Geography Reference
In-Depth Information
for visualisation of the movements of humans to visualising those of animals.
Factors influencing the movements of all sentient objects fall in two broad
categories: causes and constraints.
We may use very different terms to describe these characteristics in a human
context, and human technologies as well as the proven human ability to concep-
tualise and rationalise, can transform the entire process of living in an environ-
ment, but the meta-concepts can be held in common by humans and animals to a
large degree. They also permeate the wider expression of time geography by
Hägerstrand in his various papers, where he acknowledges the power of timelines
to reveal human activity but constantly identifies the intermixing of motive,
knowledge, environment, and constraints of various kinds in producing the specific
behaviours and resultant geometric patterns. The timeline itself has been described
as a choreography (Pred
1977
) and as a unique identifier akin to a DNA sample
(Nathan et al.
2008
). In reality it's closer to the transcript of a conversation with
the personal environment in all its aspects. Choreographed dance is perhaps too
regulated and internalized to be a satisfying metaphor. DNA is a reflection of a
construction blueprint in a relatively stable molecular environment: it is a long
bow to draw to compare it with the recording of the activity of a sentient entity in a
constantly modifying and reconceptualised four dimensional space where the laws
are driven by cognitive rather than physical processes. It can be way more
complicated.
2.1 Causes
At this point it may be useful to look in more detail at some of the concepts which
we might consider to underlie sentient movement and the links to the geography of
the environment that is utilised by the entity. What is the vocabulary of why
movement takes place and what influences it?
Activities are fundamental stimuli that work to generate movements in sentient
objects (Yuan and Hornsby
2008
; Zhao et al.
2008
), and it is not surprising that
movements are often grouped by the activities that cause them, e.g., 'travel to
work'. The links among activity and movements are very strong: some activities
are embedded in a phase of movement (e.g., skiing downhill) and some activities
induce the need for movement (e.g. foraging); movement creates spatial and
temporal connections among activities.
Complementarity may help explain movements between areas of demand and
supply. When such movements occur, there is a spatially explicit demand at one
location and a matching supply at another. Although demand and supply induce
this type of movement, it occurs only if there are no intervening complementary
sources of supply (Ullman
1954
).
Intervening opportunities are negative factors that may prevent movements
between areas from occurring, even where there is specific complementarity.
Intervening opportunities offer a closer, cheaper, or more accessible alternative
