A |
= area |
|
= branch of a river |
|
= buoyancy in kN |
|
= cross-section of flow |
|
= runoff during an observed period of time T |
AE0 |
= precipitation area |
|
= total catchment area surface in m² or km² |
Ai |
= partial area of a partial catchment area in m² or km² |
A1,2.. |
= partial area of station 1, 2 . . |
a |
= aerated area between tail water and top of the weir crest |
|
= calibrated parameter for current meter (given by manufacturer of the instrument) |
|
= height of the sluice opening |
|
= inside width between trash rack / sluice bars |
|
= coefficient dependent upon particle diameter |
B, b |
= width of weir, canal |
b |
= calibrated parameter for current meter (given by manufacturer of the instrument) |
|
= width of trash rack / screen |
C |
= concentration of suspended matter |
Cs |
= content of suspended matter |
c |
= correction coefficient |
|
= coefficient of resistance of particles |
D |
= equivalent diameter (4 F / U = 4 ·B ·h / (B +2h)) |
d |
= distance between the trash rack / screen bars |
|
= particle diameter |
E |
= catchment area |
F |
= cross-sectional area |
|
= Froude's number |
Fi |
= individual surface fractions |
fv |
= velocity area |
fvm |
= mean velocity area |
G |
= weight of the structure in kN |
g |
= acceleration due to gravity = 9.81 m/s² |
H |
= horizontal forces |
|
= main stream, main river |
HHQ |
= highest discharge |
HQ |
= flood discharge |
HQ100 |
= 100-yearly flood |
HW |
= high-water level |
h |
= depth of water at the vertical lines of measurement |
|
= elevation of water surface |
|
= impounding head |
|
= water level |
hA |
= runoff rate of the AEO during a certain period of time (T) in mm |
hE |
= energy head |
hN |
= height of precipitation above AEO during a certain period of time (T) in mm |
|
= heavy precipitation |
hR |
= retention rate in the AEO during a certain period of time (T) in mm |
hV |
= evaporation height in the AEO during a certain period of time (T) in mm |
hm |
= mean weir head |
hü |
= weir head |
hüe |
= head of diversion weir |
hüs |
= head of retaining weir |
I |
= slope, gradient |
iN |
= intensify of precipitation in mm/hour |
k |
= correction factor |
kS |
= roughness coefficient |
L |
= length of structure |
|
= length of trash rack / screen |
l |
= length of transition area (sand trap) |
MMQ |
= mean monthly discharges of all years observed |
MQ |
= mean monthly discharges of one year |
MW |
= mean water level |
mG |
= bed load movement |
niG |
= bed load transport |
mGf |
= bed load |
mSf |
= suspended matter load |
rnSf |
= suspended master transport |
N |
= precipitation |
NG |
= area precipitation |
NNW |
= lowest low-water level |
NQ |
= low discharge |
NW |
= low-water level |
Ni |
= precipitation of the station i |
N1,2.. |
= point precipitation of station 1, 2 . . . |
n |
= correction coefficient |
|
= number of events |
|
= number of revolutions per unit of time |
|
= pore volume proportion |
ni |
= number of potential steps in flow direction up to the point i being sought |
nS |
= number of potential lines |
|
= number of potential steps |
o |
= index for headwater |
PG |
= bed load pressure |
PSi |
= seepage water pressure at a specific point i |
Pu |
= tail water pressure |
Q |
= discharge |
QA |
= discharge in the branch of a river |
|
= design discharge |
QH |
= discharge in the main river |
Qü |
= discharge capacity over the weir |
R |
= retention in the catchment area during T (interception, infiltration) |
Re |
' = Reynolds' number |
rhy |
= hydraulic radius |
S |
= seepage water pressure |
s |
= height of end sill |
|
= length of measurement section |
|
= density of particles due to density of water |
T |
= time, unit of time |
|
= recurrence interval |
TK |
= time of concentration in hours |
TN |
= duration of precipitation |
TR |
= duration of precipitation |
t |
= water depth |
tan j |
= friction coefficient |
td |
= time of passage |
ts |
= settling time, sinking time |
U |
= wetted perimeter |
|
= tail water pressure |
u |
= index for tail water |
V |
= evaporation above the catchment area during T |
|
= vertical forces |
VQ |
= estimated discharge |
v |
= flow velocity |
vA |
= flow velocity in the diversion canal |
vE |
= flow velocity in, the settling basin |
vz |
= flow velocity in the inlet canal |
vd |
= flow velocity in the settling basin |
vi |
= individual velocity values |
vm |
= mean flow velocity |
vS |
= settling/sinking velocity of particles |
vS' |
= mean settling/sinking velocity of particles |
WG |
= height of the amount of bed load |
WH |
= horizontal water pressure |
WH1e |
= horizontal water pressure in the headwater |
WHr |
= horizontal water pressure in the tail water |
WV |
= water surcharge on the structure |
We |
= height of diversion weir |
WS |
= height of retaining weir |
w |
= weir crest height |
|
= dynamic buoyancy due to turbulent flow |
x |
= calibration factor |
a |
= angle of curvature / bend |
|
= velocity coefficient |
b |
= angle of inclination |
gF |
= specific weight of solid matter particles |
gG |
= specific weight of bed load |
gS |
= specific weight of particles / grains |
gW |
= specific weight of water |
D |
= difference |
DZel |
= difference of energy heads |
d |
= contraction coefficient |
m |
= discharge coefficient |
|
= weir coefficient |
mX |
= reduced weir coefficient |
j |
= retardation coefficient |
n |
= kinematic viscosity of the water |
nG |
= stability against sliding |
y |
= runoff coefficient, discharge coefficient |
l |
= loss coefficient |