Standard 14

The National Geography Standards

	Physical geographers divide the Earth into four spheres for the purpose of study and understanding: the lithosphere (solid rock), atmosphere (air), hydrosphere (water), and biosphere (life). Human activities modify each of these spheres. Sometimes these modifications serve human purposes, sometimes they inadvertently present hazards.
	U.S. Highway 40, Maryland - Modifications of the lithosphere for ground transportation purposes are increasingly common because of modern, earth-moving technologies. Here in Maryland, a road cut makes it easier for drivers to transit mountain ranges. Alternatives to road cuts are switch-back roads and mountain tunnels. This "fresh" road cut makes it easy for students of physical geography to inspect the folded Appalachians' geology first hand.
	Fairview Township, Pennsylvania - Modifications of the biosphere are often achieved by using herbicides and pesticides. Here in Pennsylvania, herbicides have been used to make it easy on highway crews seeking to keep summer vegetation from interfering with traffic. What do herbicides do to community aesthetics?
	An Urban Heat Island around Moscow - Modifications of the atmosphere's temperature are generated by large urban places such as Moscow. In this Landsat image, the February "heat island" around Moscow is marked by the diminished snow cover. Source: NASA, Mission to Earth, 1976, Plate 252.

A Sample Question from the National Geography Challenge 1996 (Grades 10-12) which illustrates . . .

STANDARD 14 -- HUMAN IMPACT ON THE ENVIRONMENT

The primary reason for the massive deforestation practices presently underway in the Amazon Basin in Brazil is to:

1. make space available for the interior development of the country.
2. expand cattle ranches for range grazing.
3. establish feedlots for an expanding corn-livestock industry.
4. encourage the development of the steel, cooper and aluminum industries.