Environmental Engineering Reference
In-Depth Information
regions is overworked and the soil becomes unusable and depleted of nutrients. Only the increase in
disease is not related to the overworking and overuse of soils.
47.
D
The dead zone in the Gulf of Mexico is a result of excess nutrients entering the water from sources
along the Mississippi River. Agriculture, sewage, urban areas, and industry all add excess nutrients into
the river through runoff, which then carries the nutrients and pollution into the Gulf of Mexico. Excess
nutrients in a water source spur the increase in growth of algae and plankton. More organisms means
more death, and this increased decomposition consumes large amounts of oxygen. When this happens
on a large scale, a hypoxic environment (one that is lacking in oxygen) is created. This lack of oxygen
creates a dead zone.
48.
B
Countries that sign the Kyoto Protocol are mandated to reduce greenhouse gas emissions of six gases
by 2012, when they must be at or lower than 1990 levels. The United States did not sign this treaty be-
cause the requirement was placed on developed, industrialized countries and not on developing nations.
Some developing nations are emitting large amounts of greenhouse gases.
49.
D
The Endangered Species Act protects threatened and endangered species and their habitats, and the
National Environmental Policy Act requires that proper consideration be given to the environment
when federal actions are being taken. The National Environmental Policy Act mandates the use of an
environmental impact statement. In building the dock, endangered species may be affected by its con-
struction and location, so it's important to assess these issues prior to development. If endangered spe-
cies are in the area and if their habitat would be affected by the dock, then the species is protected by
the Endangered Species Act.
50.
A
The Ogallala Aquifer is located under eight states in the Midwestern United States. It is the world's
largest aquifer, but for many decades much of its water has been pumped out and used for farmland
crop irrigation. As a result, the aquifer's volume has been reduced. The recharge of the aquifer is slow
because it is located in an arid region with minimal annual rainfall.
51.
D
Saltwater intrusion can occur when an aquifer is over-pumped and, therefore, decreases in volume. If
this happens near a saltwater source, the saltwater will eventually move in to fill the empty space in the
aquifer.
52.
C
Waterlogging is a result of the overwatering of soils, leading to a rise in the water table and eventu-
ally suffocation of plant roots. Because of the excess water in the soil, plant roots do not get the import-
ant gases necessary for survival.
53.
A
Soil salinization results from salts building up in the top layer of soil. Because of low precipitation in
arid regions, when evaporation occurs, it pulls salts up through the soil. Once the water evaporates, it
leaves the salts on the soil.
54.
B
Biosphere reserves have been created in an effort to incorporate sustainable development with pre-
servation of biodiversity. Managed by the United Nations, they are international efforts. In a biosphere
reserve, the center is used for preservation; the middle area is used for research, tourism, and recreation
(along with limited development); and the outer area is used for sustainable living and agriculture.
55.
D
While dams provide for electricity generation and drinking water, and can control flooding, they also
can have harmful ecological effects. The alteration of the flow of water can impact sedimentation, mat-
ing patterns of fish, and flooding of terrestrial ecosystems. Dams also potentially slow the river's flow
to the point that it has difficultly pushing sediment from its end point in an ocean, lake, or larger river.
56.
B
Habitat islands are sections of one type of habitat or ecosystem that are disconnected from larger
areas of the same ecosystem, essentially creating "islands" of an ecosystem. A habitat island can be sur-
