Page 484 - Geosystems An Introduction to Physical Geography 4th Canadian Edition

THEhumanDENOMINATOR 14 Weathering, Karst, and Hillslopes
GEOMORPHIC PROCESSES HUMANS
• Chemical weathering processes break down carvings made by humans in rock, such as tombstones, cathedral ´façades, and bridges.
• Sudden sinkhole formation in populated areas can cause damage and human casualties.
• Mass movements cause human casualties and sometimes catastrophic damage, burying cities, damming rivers, and sending flood waves down-
HUMANS GEOMORPHIC PROCESSES
• Mining causes scarification, often moving contaminated sediments into surface water systems and groundwater.
• Removal of vegetation on hillslopes may lead to slope failure, destabilizing streams and associated ecosystems.
• Lowering of water tables from groundwater pumping causes sinkhole collapse in population centres.
The 71-m-tall Grand Buddha at Leshan in the Sichuan province of southern China is an example of chemical weathering accelerated by air pollution. Carved over 1000 years ago, the statue
is now being corroded by acid rain from nearby industrial development.
[Bennett Dean/Corbis.]
stream.
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Blue holes are typical karst sinkholes located in what are now offshore areas but that formed during times when sea level was lower. The Great Blue Hole near Belize is part of the Belize Barrier Reef Reserve System designated as a World Heritage site by the United Nations. [Schafer & Hill/Getty Images.]
ISSUES FOR THE 21ST CENTURY
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In April 2010, a massive landslide covered parts of a highway near Taipei, Taiwan. The cause of the translational slide is uncertain, as it was apparently not related to earthquake activity or excessive rainfall. [Patrick Lin/Getty Images.]
• Global climate change will affect forest health; declining forests (from disease or drought) will increase slope instability and mass movement events.
• Open-pit mining worldwide will continue to move massive amounts of Earth materials, with associated impacts on ecosystems and water quality. Reclama- tion will help mitigate long-term mining impacts.
• Improved engineering of containment ponds holding industrial by-products will prevent the spread of toxic materials.
geosystemsconnection
We began our study of earth’s exogenic processes with the basic principles of landmass denudation and slope morphology. We then moved on to the processes that deliver materials for erosion and transport: the physical and chemical weathering of rock, dissolution of limestone landscapes, and mass-movement processes. In the next chapter, we examine river systems and the landforms that result from fluvial processes. The erosional and depositional activities of running water, wind, waves and coastal actions, and ice flow through the next four chapters.
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