Unit 3 Learning Check NFIP Flashcards
as directed by the national flood insurance act of 1968, FEMA conducts flood studies in order to determine __ and ___
floodprone areas
flood risk zones
the base flood is a flood that has a ___ risk of occurring in any year
1% chance
the base flood is also called the ___ year flood
100
True or False: a 100 year flood will occur only once every 100 years
false
True or False: a 100 year flood could occur two times in a year
true
True or False: the 100 year flood might not occur in a 200 year period
true
True or False: the base flood could occur two consecutive years in a row
true
on NFIP maps, the 100 year floodplain is called the ____
special flood hazard area
BFE is the acronym for
base flood elevation
what are the components of a flood insurance study
FIS - flood insurance study report
FIRM - flood insurance rate map
the flood boundary and flood way map - included in studies prepared before 1986 (after 1986, floodway shown on FIRM)
for purposes of a riverine flood study, ___ is the study of the distribution and circulation of water in the environment, and ____ is the study of fluids in motion and how water with flow through the channel
hydrology
hydraulics
the rate at which runoff flows downstream is called the flood ___
discharge
what probable effect does an increase in urbanization within a community or upstream of it have on the stream discharges within that community
stream discharges usually will increase as a consequence to the increase in urbanization within the community or upstream of it
what consequence of flood water level of a stream would usually occur when the bridge is constructed over a stream
a hydraulic analysis is always required to determine the effect of any bridge construction over a stream. however, construction over a stream is considered an obstruction to the food and therefore may increase flood water level upstream of the construction
to locate the true elevations at a site, surveyors have established ___ marks also known as ____ marks
elevation reference
bench
cross sections describe the ___ of the floodplain
shape
what is the datum used for your communities flood insurance study, FIRM, and profile
check legend or key to FIRM
flood profiles are developed by plotting the flood elevations at the ___ and connecting the plotted points
cross sections
to make a floodplain map, the base flood elevations are plotted ona ___ map or a ____ map
topographic
contour
the ___ is defined as the stream channel and that portion of the adjacent floodplain that must remain open to permit passage of the base flood
floodway
a floodway analysis conducted to the minimum NFIP standard allows the fringe to be obstructed until the base flood level is increased by how much?
1 foot
what causes a storm surge
storms that bring air pressure changes and strong winds that pile water up against the shore
what is wave runup
when waves hit the shore, water moved with such force that it keeps traveling inland higher than the still water flood level
instead of cross sections, coastal flood engineers survey __
transects
the BFE for coastal studies are the ___ plus the ___
stillwater elevations
wave runup
the most hazardous part of the coastal floodplain is the ____ area, which is shown on the map as a ___
coastal high hazard area
V
what differentiates shallow flooding from riverine flooding
shallow is different from riverine or coastal because it occurs in areas where there is no channel or identifiable flow path
flood studies that do not identify BFE are called __
approximate studies
prior to 1986, the maps published with an FIS are the ___ and the ___. since 1986, the map published with an FIS are the ___
old format FIRM, or FHBM, or floodway map
new format FIRM
FIRM map - flat or z fold
what does an elevation reference mark look like on a FIRM
locations are identified with a small x and the designation ERM or RM followed by a number
what is an AO zone
area subject to sheet flood, ponding, or shallow flooding
what is the FIRM effective date for your community
date of the first FIRM for your community
the date determines whether building is pre FIRM or post FIRM
how is a floodway shown on the flood boundary and floodway map
it is the white area adjacent to and including the channel
how is a floodway shown on the new format FIRM
shaded areas with diagonal lines
a zone C on an old format FIRM is shown as a zone ___ on the new format FIRM
zone X
CBRA is an acronym for what
coastal barriers resource act
what communities floodplains are shown on the countrywide FIRM
all the communities in the country, even those not currently in the NFIP
floodways are shown along the ___ toe of a levee on the FIRM
landslide
areas behind recognized levees are designated as
shaded zone X
the base flood elevation is the elevation of the ___ year flood or the ___ % annual chance flood
100
1
the special flood hazard area or SFHA is how the ___ floodplain is shown on FEMA maps
base flood
the SFHA is shown on a FIRM as a zone that begins with the letter __ or __
A
V
what are the components of a flood insurance study
flood insurance study report
flood insurance rate map
flood boundary and floodway map for studies pre 1986. after 1986, floodway is on FIRM and no separate maps
___ is the study of the watershed behaviour during and after a storm
hydrology
surveyors reference elevation to a common
datum
most permanent FIS elevatoin reference marks are referenced to what datum
national geodetic vertical datum (NVGD)
a hydraulic study uses hydrology, cross section information, and stream characteristics to determine the flood
elevations (and velocities and floodplain widths)
cross sections are shown on which map
floodway map - new format FRIM
flood profiles are used to determine what
flood elevations along a river or stream between cross sections
in riverine situations, the floodplain is divided into two separate parts for the floodplain management purposes. these parts are ___ and ___
floodway
flood fringe
based on the minimum NFIP standard, if the flood fringe were completely filled, how high could the base flood elevation go up
1 foot
what FIRM zone has wave heights greater than 3 feet
V zone
instead of using a base flood elevation, some shallow flooding areas are defined use a base flood ___
depth
an approximate study shows the base ___ but does not show the base flood ___
floodplain
elevation
how many digits are there in the NFIP community identification number
6 digits
FIRM has 5 digit county wide
community identification number does not include panel number and other numbers near it on the FIRM title block
what is an AH zone
shallow flooding base floodplain with base flood elevations
what was the problem with the way the floodway was shown on the old format flood boundary and floodway maps
white area looked like it was a C zone outside of the floodplain. if people only had FIRM, they did not know of the floodway hazard
the new format FIRM includes
floodways and floodplain management information
simplified flood insurance management information
simplified flood insurance zones
do Q3 flood data show base flood elevations if available
no. they primarily determine if a property is in or out of the SFHA
