Geoscience Reference
In-Depth Information
Digital Technology in Geography
make observations. This limitation began to change somewhat
in the early 1900s with the development of airplanes, which
people could use to see places without actually setting foot
on the ground. With the advent of this new technology, ge-
ographers began to use a new approach to spatial analysis
called
remote sensing
, which means measuring properties
of the environment without direct contact. In this manner,
geographers could learn much information about the vegetation
patterns of the landscape, the routes that rivers take across the
countryside, or even the configuration and distribution of ag-
ricultural fields. Remote sensing began to be used in a wide-
spread, systematic fashion in the 1930s when on-board cameras
were developed that could take
aerial photographs
(Figures
2.9c, 2.21) at prescribed intervals of time. With these photo-
graphs, which could be taken in a succession of linear flight
lines, entire counties or even states could be viewed in a sys-
tematic way.
Although aerial photography marked a dramatic leap in
the geographer's ability to study the landscape, this technology
proved limiting because a complete set of photographs of large
regions (like a state) was only taken once every decade, or at best,
at irregular intervals of time. Although this temporal pattern al-
lowed for some studies of landscape change, perhaps by taking
photographs of the same place two or more times over, say, 25
years, geographers were still limited because they could not see
As you are no doubt aware, digital technology is an essential part
of life in the industrialized world today, with personal computers,
cell phones, the Internet, and satellite television common features.
These technological advances have also been very important
in the recent evolution of geography as a scientific discipline,
resulting in expanded work in the field that has increased the need
for skilled people at all professional levels at excellent pay. Much
current geographic research is focusing on the development and
refinement of three digital techniques: Global Positioning Systems
(GPS), remote sensing, and Geographic Information Systems
(GIS). These techniques, used independently as well as together,
enable geographers to use maps and other images in a digital
format in order to increase the speed and efficiency of geographic
research. In addition, the ability to display geographic information
has improved remarkably. The remainder of this chapter focuses
on these new and exciting tools that are revolutionizing how
people are viewing the planet from a geographic perspective.
Remote Sensing
Until the early 20th century, the only way that a geographer
could consistently learn anything about new places firsthand
was to personally conduct fieldwork and collect samples or
Figure 2.21 A typical aerial photograph.
With an aerial photograph you can see a variety of landscape pat-
terns that cannot be viewed from the ground. This aerial photo, for example, shows the pattern of crop fields,
trees, roads, and dwellings at Rajasthan, India.
Remote sensing
The method through which information is
gathered about the Earth from a distance.
Photographs taken of the Earth's sur-
Aerial photographs
face from the air.
