Difference between revisions of "Notation"

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;A<sub>c</sub>
;A<sub>c</sub> :Area of the catchment, whole contributing drainage area (usually in m<sup>2</sup>).
:Area of the catchment, whole contributing drainage area (usually in m<sup>2</sup>).  


;A<sub>p</sub>
;A<sub>i</sub> :Area of impervious cover within the catchment (usually in m<sup>2</sup>)
:Area of the practice e.g. footprint area of a bioretention cell (usually in m<sup>2</sup>)


;d
;A<sub>p</sub> :Area of the practice e.g. footprint area of a bioretention cell (usually in m<sup>2</sup>)
:Depth e.g. of an infiltration practice (units of length, usually m)


;h
;D :Duration of the design storm event (in units of time, usually hrs)
:height (units of length)


;L
;d<sub>p</sub> :Surface ponding depth of an infiltration practice (unit of length, usually mm or cm)
:Length, e.g. of a reach, channel or swale (usually in m)


;m
;d<sub>m</sub> :Filter media depth of a bioretention, stormwater planter or soil cell practice (unit of length, usually mm or cm)
:run of side slopes in channel cross sections (length, but usually expressed as a ratio in relation to rise. e.g. side slopes = 1:3, so m = 3)


;n
;d<sub>s</sub> :Storage reservoir depth of an infiltration practice (unit of length, usually mm or cm)
:Manning's coefficient (unitless) Note: for clarity porosity is being expressed as 'void ratio' and sharing the notation V<sub>R</sub>


;P
;d<sub>T</sub> :Total depth of an infiltration practice (unit of length, usually cm or m)
:Perimeter of infiltration practice or swale x-section (m)


;q
;f :Infiltration rate, measured (usually mm/hr)
:Infiltration rate in (length per time, usually mm/hr)


;q'
;f':Design infiltration rate (length per time, usually mm/hr) after application of safety correction factor (SCF)
:Infiltration coefficient in (length per time, usually mm/hr) after application of safety correction factor (SCF)


;Q<sub>p</sub>
;h :Height (units of length)
:Peak flow in units of volume per time (e.g. m<sup>3</sup>/s)


;R
;i :Intensity of the design storm event (in units of depth/time, usually mm/hr)
:Ratio of catchment (A<sub>c</sub>) to the practice footprint area (A<sub>p</sub>). ''syn.'' I/P ratio. For [[green roofs]] (and often permeable paving systems) this will be 1:1. In [[bioretention]] it may be 15 or 20 to 1. 


;R<sub>a</sub>
;i :Thornthwaite monthly heat index (-)
:Existing rise of swale gradient (length, usually m)


;R<sub>b</sub>
;I :Thornthwaite annual heat index (-)
:Rise of compensation gradient for an enhanced swale (length, usually m)


;RVC<sub>T</sub>
;L :Length, e.g. of a reach, channel or swale (usually in m)
:Runoff volume control target (as outlined by MOECC, units are mm)


;S<sub>0</sub>
;m :Run of side slopes in channel cross sections (length, but usually expressed as a ratio in relation to rise. e.g. side slopes = 1:3, so m = 3)
:Longitudinal slope (m/m, i.e. dimensionless)


;S<sub>x</sub>
;n :Porosity, applies to aggregate and other void-forming materials, filter media and native soils (unit is vol/vol, so dimensionless)
:Cross slope (m/m, i.e. dimensionless)


;SCF
;n :Manning's coefficient (unitless) Note: the symbol n is also used for porosity so it is important to be sure which term is implied.
:Safety correction factor (dimensionless)


;t
;N :Number of days in the month
:time (usually in hrs)


;V
;Q<sub>p</sub> :Peak flow in units of volume per time (e.g. m<sup>3</sup>/s)
:Volume (usually in m<sup>3</sup>)


;V<sub>R</sub>
;R :Ratio of catchment impervious area (A<sub>i</sub>) to the practice permeable footprint area (A<sub>p</sub>). ''syn.'' I/P ratio. For [[green roofs]] and often [[permeable pavements|permeable pavement]] systems that do not receive drainage from external impervious areas this will be 0. For [[bioretention]], [[infiltration trenches]] and [[infiltration chambers]] receiving pavement runoff, it is recommended to be kept between 15 to 20.
:Void ratio, as usually applied to aggregates and yard materials. In this guide, it is also applied to native soils in lieu of porosity (unit for both are vol/vol, i.e. dimensionless)


;y
;R<sub>a</sub> :Existing rise of swale gradient (length, usually m)
:Depth of water (length, usually m or sometimes mm)
 
;R<sub>b</sub> :Rise of compensation gradient for an enhanced swale (length, usually m)
 
;RVC<sub>T</sub> :Runoff volume control target (as outlined by MECP, units are mm)
 
;S<sub>0</sub> :Longitudinal slope (m/m, i.e. dimensionless)
 
;S<sub>T</sub> :Storage (m<sup>3</sup>)
 
;S<sub>x</sub> :Cross slope (m/m, i.e. dimensionless)
 
;SCF :Safety correction factor (dimensionless)
 
;t :Drainage time (usually in hrs)
 
;T :Temperature (°C)
 
;V :Volume (usually in m<sup>3</sup>)
 
;x :Perimeter of infiltration practice or swale x-section (m)
 
;y :Depth of water (L, usually m or sometimes mm)

Latest revision as of 18:32, 6 August 2020

Ac
Area of the catchment, whole contributing drainage area (usually in m2).
Ai
Area of impervious cover within the catchment (usually in m2).
Ap
Area of the practice e.g. footprint area of a bioretention cell (usually in m2)
D
Duration of the design storm event (in units of time, usually hrs)
dp
Surface ponding depth of an infiltration practice (unit of length, usually mm or cm)
dm
Filter media depth of a bioretention, stormwater planter or soil cell practice (unit of length, usually mm or cm)
ds
Storage reservoir depth of an infiltration practice (unit of length, usually mm or cm)
dT
Total depth of an infiltration practice (unit of length, usually cm or m)
f
Infiltration rate, measured (usually mm/hr)
f'
Design infiltration rate (length per time, usually mm/hr) after application of safety correction factor (SCF)
h
Height (units of length)
i
Intensity of the design storm event (in units of depth/time, usually mm/hr)
i
Thornthwaite monthly heat index (-)
I
Thornthwaite annual heat index (-)
L
Length, e.g. of a reach, channel or swale (usually in m)
m
Run of side slopes in channel cross sections (length, but usually expressed as a ratio in relation to rise. e.g. side slopes = 1:3, so m = 3)
n
Porosity, applies to aggregate and other void-forming materials, filter media and native soils (unit is vol/vol, so dimensionless)
n
Manning's coefficient (unitless) Note: the symbol n is also used for porosity so it is important to be sure which term is implied.
N
Number of days in the month
Qp
Peak flow in units of volume per time (e.g. m3/s)
R
Ratio of catchment impervious area (Ai) to the practice permeable footprint area (Ap). syn. I/P ratio. For green roofs and often permeable pavement systems that do not receive drainage from external impervious areas this will be 0. For bioretention, infiltration trenches and infiltration chambers receiving pavement runoff, it is recommended to be kept between 15 to 20.
Ra
Existing rise of swale gradient (length, usually m)
Rb
Rise of compensation gradient for an enhanced swale (length, usually m)
RVCT
Runoff volume control target (as outlined by MECP, units are mm)
S0
Longitudinal slope (m/m, i.e. dimensionless)
ST
Storage (m3)
Sx
Cross slope (m/m, i.e. dimensionless)
SCF
Safety correction factor (dimensionless)
t
Drainage time (usually in hrs)
T
Temperature (°C)
V
Volume (usually in m3)
x
Perimeter of infiltration practice or swale x-section (m)
y
Depth of water (L, usually m or sometimes mm)