Changes

[[File:KoppenGeigerclimatezonesCanada_2017.jpg|thumb|Koppen-Geiger Climate Zones of Canada, 2017]]

[[File:KoppenGeigerclimatezonesCanada_2017.jpg|thumb|500px|Koppen-Geiger Climate Zones of Canada, 2017]]

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==Cold climates==

==Cold climates==

The southernmost portion of Ontario has a humid continental climate that features snow and hot summers, with a Koppen-Geiger climate zone classification of "Dfa". Other locations with "Dfa" climate include northern portions of Illinois, Indiana, Iowa and Ohio in the United States.

The southernmost portion of Ontario has a humid continental climate that features snow and hot summers, with a Koppen-Geiger climate zone classification of "Dfa". Other locations with "Dfa" climate include northern portions of Illinois, Indiana, Iowa and Ohio in the United States.

==De-icing salt==

==De-icing [[salt]]==

[[File:Snow_filter_strip.png|thumb|Snow being stored on a filter strip in Markham, ON]]

[[File:Snow_filter_strip.png|thumb|Snow being stored on a filter strip in Markham, ON]]

Sodium and chloride ions in de-icing salts applied to asphalt areas travel easily with the runoff water. De-icing salt can increase the mobility of some [[heavy metals]] in soil (e.g. lead, copper or cadmium). This may increase the downstream concentration of these metals <ref>Amrhein, C., Strong, J.E., and Mosher, P.A. 1992. Effect of de-icing salts on metal and organic matter mobilization in roadside soils. Environmental Science and Technology. Vol. 26, No. 4, pp. 703-709</ref><ref>Bauske, B., Goetz, D. 1993. Effects of de-icing salts on heavy metal mobility. Acta Hydrochimica Hydrobiologica. Vol. 21. pp. 38-42., 1993).</ref>

Sodium and chloride ions in de-icing [[salt|salts]] applied to asphalt areas travel easily with the runoff water. De-icing [[salt]] can increase the mobility of some [[heavy metals]] in soil (e.g. lead, copper or cadmium). This may increase the downstream concentration of these metals <ref>Amrhein, C., Strong, J.E., and Mosher, P.A. 1992. Effect of de-icing salts on metal and organic matter mobilization in roadside soils. Environmental Science and Technology. Vol. 26, No. 4, pp. 703-709</ref><ref>Bauske, B., Goetz, D. 1993. Effects of de-icing salts on heavy metal mobility. Acta Hydrochimica Hydrobiologica. Vol. 21. pp. 38-42., 1993).</ref>

Very few studies have sampled groundwater below infiltration facilities or roadside ditches receiving de-icing salt laden runoff have found concentrations of heavy metals that exceed drinking water standards <ref>Howard, K.W.F. and Beck, P.J. 1993. Hydrogeochemical implications of groundwater contamination by road de-icing chemicals. Journal of Contaminant Hydrology. Vol. 12. pp. 245-268.</ref><ref>Granato, G.E., Church, P.E., Stone, V.J. 1995. Mobilization of Major and Trace Constituents of Highway Runoff in Groundwater Potentially Caused by De-icing Chemical Migration. Transportation Research Record. No. 1483.</ref>

Very few studies have sampled groundwater below infiltration facilities or roadside ditches receiving de-icing salt laden runoff have found concentrations of heavy metals that exceed drinking water standards <ref>Howard, K.W.F. and Beck, P.J. 1993. Hydrogeochemical implications of groundwater contamination by road de-icing chemicals. Journal of Contaminant Hydrology. Vol. 12. pp. 245-268.</ref><ref>Granato, G.E., Church, P.E., Stone, V.J. 1995. Mobilization of Major and Trace Constituents of Highway Runoff in Groundwater Potentially Caused by De-icing Chemical Migration. Transportation Research Record. No. 1483.</ref>

===[[Green Roofs |Green roofs]]===  

===[[Green Roofs |Green roofs]]===  

The survival of [[Green roofs: Planting|green roof plantings]] is greater in winters with long deep sub-zero temperatures. Being shallow and very exposed to warming sunlight, green roofs thaw rapidly. Frequent freeze-thaw cycles in the early and late winter are associated higher loss of vegetation on green roofs.

The survival of [[Green roofs: Planting|green roof plantings]] is greater in winters with long deep sub-zero temperatures. Being shallow and very exposed to warming sunlight, green roofs thaw rapidly. Frequent freeze-thaw cycles in the early and late winter are associated higher loss of vegetation on green roofs.