Geography Reference
In-Depth Information
Chapter 2
The physical dimension: our
natural environments
Study of the natural environment has always been an essential
part of geography and forms the focus of this chapter. Physical
geography may be defi ned as the natural environmental science
of the Earth's surface. But what are its characteristics, and how
did they develop? How does physical geography interact with the
other sciences that investigate the Earth's natural environments,
and what exactly is its special role?
Geo-ecosphere: the playing fi eld
Thinking of the Earth's surface as the 'geo-ecosphere' - the narrow
surface zone comprising all the landscapes of the Earth - is
helpful in defi ning the overall scope of physical geography as
depicted in Figure 4(A). The geo-ecosphere can be subdivided
into six component spheres, each of which has attracted its
own specialist physical geographers. Thus, the topography of
the Earth's land surface (toposphere) can be seen as the focus
for geomorphology; the totality of life on Earth (biosphere) is
the focus for biogeography; and the lower layers of the gaseous
envelope (atmosphere) are the focus for climatology. Other
important spheres identifi ed in Figure 4(A) are the pedosphere,
which involves the soil cover of the Earth; the hydrosphere,
which incorporates the liquid water in rivers, lakes, oceans, and
