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− | ;m | + | ;A<sub>c</sub> :Area of the catchment, whole contributing drainage area (usually in m<sup>2</sup>). |
− | :run of side slopes in channel cross sections (length, but usually expressed as a ratio in relation to rise. e.g. where side side slopes = 1:3.5, m = 3.5) | |
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− | ;q | + | ;A<sub>p</sub> :Area of the practice e.g. footprint area of a bioretention cell (usually in m<sup>2</sup>) |
− | :infiltration rate in (length per time, usually mm/hr) (before or after application of safety factor?) | |
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− | ;R<sub>a</sub> | + | ;d :Depth e.g. of an infiltration practice (units of length, usually mm or m) |
− | :Existing rise of swale gradient (length, usually m) | |
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− | ;R<sub>b</sub> | + | ;f :Infiltration rate (usually mm/hr) |
− | :Rise of compensation gradient for an enhanced swale (length, usually m) | |
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− | ;SCF | + | ;h :height (units of length) |
− | :Safety correction factor (dimensionless) | + | |
| + | ;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 :Manning's coefficient (unitless) Note: for clarity porosity is being expressed as 'void ratio' and sharing the notation V<sub>R</sub> |
| + | |
| + | ;N :Number of days in the month |
| + | |
| + | ;P :Perimeter of infiltration practice or swale x-section (m) |
| + | |
| + | ;q :Infiltration rate in (length per time, usually mm/hr) |
| + | |
| + | ;q':Infiltration coefficient in (length per time, usually mm/hr) after application of safety correction factor (SCF) |
| + | |
| + | ;Q<sub>p</sub> :Peak flow in units of volume per time (e.g. m<sup>3</sup>/s) |
| + | |
| + | ;R :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. |
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| + | ;R<sub>a</sub> :Existing rise of swale gradient (length, usually m) |
| + | |
| + | ;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 MOECC, 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 :time (usually in hrs) |
| + | |
| + | ;T :Temperature (°C) |
| + | |
| + | ;V :Volume (usually in m<sup>3</sup>) |
| + | |
| + | ;V<sub>R</sub> :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 :Depth of water (L, usually m or sometimes mm) |