in which the first term is the number of
streams of order one.
Law of Stream number
states that the average lengths of the
streams of each of the different orders in a basin closely approximate
a direct geometric series in which the first term is the average length
of streams of the first order.
Law of Stream length
slopes states that slopes of streams of different
orders are related to the stream order by an inverse geometric series
Law of stream slopes
states that the main drainage basin
areas of streams of different orders tends to closely approximate a
direct geometric series in which the first term is the mean area of the
first order basins.
The law of drainage basin area
states that the drainage areas of
streams of each order and the total stream length contained within
and supported by these areas is direct logarithmic function.
The law of contributing areas
direct logarithmic function of the area
of the drainage basin of the stream above the point at which
discharge was measured.
The discharge of a stream is a direct logarithmic function of the area
is an index of the potential energy available in the drainage
basin. The higher the relief the higher the erosional forces acting on
the basin
Relief
Determines the erodibility of the surface
materials, and to some extent the permeability
Lithologic Variations
Gives secondary permeability for fluid flow, and
a primary control for the orientation and drainage pattern of a system
Geologic Structure
Development of stream
pattern on a pristine surface
Initiation
The growth of the channel
into the available area and blocking out
of the network
Elongation
Filling out the network
with lower order tributaries
Elaboration
When drainage
density is the greatest and the network
fills the open spaces
Maximum Extension
loss of identity of the small
order streams with progressive reduction
of drainage density through time
Integration
Most commonly formed on horizontally
bedded and uniform sediments or on
uniformly resistant crystalline rocks.
Dendritic
Usually develops on moderate to steep slopes,
but also where regional structure, such as
outcropping resistant rock bands, are elongated
and parallel. All forms of transition can occur this
type and dendritic and trellis pattern.
Parallel
Patterns most commonly on dipping or folded
sedimentary or weakly metamorphosed sedimentary
rocks; also areas of joints and faults which intersect with
right angles and old sand dunes with parallel alignment
Trellis
Usually have a more or less
perpendicular turns mainly caused by
crisscrossing fractures
Rectangular
Occurs around domes or cones, and
particularly common on volcanic areas
Radial
Patterns also develop around domes, where there exists
alternating resistant and weak beds, so that the major
channels cut through the strike and the low order streams
follow the dip of the rocks.
Annular
Can occur in a variety of conditions where local
hummocks and depressions inhibit a continuous
channel network. Irregular glacial deposits or
erosional hollows due to solution of underlying
lithology, irregular thawing permafrost. Coastal
dunes, delta plains, and wind eroded hollows
Multibasinal
Incised into rocks with complicated structural
patterns. Associated with crystalline metamorphic
rocks with a history of intense folding, jointing,
intrusions, alterations, and faulting.
Contorted
Fluvial sediments are laid down, and depositional landforms are
created at:
- Dominantly or partially subaerial conditions
- Topographic discontinuities
- Valleys and the margin of water bodies
What are the importance of fluvial deposits?
- Sources of groundwater
- Placer deposits
- Conduits for petroleum
- Coal deposits in paleo deltaic environments
All are general conditions of Alluvial fans except;
a. Arid to Semi Arid Environments, Occurs in Fault fronts, Tectonic Mountain Fronts or Sudden Topographic Discontinuities
b. General gradient: 3 6 , Marginal screes: ~30, Near the apex: ~10
c. Large Sediment Supply, Exhibits complex cross bedding, Flow Structures
d. None of the Above
D.