EARTHSC 2GG3 Lecture Notes - Lecture 19: Aridification, Overgrazing, Smog

• School: Mohawk College
• Department: Earth Sciences
• Course: EARTHSC 2GG3
• Professor: John Maclachlan

Document Summary

Lecture 19, october 18, 2012: hazards related to weather and climate, many hazards are related to weather. Involves lower than average precipitation in region: definition varies depending on effect on people, drop in usable water available in reservoirs, in groundwater storage, or in stream flow. Appears to correlate with warm phase of amo. Image: a giant dust storm sweeps out over the atlantic from the sahara, 2000. Severe drought a(cid:374)d disastrous far(cid:373)i(cid:374)g pra(cid:272)ti(cid:272)es tur(cid:374)ed u. s. plai(cid:374)s states i(cid:374)to (cid:858)dust bowl(cid:859) i(cid:374) (cid:1005)93(cid:1004)s, coinciding with economic collapse of great depression: aridification, or desertification. Si(cid:374)(cid:272)e late (cid:1005)9(cid:1010)(cid:1004)s (cid:373)u(cid:272)h of afri(cid:272)a(cid:859)s sahel regio(cid:374) has lost vegetation cover, due to increased population, intensive cultivation in marginal areas, overgrazing: decades of drought fostered desertification, affe(cid:272)ts a(cid:271)out (cid:1011)(cid:1004)% of dryla(cid:374)ds, 3(cid:1004)% of earth(cid:859)s surfa(cid:272)e. Tropical hardwood forests on marginal soil are cut rapid runoff, soil loss, severe floods, dust storms that travel around world.