EESA06H3 Lecture Notes - Lecture 10: Surface Runoff, Holocene Climatic Optimum, Permafrost
EESA10H3: lecture 10
• Exposure: Opening where you can see what is underneath
• Environmental Science: Cannot do without some knowledge of geology
• Anthropocene: Last 200 year Industrial resolution an forward —>Areas changed as result of human activity
The Epoh of Ma
• Biotervation: rock older than 600 million years old are pristine and can be easily interpreted
o But as you move through the years, you get burrowing of organisms and destroy the original
structure
o Related to Anthropocene as Humans are destroying that original format of the land
• Impacts of Human Activity
o Urban Sprawl: Large super-cities harden the landscape (Roads/Building) see more runoff. Impacts
of weather are stronger because we are changing that landscape
o Toronto covered in fill: Waster products that have been dumped and built on top of. They have
contaminants. NYC is built on fill
o Llod’s Cit Risk Ide aalses the potential impact on the economic output of 301 of the
orld’s ajor ities fro aade ad atural threats.
▪ Shows how government, bus, communities are highly exposed to systemic catastrophic
shocks and could do more to mitigate risk and improve resilience.
▪ Identifying risk, modelling and measuring their impacts and investing in greater
resilience are the first steps.
o Base Flow: Water/Rain etc. going down through geology, Groundwater
▪ Keeps river flowing in the summer
o Overland Flow: Runoff
o Most rivers in urban areas struggle: Surface runoff = Erosion
▪ Surface runoff flushes contaminants off roads
▪ “o elts: First Flush —>Contains Contaminants
▪ Hydrograph: Shows # of water flowing through rivers
o Don River: Has many contaminants: “ik
▪ Has a right-angle bend as it enters the harbor
▪ Fills up with sediments and can encounter flooding
o Saguenay Floods: The size of the damns was inadequate to deal with the runoff
o NW Territories experience warming: The coldest areas of Canada are dealing with warming.
▪ Economic Problem: Permafrost —>Ground/Rock/Sediment freeze.
❖ It will thaw 1-3 m (Active Layer). Under that is permanently frozen
rocks/sediment. (about 700m)
❖ Areas where ground temperatures remain below freezing year-round resulting
in frozen sediments/rock. Only a thin layer immediately below ground surface
thaws (Active Layers)
❖ Continuous Permafrost
❖ Discontinuous Permafrost
❖ Most severe environmental effects of climate warming are being most keenly
felt in the sub-arctic and arctic in areas of permafrost.
❖ Ice Sediment: Sediment that is frozen/trapped in ice.
❖ Permafrost Table: Boundary between Active Layer and Icey Sediment
❖ As something heats = Expands. As the ground surface thaws it is pushing
everything below it down (Subsidence)
o Thaw Ponds: Formed During Hypsithermal Warm Period, c. 5000 Years Ago
• Warmest of the last 10 000 years
o Muskeg: Swamps/Wetlands that cover large areas of the north
• Orgai Terrai
• Can only cross through them in winter when they freeze over
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Impacts of weather are stronger because we are changing that landscape: toronto covered in fill: waster products that have been dumped and built on top of. Llo(cid:455)d"s cit(cid:455) risk i(cid:374)de(cid:454) a(cid:374)al(cid:455)ses the potential impact on the economic output of 301 of the (cid:449)orld"s (cid:373)ajor (cid:272)ities fro(cid:373) (cid:373)a(cid:374)(cid:373)ade a(cid:374)d (cid:374)atural threats. Shows how government, bus, communities are highly exposed to systemic catastrophic shocks and could do more to mitigate risk and improve resilience. Identifying risk, modelling and measuring their impacts and investing in greater resilience are the first steps: base flow: water/rain etc. going down through geology, groundwater. Keeps river flowing in the summer: overland flow: runoff, most rivers in urban areas struggle: surface runoff = erosion. (cid:374)o(cid:449) (cid:373)elts: (cid:862)first flush(cid:863) >contains contaminants: hydrograph: shows # of water flowing through rivers, don river: has many contaminants: (cid:863) i(cid:374)k(cid:863, has a right-angle bend as it enters the harbor. Fills up with sediments and can encounter flooding.
