Chapter 16 - Geomorphology, Geography, and Science Bernard 0

GEOMORPHOLOGY, GEOGRAPHY, AND SCIENCE 407
their workings; to further dismantle these components into individual parts; to examine
and describe those parts and their workings, and so on. Unfortunately, it is silent on
methods of reassembly, and the essential chapter revealing to us what we truly seek - the
internal workings of the Earth Machine - remains missing.
Other disciplines, such as chemistry, astronomy, and physics, have begun to take steps
toward reconstructive efforts. Schweber (1993, p. 34), for example, points out that 'the
reductionist approach that has been the hallmark of theoretical physics in the 20th century
is being superseded by the investigation of emergent phenomena, the study of properties
of complexes whose "elementary" constituents and their interactions are known'. The term
'emergent properties' refers, not to the theoretical or mathematical constructs that represent
the fundamental laws which most reductionists seek, but rather, to the characteristic
behavior of solutions to the mathematical expressions that describe natural phenomena.
Recent research on nonlinear dynamical systems in geomorphology (e.g. Phillips 1992 and
references therein) seems particularly germane in this respect. The identification of
emergent properties is not a straightforward task because it involves more than simple
reconstruction (i.e. putting the deconstructed pieces together). This was recognized by
Anderson (1972, p. 393) who suggested that:
the more the elementary-particle physicists tell us about the nature of the fundamental laws,
the less relevance they seem to have to the very real problems of the rest of science, much less
to those of society ... The constructionist hypothesis breaks down when confronted with the
twin difficulties of scale and complexity. The behavior of large and complex aggregates of
elementary particles, it turns out, is not to be understood in terms of a simple extrapolation of
the properties of a few particles.
Anderson (1972) also argued that each scale level should have its own fundamental laws
(i.e. its own ontology) and therefore, its own complexities and emergent properties.
These ideas about distinctly different scale levels have found partial support in
contemporary geomorphological practice (e.g. de Boer 1992; Sherman and Bauer 1993;
Phillips 1995). At the smallest scales, it is not uncommon for scientists to favor concisely
expressed, deterministic relations that invoke force balances or conservation principles (of
mass, momentum, vorticity, entropy, or energy). At intermediate scales, much of the
mathematical formality is retained, but some of the deterministic physics or chemistry are
replaced by parameterizations that invoke phenomenological or constitutive coefficients
such as conductivity, diffusivity viscosity, elasticity, erodibility, porosity, and
permeability, or the various coefficients of drag, friction, cohesion, and strength. These
coefficients are used to relate the principal variables in a given process-response
interaction when accounting for individual particles and their behavior is no longer
possible. Ensemble averaging over domains of interest (representative elemental volumes)
becomes necessary. At the largest scales, descriptions of system behavior usually assume
probabilistic (indeterministic) properties or an idiographic and historical character. One of
the challenges for geomorphologists, then, is to identify the existence and domain of these
scale levels - their bounds, fundamental laws, and emergent properties.
It is worth remembering, however, that some 'laws' may transcend scale in the sense
that they will be characteristic of several contiguous levels. The law of gravity, for
example, applies to most scales of geomorphological interest, as might the principles of
least action, sufficient reason, and uniformity of nature (Yatsu 1992, p. 88). Geomorph-