Geoscience Reference
In-Depth Information
collecting data from gaging stations about the amount of water
in the streams during the drought and comparing those values
to normal water levels. In all probability, the amount of water
dropped significantly during the drought, which, in fact, is re-
flected in Figure 1.4. The reason for this decreased water level
is that a significant drought would result in less water flowing
from the atmosphere (as precipitation) to Earth. As a result, less
water would then be available as an input to streams across the
Earth's surface. In addition, the quantity of water stored in the
ground likely decreased, which would also have reduced river
levels because a great deal of water in streams is derived from
the ground. Potential further impacts of this drought could have
been that some forms of vegetation became less common or that
the likelihood of fire increased.
This topic systematically explores these kinds of cause-and-
effect relationships in a variety of ways. One way is through the
traditional use of text accompanied by photographs, diagrams,
and tables. Each chapter contains detailed discussions that con-
nect important concepts to events that you may have experienced.
shore was extensively flooded. Before the storm reached land, ge-
ographers were at the forefront of the effort to monitor the storm's
path and predict where the most significant damage would occur.
Once the storm passed, geographers began conducting research
on the impact that the hurricane had on a variety of issues, includ-
ing the shape of the coastline, the distribution of wetlands, and the
regional economy. These studies have profound implications for
future environmental decisions, politics, and economic develop-
ment in the region. Most chapters of this topic contain sections
specifically devoted to such human-environment interactions,
including a discussion of solar energy production in Chapter 4,
wind energy in Chapter 5, and petroleum in Chapter 12. The final
chapter (Chapter 20) is devoted entirely to these kinds of issues
and demonstrates how physical geography is highly relevant to
human-environmental interactions.
Geo Media Library: An Interactive Tool
These holistic discussions in the text are accompanied by graphics
and photographs, as well as a more dynamic tool—the Geo Media
Library. This consists of a variety of animations and simulations
that allow you to visualize and manipulate many of the factors
associated with geographical processes and to see the results over
time and space. The animations and simulations will enhance
your learning as you participate more closely with geographical
processes and will reinforce the interactive nature of the discipline
by showing related variables in motion. The media are integrated
entirely within the chapter text as distinct sections that explain
what you should expect to learn by interacting with them.
Here is a good example of how the Geo Media Library will
enhance your learning. Let's again use flowing water in rivers
as an example because it is easy to visualize. This concept is
described in great detail in Chapter 16 where it is accompanied
by a variety of diagrams that illustrate how water flows, using
flow lines and arrows embedded within them. It is also supple-
mented by several animations that are accessed through the Geo
Media Library
or on the text's accompanying website. One of
the animations in that chapter shows how streams snake across
the river valley in a process called
meandering
. Through this
process, the geographical position of streams actually moves
through time. The Geo Media Library shows this process in
animated form, which will enable you to comprehend it better.
Have a look now to see what these animations are like.
Emphasis on Human Interactions
with the Environment
Many of the scientific analyses associated with physical geog-
raphy are driven by the growing impact that human activities
have within and among the Earth spheres. Given the nature of
human impact on the natural environment, physical geography
is at the forefront of research on many environmental issues that
face the world today. Among just a very few of these issues are
the following.
•
Global climate change
—Human industrial activities are
increasing the levels of carbon dioxide in the atmosphere.
Abundant scientific evidence suggests that this relation-
ship is contributing significantly to global climate change.
•
Deforestation
—The clearing of the tropical rainforests is
occurring at a very rapid rate, leading to soil erosion, loss
of wildlife habitat, and species extinctions.
•
Farmland loss
—Due to increasing global population,
farmland is being converted to zones of economic devel-
opment and residential housing. This loss of farmland is
resulting in more intensive farming of agricultural soils still
in use, which increases the risk of soil erosion and pollution
due to the extensive application of fertilizers and pesticides.
•
Natural hazards
—Hazards occur when extreme events
result in danger to humans. Examples of natural hazards
include hurricanes, tornadoes, flooding, earthquakes, and
volcanoes. Natural hazards are a particularly important
area of geographical study because as the global popula-
tion grows, increasing numbers of people are moving into
areas that are susceptible to extreme natural events.
A recent natural disaster in the United States vividly illus-
trates the integrated nature of physical geography and the criti-
cal role that geographers play with respect to solving real-world
problems. As you probably know, Hurricane Sandy devastated the
East Coast in the fall of 2012, causing many deaths and billions
of dollars of damage, much of it occurring when the New Jersey
Focus on Geographical Literacy
In addition to improving your overall understanding of physical
geography and how it relates to human/environmental issues,
another goal of this topic is to enhance your geographical lit-
eracy. It is common knowledge that the overall geographical
literacy of most Americans is very poor. How many Americans
can identify, for example, the countries of the Middle East,
where so much of our national focus is presently centered? Do
they know the location and character of Afghanistan, which is
where we continue to engage in the longest war in our history?
In a similar vein, how many people understand the science as-
sociated with the issue of ongoing climate change, or why hur-
ricanes may raise the cost of gasoline at the pump?
