Ecologists, Farmers, Tourists - GIS
Support Planning of Red Stone Park, China
( This paper is printed from: Geographic Information Research:Bridging
the Atlantic (Craglia, M. and Hellen, C. Eds.)Tayor &Francis.
pp. 480-494.1997
ABSTRACT: Landscape planning is considered as a
procedure of defense taking place among defenders of various processes.
Defending by security patterns (SPs) --strategic portions and positions
-- may significantly increase the efficiency of safeguarding the
processes of our concern. SPs are defined and identified based on
the threshold-type quality of the dynamics of the processes. Alternative
change models are proposed based on SPs. Decision making based on
SPs is also discussed. The SP approach is illustrated by the case
study of the Red Stone National Park, China, in which a defending
procedure among ecologists (defenders of ecological processes),
tourists (defenders of visual perceptual processes) and farmers
(defenders of agricultural conversion processes) is simulated. Integrated
with the SP approach, GIS shows great potential for supporting decision
making in landscape changes.
INTRODUCTION SECURITY PATTERNS AND SP APPROACH
Landscape planning is considered a procedure of defense involving
defenders of various processes. How can we defend the processes
of our concern more effectively while maximising opportunities for
changes? This paper tries to answer this question using the concept
of security patterns (SPs) and demonstrates how GIS can be combined
with the SP approach in landscape planning.
By definition, SPs are the spatial patterns composed of strategic
portions, positions, critical scales (sizes), numbers, shapes and
inter-relationships that are associated with certain thresholds
in the non-linear dynamics of processes in the landscapes. SPs have
or potentially have a critical significance in safeguarding certain
processes, e.g. the process of species dispersal, spread of fire
and other disturbances, visual perception and preference, agricultural
conversion, etc.
In terms of their significance for the processes of our concern,
security landscape components have three basic characteristics:
(i) Initiative, the quality of a portion or position whose occupation
is likely to give it the advantage of initiating certain processes;
(ii) Efficiency, the quality of a position or portion whose occupation
will give it the advantage of less cost in energy and materials
and be much more effective in promoting or controlling certain processes;
(iii) Co-ordination, the quality of a position or portion whose
occupation will give it the advantage of effective spatial communication
among neighboring elements.
SPs are multi-leveled. Each individual process in the landscape
has its own security patterns (Figure 1), and these individual SPs
may compete and overlap spatially.
Furthermore, each individual process has SPs at various security
levels.
Figure 1 A presumed hierarchy of landscape security patterns
The concept of SPs is based on two assumptions concerning spatial
patterns and processes: (a) landscape patterns effect processes,
and (b) there are strategic landscapes associated with some thresholds
in the dynamics of certain processes.
Numerous observations suggest that the spatial patterns of a landscape
influence various ecological processes such as species dispersal
and population dynamics (Forman and Godron, 1986; Turner, 1989);
human processes such as residential development and demographic
dynamics (e.g. Berry and Horton, 1970), and visual perceptual processes
(Gibson, 1950; Lynch, 1960).
Not all portions and positions of the landscape are equally important
in terms of their influence on individual processes, some are more
important than others, and some are strategically critical. Examples
of such strategic portions and positions include the inlets and
outlets of a basin and breaks in a corridor that have critical values
for ecological processes (Forman and Godron, 1986; Merriam, 1984);
the conspicuous land marks, narrow defiles, gorges and bridges that
have significant visual perceptual effects (Stein and Niederland,
1989; Tuan, 1974); as well as certain places that have a strategic
significance for economic processes (Taaffe and Gauthier, 1973).
It is important to note , however, that in some cases various processes
in the landscape may be controlled by spatial patterns that are
not intuitively obvious nor visually apparent to a human observer.
It is assumed that some kinds of thresholds exist in the trajectories
of the dynamics of processes. At some points (in terms of number,
size, shape and inter-distance of landscape elements), a slight
change in landscape property produces sudden changes in the response
of the process. Such thresholds have been recognized in urban development
(Kozlowski, 1986). Similar to thresholds, other concepts have been
proposed that may also be useful in understanding my ideas concerning
the strategic landscape and security patterns such as safe minimum
standards (SMS) (Bishop, Fullerton, et al, 1974; Ciriacy-Wantrup,
1968), carrying capacity, and ultimate environmental thresholds
(UETs) (Kozlowski and Hill, 1993), etc.
It is thus reasonable to assume that:
(1) landscape patterns associated with these critical thresholds
or constraints are likely to be strategically critical in controlling
or promoting certain processes;
(2) landscape design and management following these strategically
critical patterns can more effectively safeguard or control the
processes.
Therefore, it is worthwhile to identify and apply SPs in landscape
planning. The following two aspects of exploration become the major
focus of this paper:
(1) How can we define and identify SPs and what are they?
(2) How can we apply SPs in landscape planning to achieve a less
detrimental landscape, while at the same time, maximally making
changes acceptable to decision makers and/or developers?
These two aspects of inquiry compose an approach to landscape planning
which I call the SP approach, or the approach of security patterns.
It is an approach to defending various processes of our concern,
aiming at a good balance of acceptable changes and a securer landscape
through identifying and applying security patterns (SPs). The SP
approach tries to establish 'stop signs' in the procedures of decision
making for various landscape changes, and to safeguard the security
of the processes at critical points. In a certain sense, defining
SPs is a strategy of spatial defense, an operational weapon of negotiation
aimed at a less harmful change by controlling critical points, or
'frontiers'. Defense by these SPs is expected to be more effective
in safeguarding the landscape processes of our concern. GIS has
great potential when combined with the SP approach in landscape
planning and decision making (see Yu, 1995c for more detailed discussion
on the SP concept).
A case study of the Red Stone National Park in south China, is used
to illustrate the SP approach. This case is selected since it dramatically
represents a defensible procedure of landscape change among defenders
of three interacting, and often competing, processes in landscapes,
including ecological, visual and agricultural conversion processes
.
DEFENDING THE SECURITY OF PROCESSES IN RED STONE
NATIONAL PARK: A CASE STUDY
Red Stone National Park is 313 square kilometers in size (Figure
2). The dominant regional natural vegetation is composed of sub-tropical
Figure 2 The landscape of the Red Stone National Park in South China
evergreen forests which have been seriously destroyed at the peripheral
area with some isolated remnant patches scattered in the remote
areas. The landscape is made up of hundreds of heavily eroded rocky
hills, square with flat top and steep slopes. This unique land form
is the primary factor affecting the distribution of soil, vegetation,
wildlife habitats, visual quality and agriculture. The remnant biological
islands are extremely valuable in terms of biodiversity conservation
and landscape restoration. The visual quality is extraordinary .
It is one of the major tourist attractions in south China. The fertile
soil and sub-tropical climate make this land one of the most productive
agricultural areas. About twenty thousand farmers live in seventy
villages scattered in the small alluvial planes in this hilly landscape.
The problems this national park now faces are typical of other national
protected areas, namely, the conflicts between development , ecological
and visual conservation. Landscape planning in this park is a defensible
procedure dramatically taking place among defenders of various processes.
As a result, this case study a an illustrative example for the SP
approach.
Three processes are concerned in this case study: ecological, visual
perceptual, and agricultural. The objectives in this case study
are to explore an effective way of defending various landscape processes
in this national park by identifying and applying SPs, and to demonstrate
how GIS can be integrated into the defensible procedure of landscape
change and decision making.
Security patterns in the Red Stone National Park
Ecological SPs: Ecologists' Defensive Frontiers
Ecological processes concerned in this case are species dispersal
and maintenance. Three groups of species are targeted: medium-sized
mammals (Cervidae and Viverridae families), pheasants (Phasianidae
family) and amphibians (Cryptobranchidae and Ranidae families).
These species are native to this region and have an endangered status.
Ecological SPs are identified by analyzing accessibility surface
that represent the potential coverage by the species of our concern.
Accessibility surfaces are developed using a minimum cumulative
resistance(MCR) model (Knaapen, Scheffer and Harms, 1992; Yu, 1995b),
this model conceives the dynamics of species dispersal as a function
of sources, distance and intermediate landscapes. Native habitats
of the target species are taken as sources of dispersal. Intermediate
landscapes are evaluated for their resistance to the dispersal of
species, and the dynamics of the dispersal process is simulated
based on the cumulative resistance to the dispersal of a certain
species. Comparative resistance values are assigned to various landscape
attributes. Various factors such as cover, slope, elevation and
aspect may contribute to the resistance value of each cell of the
landscape. The probability of successful access to a cell by a species
can be expressed as:
i = n
Accessibility = f Min _(Di * Ri)
i = 1
where f is some unknown but monotonically decreasing function. Di
and Ri respectively represent the distances (number of cells) and
resistance when a species travels across landscape type i. While
f is some unknown function, the sum of the weighted distance (Di*
Ri) , or the 'cumulative resistance' can be taken as an indication
of relative accessibility of the cell to the species through one
possible route. There are numerous routes from the sources to the
cell, and the routes with the lowest cumulative resistance, namely
minimal cumulative resistance (MCR) can be used as the relative
measurement of the accessibility of this cell from the sources (habitats
of target species).
Resistance classification (Ri ) is based on individual cells of
25 by 25 meters in size. An interactive interface of the GIS model
using ARC/INFO is developed to allow the processing of more precise
data. Land use and land cover are the major factors contributing
to the resistance of the landscape. In our case, it is reasonable
to assume the more similar a cell to the natural habitats the less
the resistance to the target species of our concern. Eight major
land use and land cover categories are observed and they are closely
associated with the degree of naturalness or the intensity of human
disturbances; these categories range from developed areas to agricultural
fields, grass lands, shrubs, coniferous forests, mixed forests,
the remnant subtropical forests and water. From developed area to
the remnant sub-tropical forests, the degree of human disturbance
increases, in this case it is assumed that the resistance to the
dispersal of native target species increases accordingly. The developed
areas (including roads, housing, tourist service center) have the
highest resistance to all target species (assigned a value 10) and
the natural remnant forests the lowest resistance to the target
species (assigned value 0) . Water bodies are assigned a high resistance
value to the medium-sized mammals but have a moderate resistance
to pheasants and low resistance to amphibians (here the quality
of water is considered).
The topographical factors including elevation and slope also contribute
to the resistance to some species. For the medium-sized mammals
in this case, gentle slope is considered to have less resistance
than a steep slope, the extremely steep slope becoming a barrier
to movement. For the pheasants, these topographical factors are
not important. Amphibians are sensitive to the hydrological situation,
which, in this case is associated with the elevation because of
the unique geological formation of this area.
Based on the resistance map, an accessibility surface can be developed
using the function discussed above. The resultant accessibility
surface resembles a topographic surface that is made up of equal-valued
MCR contours. Following Warntz's model of surface interpretation
(Warntz, 1966), it 'dips' at the sources, has 'peaks' that are least
accessible to target species, has 'courses' with lower MCR value
and run from 'pits ' to 'pits', and has 'ridges' with higher MCR
values and run from 'peak' to 'peak'. On each of the 'courses' or
'ridges' there is one 'pale' or 'pass'. From the MCR surface, one
can also recognize the potential cliffs where values increase or
decrease dramatically, and the potential flat planes where the species
can spread quickly over the landscape.
The accessibility surface, therefore, reveals the potential patterns
of coverage by the target species and the strategic values of landscape
in terms of species dispersal and maintenance (Yu, 1995a-b). Based
on the features of the accessibility surfaces, four structural components
can be identified: buffer zones, inter-source linkages, radiating
routes and strategic points. These four components, specified by
certain quantitative and qualitative parameters, together with the
identified sources (native habitats) compose a security pattern
(Figure 3). Changes in these components, quantitatively or qualitatively,
will dramatically affect the security of the targeted processes.
Figure 3 A schematic picture showing a typical ecological SP
Among others, three series of ecological SPs are identified respectively
at high, moderate and low security levels for different groups of
species, e.g. Figure 4-6 for the medium-sized mammals in this case.
They could be combined into corresponding overall ecological SPs.
These ecological SPs can be used by ecologists as defensive frontiers
for the defense of the ecological processes at various security
levels in the process of landscape planning and change.
Figure 4 An accessibility surface for the medium-sized mammals and
an ecological SP at a less secure level. The SP is composed of sources,
strategic points and shortest inter-source linkages
Figure 5 An ecological SP for the medium-sized
mammals at a highly secure level. The SP is composed of sources,
strategic points, all possible inter-source linkages, big buffer
zones and some radiating routes
Figure 6 An ecological SP for the medium-sized
mammals at a moderately secure level and the impact of tourist development.
The SP is composed of sources, strategic points, some inter-source
linkages and some buffer zones.
Visual SPs: Tourists' Defensive Frontiers
The visual SPs are defined on the basis of critical landscape interpreted
by visual sensitivity surfaces which are a combination of landscape
visibility and preference evaluation. The calculation and mapping
of landscape visibility were carried out using function that most
GIS packages contain. GIS mapping of landscape preference is relatively
more complicated. Firstly, 572 individual from China and USA were
interviewed as to their preference evaluation for various landscapes
in the case study area (for detailed discussion see Yu, 1995c).
Secondly, factor analysis and regression analysis were used to build
the preference models. These preference models show the contributions
of various spatial information to the visual quality of the landscape.
This spatial information consists of landscape elements including
water, rocks, vegetation, tourist service buildings, fields, weather
conditions, and spatial dimensions associated with the position
of viewers including foreground, mid ground and background. Both
types of spatial information are classified, mapped and analyzed
using GIS. Finally, GIS was used to develop the landscape preference
map based on the landscape preference model and the spatial information.
The visual security patterns (SPs) are defined in association with
various security levels. Using the histograms of visibility and
preference distribution patterns, some thresholds can be identified
and used for the identification of visual security levels (Yu, 1995b).
Three levels of SPs are identified: low, medium and high. These
visual SPs could be used as defensive frontiers by the defenders
of visual perceptual processes and tourism during the procedure
of spatial bartering and bargaining.
Agricultural SPs: Farmers' Defensive Frontiers
Local farmers have depended on their land for hundreds of years.
Population growth requires more land to be converted into agricultural
fields. In a certain sense, agricultural conversion in this case
study is an issue of survival of the local people in this area.
The potential security levels farmers want to achieve are normally
determined by socio-economic analysis on local, regional and even
national scales. This case study addresses the issue of agricultural
SPs based on investigation of the landscape at the local scale and
focuses on the issue as to where land conversion should pause or
accelerate in terms of efficiency of productivity and impact on
other processes in the landscapes.
The procedure of identifying agricultural SPs and ecological SPs
is similar. Agricultural conversion is considered a process of disturbance
with the seventy villages in the study area taken as the source
of the spread of the disturbance. The intermediate landscapes are
evaluated according to their resistance or cost of agricultural
conversion. A convertibility surface (or the potential of conversion)
is developed based on the cumulative resistance of intermediate
landscapes. Based on this convertibility surface, agricultural SPs
are identified at some thresholds or strategic values. Various agricultural
SPs were identified corresponding to different security levels:
low, medium and high. They could be used as defensive frontiers
by defenders of the process of agricultural conversion in the spatial
bargaining and bartering of landscape change and decision making.
Alternative Changes Based On SPs
Various alternative change models can be developed based on SPs.
To illustrate this case four change alternatives are discussed as
examples:
Differentiation Of Management Concentrations Based On SPs
At the highest level of the management hierarchy is the differentiation
between landscape conservation, development (mainly agricultural
conversion) and an integration of both (Figure 7). The general management
differentiation can be further sub-categorized, when the environmental
concern is specified into ecological and visual aspects. A weighing
system has to be used when combining SPs of various ecological processes
into an overall ecological SP. In this case, it is assumed all of
the individual component SPs have the same weight (= 1).
Figure 7 Management differentiation based on two general SPs of
environmental conservation and agricultural conversion
Strengthening Landscape Infrastructures Based On SPs
Taking ecological processes as examples, landscape ecological infrastructures
can be strengthened by consolidating the SP components . These consolidations
include, but are not limited to, the following aspects of improvement
in quantity and quality:
(1) Increasing the buffer zones and making the intermediate landscapes
more hospitable to native species, (2) having alternative linkages,
widening the linkages and improving the connectivity of the linkages,
(3) widening the radiating routes with native plants, (4) introducing
native patches at the strategic points and expanding their dimensions.
By these quantitative and qualitative improvements of the components
of the ecological SPs, the security of the landscape for the ecological
processes can be improved proportionately. This gradual procedure,
however, after reaching a certain threshold, will dramatically increase
the security of the landscape and another security level for ecological
processes will be achieved, e.g. from Figure 4 to Figure 5.
Modifying Introduced Change Models Or Trade-Off Sps And Exercising
Spatial Bartering Based On SPs
Figure 6 shows a proposed tourist development plan and its potential
impact on the ecological SP for the dispersal of medium-sized mammals.
As a result, the remaining native habitat at the upper-right corner
and the immediate buffer zone will be destroyed by the expanding
construction of tourist facilities and three ecological corridors
will be negatively affected by the tour line.
One solution to reduce the negative impact of tourist development
is to modify the plan of tourist development based on ecological
SPs. This solution suggests moving the tourist center to the edge
of the park and imposing a special management policy on the tour
sections across the ecological corridors.
It is, however, possible that any modifications of the tourist development
plan may not be acceptable to the developers or local officials.
In this case, the defender of ecological processes should consider
the solution of spatial bartering to trade-off components of SPs
for their overall consolidation. This solution of spatial bartering
may include, but is not limited to, the following tactics (Figure
8).
Figure 8 Possible spatial bartering tactics based on ecological
SPs
Figure 9 shows an example of how the tourist development plan can
be adapted by trading-off some components of ecological SPs, but
not security levels. It is suggested that the ecologist may abandon
the native habitat at the upper-right corner of the map, but restore
a native patch at the middle left and add a corridor to connect
the two existing patches that will potentially be isolated because
of the interruption of the corridors by the introduced tour line.
Figure 9 Tourist-development plan and spatial bartering on an ecological
SP for the medium-sized mammals as a moderately secure level
It should be noted that all the gains in Figure 8 are based on the
identified ecological SPs and the accessibility surfaces that represent
the accessibility of the landscape.
SP Approach Integrated with GIS in Support of Decision Making for
Securer Landscape Changes
Those identified SPs at various security levels are the basis of
strategies of spatial defense, or spatial bartering among defenders
of ecological, visual and agricultural conversion processes, represented
by ecologists, tourists and farmers .
Two situations have been simulated when using SPs in support of
decision making:
situation one: negotiations for landscape changes within currently
defined security levels. This is an optimistic result of the SP
approach. Any of the four change models proposed in the last section
may be acceptable.
situation two: negotiations for landscape changes beyond current
security levels.
Situation one can be taken as a special case of situation two where
further solutions will be explored at other security levels. In
situation two, one or more defenders has to give up his current
requirement for the security of the concerned processes, and retreat
to a lower level of security for further defense. Figure 10 shows
the negotiation or gaming procedure and the strategies that reflect
the decision making process among the defenders of the three processes,
each of the defenders has SPs of three security levels in mind.
This procedure of redefining security levels may repeat until solutions
can be found.
Figure 10 Strategies for negotiation and GIS-support
decision making based on SPs
As is shown in this case study, planners do not provide the optimum
solutions or even any solutions at all to solve some projected problems.
Instead, they are neutral consultants and moderators providing alternative
strategies for each of the defenders in their defending various
process in the landscape. These strategies are comparatively more
efficient in achieving corresponding utility goals. The final solutions
are the acceptable results achieved through the negotiation among
all defenders of the processes. GIS has great potential both in
the defining of those spatial strategies based on the identification
of SPs, and in the defensive procedure of negotiation among defenders
of various processes.
CONCLUSION
The general conclusion of this research is that landscape security
patterns (SPs) could be very useful in landscape planning aimed
at safeguarding various processes. Security patterns can be used
as impact models guiding the modification or improvement of proposed
change plans, as constraint criteria controlling the maximization
course of individual processes, as blue prints for the improvement
of landscape structure, and as a basic reference frame for the procedure
of spatial bartering.
The SP approach makes policy and management practice specify and
concentrate on certain areas which can increase the efficiency of
the decision making procedure. Various landscape change alternatives
are explored based on SPs within a certain security level for a
certain process. Further change alternatives are developed at a
lower security level only when none of the alternatives at a higher
security level is acceptable to decision makers or defenders of
various processes. SPs are 'stop signs' in the decision-making course
that reduce the risk of the irreversibility of decision making and
reduce the possibilities of catastrophes in landscape changes.
GIS play an important role in simulating various processes, identifying
security patterns, evaluating impact and developing landscape change
models based on SPs. GIS shows its great potentials when combined
with the SP approach in supporting landscape decision making.
ACKNOWLEDGE: Thanks are due to Carl Steinitz, Stephen
Ervin and Richard T. T. Forman at Harvard University for their advice
and support of this research, Hugh Keegan and other staffs at the
ESRI (Environment Systems Research Institute) for their support
in the application of ARC/INFO GIS, and Erin Crowley for her editing
of the manuscript.
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