Grading

==Expressing slope==
===Slope gradient===
Slope gradients are are common form of expression for steeply sloped areas like the sides of swales. Expressed as Y:X where Y is a single unit of rise and X is the corresponding run. It can be calculated by dividing the rise by the run:
e.g.:\frac{rise}{run}=\frac{4\ m}{12\ m}=\frac{1}{3};we\ say\ the\ slope\ =1:3\ or\ 1\ in\ 3
===Slope percentage===
Slope percentage is calculated similarly by dividing rise by run, but then multiplying by 100 to get a percentage:
e.g.:slope=\left (\frac{rise}{run}\right )\times 100=\left(\frac{4\ m}{12\ m}\right)\times 100= 33\%
But for many calculations the rise/run isn't multiplied by 100, and instead is left as a decimal. e.g. 0.33 in the example above.
===Slope in degrees===
Expressing a slope in degrees requires using the tangent trigonometric function. 
e.g.:\tan \theta =\left ( \frac{4\ m}{12\ m} \right ); \theta =\tan^{-1}\left ( 0.33 \right )=18.3^{\circ}
 Quick reference table
==Normal range of slopes==
The Accessibility for Ontarians with Disabilities ActOntario. O. Reg. 191/11: INTEGRATED ACCESSIBILITY STANDARDS, 2011. https://www.ontario.ca/laws/regulation/r11191. provides a bare minimum to which public spaces must be designed. e.g. cross slope not to exceed 2 %. 
Consider designing landscapes to universal design principals insteadUniversal Design.com. 2018. “The Leading Source for News and Information on Universal Design - The Leading Source for News and Information on Universal Design.” 2018. http://www.universaldesign.com/.Institute for Human Centered Design. 2018. “Principles.” 2018. https://www.humancentereddesign.org/inclusive-design/principles.. 
 Grading Standards and Critical GradientsStrom, S., Nathan, K., Woland, J. Site Engineering for Landscape Architects (6th Ed.) 2013, Wiley and Sons
Use 	Extreme range (%)	Desirable range (%)
Public Streets 	0.5 - 10 	1 - 8
Private streets 	0.5 - 20 	1 - 12
Service lanes 	0.5 - 15 	1 - 10
Parking areas 	0.5 - 8 	1 - 5
Parking ramps 	up to 20 	up to 15
Collector walks 	0.5 - 12 	1 - 8
Entrance walks 	0.5 - 8 	1 - 4
Pedestrian ramps 	up to 12 	up to 8
Stairs 	25 - 50 	33 - 50
Game courts 	0.5 - 2 	0.5 - 1.5
Paved gutters 	0.25 - 100 	1 - 50
Grassed swales 	0.5 - 15 	2 - 10
Terraces and sitting areas	0.5 - 3 	1 - 2
Grassed banks 	up to 50 	up to 33
Planted banks 	up to 100 	up to 50
==Freeboard==
==Additional Resources==
*Planning and Design (Huang, 2012)Huang, J. C. 2012. PDH online Course C115 (5 PDH) - Site Planning and Design. UNIFIED FACILITIES CRITERIA (UFC)
SITE PLANNING AND DESIGN. U.S department of Defense. https://wiki.sustainabletechnologies.ca/images/3/39/Huang_2012.pdf
*Grading and Earthwork (Matusik and Deibel, 2004)Matusik, J., and Deibel, D. 2004. Land Development Handbook - CHAPTER 24: Grading and Earthwork. Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com). https://wikidev.sustainabletechnologies.ca/images/d/d7/Matusik_2004.pdf
*Fundamentals of Site Grading Design (Tiner, 2014)Tiner, J. A. 2014. Fundamentals of Site Grading Design. A SunCam online continuing education course. https://wiki.sustainabletechnologies.ca/images/a/a5/Tiner_2014.pdf
*Slope-Meter, Inc. - external resource, Slope Conversion Table (Slope-Meter Inc. 2009)Slope-Meter Inc. 2009. Download Slope Conversion Tables. Copyright 2009 - Slope-Meter Inc. - All Rights Reserved. http://slopemeter.com/images/Slope_Conversion_Tables.xls
==References==
Category: Calculations