Abstract
The main subject of this research thesis concerns in general the
interrelations between rationalisation and quantification in the urban
planning approach, exposed mainly by critical evaluation and development
of one particular quantitative method known as threshold analysis.
Part 1 of the thesis explains the theoretical background of this analysis
developed on the basis of threshold theory. Threshold theory, developed
in Poland by B. Malisz in 1963, states from observation that towns
encounter physical limitations to their expansion which have been called
DEVELOPMENT THRESHOLDS. They are not irremediable but can
be overcome only at 'additional' cost, i.e. at THRESHOLD COSTS which
must either be spent before the land is opened up for development, or
which have to be spread over the period of time. Threshold analysis
in turn allows (i) the identification of thresholds as lines on maps and/or
as points on development curves, and (ii) the calculation of costs
necessary for their overstepping. It therefore creates a framework
for comparison of the 'effectiveness' of development variants and points
out where and how thresholds could be met so that saving of inputs for
expansion can be maximised. The scope of application of threshold analysis
ranges from analysing and comparing urban development possibilities of a
single town to its indirect use in regional planning by providing important
parameters deriving from threshold analysis of all towns within the region
concerned. The recently discovered possibility of direct application of the
threshold concept to regional analyses by analysing 'thresholds' in
exploitation or expansion of regional resources upon which any development
of economic activities depends is also discussed and presented in more
detail.
Part 2 of the thesis concentrates on evaluation of threshold analysis in
urban planning by presenting and assessing results achieved in its
application in Poland and by testing the method in the two Scottish subregional plans, for Grangemouth/Falkirk and the Central Borders.
Similar investigations follow in the field of direct application of threshold
analysis to regional analyses. This approach was tested first by
B. Malisz in Yugoslavia and then within the Planning Research Unit,
Edinburgh University, in the study dealing with angling potential in Ireland.
Part 2 results in a comprehensive and critical assessment of the validity
of threshold analysis with all its advantages and disadvantages clearly
exposed. This finally leads to outlining the implications for further
research necessary if the latent potential of threshold analysis is to be
fully exploited in planning practice.
Part 3 of the thesis, following the criticism of existing forms of threshold
analysis, attempts to take the previously indicated guidelines in order to
improve and refine the whole threshold approach. Firstly, steps are
taken to remove a great deal of confusion about the nature of thresholds,
by developing definitions which in a 'neutral' mathematical way describebasic notions of threshold analysis, and by offering a framework for
classifying thresholds in an unequivocal way. S econdly, the simple form
of threshold analysis is developed into a comprehensive 'model' process
allowing for the introduction into the course of the analysis of all
factors (such as the impact of frozen assets, exploitation costs, etc.) so
far missing, while maintaining its basic simplicity to warrant its
applicability in everyday planning practice. Thirdly, the contribution of
threshold analysis is considered within the context of the overall planning
process, the model of which is proposed both in a simplified and an
expanded version. The role of threshold analysis in its framework is
then discussed with particular emphasis attached to the concept of
integrating it with other complementary techniques (Optimisation Method,
Planning Balance Sheet, and Goals-Achievement Matrix) which may greatly
help in general rationalisation of the urban planning approach.
The conclusions from the research are thus greatly inherent in Part 3, but
the major points deriving are summarised at the end, culminating in the
final statement that threshold analysis is not a complete theory of
planning. It embodies only some parameters for the development of urban
strategy and it does not measure the benefits of alternative urban forms.
It does indicate, however, the cost of these forms and helps to identify
the factors causing variations in these costs. In general it does not
replace other judgments but puts them on a more objective foundation.
