HEC RAS Flashcards
if top is flow what must bottom boundray be
stage hydrograph of tide to restrain water levels
other boundry conditions for water
rating curve
time series of gate openings
what is a rating curve
discharge vs stage
boundary conditions for sediment transport
bed gradation
load equilibrium
rating curve (sed load to load)`
what three changes d you want to get cross sections at
geometry changes
hydraulic structures
flow changes
four modelling types
flood waves-DAMBRK
water quality-QUAL2e
water profile-Hec_RAS
habitat modelling _PHABSIM
two eautions and the assumnptions for HEC RAS in findinw ater profile
cons mass
cons momentum
incompressibke
boittom slope small
flow parralle to bottom slope
what are 6 reasons why it will be unstable
1 large changes in water levels 2. large time step with different n's 3 bad Bc's (two flows) 4 incomplete geometry 5 transition sub super sub 6 hydraulic structures too small
how many dimensions for hec
1d
name of equation it is based on
st venant
2 indepedatn and 2 dependent
inde- x and t
dep
Q and h
example of steady
quasi steady
and unsteady
steady-flood plain management
quasi steady- sedimet
transient-model storage, seasonl changes
