LAND AS THE RESOURCE - Low Impact Development and Sustainable Stormwater Management - page 64

Figure 3-14 Geothermal energy power plants are limited to plate contacts, such as in New
Zealand.
alternative to fossil fuels (Figure 3-14), but these geothermal energy sources are
limited to geologically active regions along plate contacts.
In deeper aquifers such as the Ogalala formation of the central United States,
the stored water is the result of rainfall from some 2 million years ago, while most
of the water moving near the surface through fractured bedrock or in solution
channels has fallen as rain within the past year or two. For the most part, the
subsurface movement of water is confined to a relatively shallow layer of soil and
weathered bedrock overlaying more dense formations. In the very deep aquifers,
water is highly mineralized and difficult to use for potable supplies.
Physiography
The shape and structure of the land surface determines how and where we occupy
it for habitat. In many historic sites, the locations chosen were intended to take
advantage of difficult site conditions, rather than convenient access or relatively
flat grade. Although the primary determinants of habitat selection for countless
decades were a source of drinking water and protection from the elements, we
also had to consider protection from each other. Many of our seemingly romantic
sites from earlier European history were designed primarily as fortifications along
a river, or hillside structures and villages that were positioned to be very difficult
to access. The geology and landform were selected for the difficulty of the site
rather than the opportunity for land development. Most of these European walled