FLOOD

Question 1

Described as the volume of water moving
through a channel over a given time interval,
commonly measured in units such as cubic
feet per second (ft 3 /s)

Answer 1

Stream Discharge

Question 2

to drain water off the landscape and to transport sediment

Answer 2

role of streams

Question 3

a process where water flows through
stream channels

Answer 3

Runoff

Question 4

precipitation reaching the land
surface moves downslope in thin sheets

Answer 4

Overland Flow

Question 5

discharge of
groundwater into the surface environment

Answer 5

Groundwater baseflow

Question 6

provide information about a
river or stream by simply plotting the discharge versus
time

Answer 6

Stream hydrographs

Question 7

are a result of less deep infiltration in
arid areas resulting in a water table that is below the
level of most stream channels

Answer 7

Losing streams

Question 8

are generally small and relatively fast
moving and occupy narrow valleys, but then evolve

Answer 8

Headwater streams

Question 9

Individual systems are separated from one another by a
topographic high or crest in the landscape called a

Answer 9

drainage divide

Question 10

represents the land area that collects water for an
individual stream or river.

Answer 10

drainage basin

Question 11

are any smaller streams that feed larger streams within a
drainage basin

Answer 11

Tributaries

Question 12

A method of classifying or
ordering the hierarchy of
natural channels

Answer 12

Strahler Stream Order

Question 13

reflects downstream trade off between discharge
and slope in setting transport capacity (and thus ability to move
sediment and incise rock)

Answer 13

Longitudinal Profile

Question 14

The
level below which a river or stream cannot incise

Answer 14

Base Level

Question 15

Most commonly formed on horizontally
bedded and uniform sediments or on
uniformly resistant crystalline rocks.

Answer 15

Dendritic

Question 16

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

Answer 16

Parallel

Question 17

Patterns most commonly on dipping or folded
sedimentary or weakly metamorphosed
sedimentary rocks; also areas of joints and

Answer 17

Trellis

Question 18

Usually have a more or less
perpendicular turns mainly
caused by criss crossing
fractures.

Answer 18

Rectangular

Question 19

Occurs around domes or cones, and
particularly common on volcanic areas.

Answer 19

Radial

Question 20

Patterns also develop around domes, where
there exists alternating resistant and weak
beds, so that the major channels cut through

Answer 20

Annular

Question 21

Can occur in a variety of conditions where local
hummocks and depressions inhibit a continuous
channel network.

Answer 21

Multibasinal

Question 22

Incised into rocks with complicated structural
patterns. Associated with crystalline metamorphic
rocks with a history of intense folding, jointing,
intrusions, alterations, and faulting.

Answer 22

Contorted

Question 23

all year agas na river

Answer 23

perennial

Question 24

mo agas lang during heavy rain

Answer 24

ephemeral

Question 25

naay month range para mo agas ni na river

Answer 25

intermittent

Question 26

are loose rock particles/sediments
deposited on a stream.

Answer 26

Alluvium

Question 27

One of the key factors in a stream’s ability
to erode the landscape is the

Answer 27

velocity of
the water

Question 28

are unstable overhang located
at the outer bank which is produced by the
velocity increase on the outer bank which
subsequently enhances the ability of the
water to cut (erode) into the bank.

Answer 28


Cutbanks

Question 29

On the inner bank where velocity decreases,
sediment tends to accumulate and form a
deposit known as a

Answer 29

point bar

Question 30

the sediment that physically scrapes
or wears away rock in a process called

Answer 30

abrasion

Question 31

Evidence for stream abrasion in solid rock can be seen in

Answer 31

potholes

Question 32

The velocity of a particular stream segment is controlled
by the steepness of the channel, called

Answer 32

stream
gradient

Question 33

is used to describe the lowest
level to which a stream can erode

Answer 33

base level

Question 34

often referred to as ultimate base level
because the oceans represent the end or low point of
most rivers (exceptions include isolated areas below sea
level, such as the Dead Sea and Death Valley)

Answer 34

Sea level

Question 35

describes the fraction of solid particles that is
in a suspended state and moving at the same velocity as the
water suspended material is what makes streams appear
muddy

Answer 35

Suspended load

Question 36

The process whereby water separates sediment grains based
on their size, shape, and density is called

Answer 36

called hydraulic sorting

Question 37

are mound shaped channel deposits consisting of sorted material ranging in size from boulders to
coarse gravel to fine sand.

Answer 37

Bars

Question 38

develop on the inside of meander bends where water velocity
decreases.

Answer 38

point bars

Question 39

are formed when a river enters a lake or ocean and splits into smaller channels and begins to
deposit sediment due to a decrease in velocity.

Answer 39

Deltas

Question 40

are large fan shaped deposits that form where steep mountain streams empty
out onto valley floors at the mouth of rivers.

Answer 40

Alluvial fans

Question 41

Streams also transport considerable amounts of dissolved ions (charged atoms) in what scientists refer to as the

Answer 41

dissolved load

Question 42

produces wider valleys over time, whereas deposition on the
inner
banks helps to build a flat plain on the valley floor called a

Answer 42

natural floodplain.

Question 43

are pair of ridges that run parallel to the bank
which are formed due to the deposition of sediment, commonly
sand, at the edge of the bank.

Answer 43

Natural levees

Question 44

are areas on the floodplain that are poorly
drained and can remain wet long after a flood.

Answer 44

Back swamps

Question 45

are old floodplain left high and dry as river
migrates.

Answer 45

Stream terraces

Question 46

The potential for flooding in a given area naturally increases as the_________ and _______ of rainfall
increases. Rainfall events range from light, steady rains that may last for days to heavy, and torrential rains

Answer 46

intensity and duration

Question 47

The ability of the ground to absorb water, referred to as

Answer 47

infiltration capacity,

Question 48

are floods that have short duration
with relatively high peak discharge; small
streams and rivers tend to rapidly overflow
their banks.

Answer 48

Flash Floods

Question 49

can be defined as one where a river
leaves its channel farther down in its drainage
basin, flowing out onto its floodplain and
inundating large areas of the valley floor.

Answer 49

Downstream Floods

Question 50

normally dry areas of
the land become inundated

Answer 50

flood

Question 51

the height at which a river
begins to overflow its banks.

Answer 51

Flood stage

Question 52

straightening and deepening a stream channel

Answer 52

Channelization

Question 53

temporarily stores some the excesses water in a
series of depressions

Answer 53

Retention Basins

Question 54

type of barrier in which
vegetated strips line the banks of stream channels,

Answer 54

Stream buffers

Question 55

made of a synthetic
fabric that is fi ne enough to trap sediment,

Answer 55

silt fences,

Question 56

Wetlands (swamps) are commonly found in
topographic depressions and adjacent to river channels, in
which case they are called

Answer 56

riparian wetlands

Question 57

Large pipes called _____ are typically used
for small streams that flow intermittently.

Answer 57

culverts