cialdea & sollazzo - input2012
DESCRIPTION
Donatella Cialdea and Antonio Sollazzo on "Visibility analysis for identifying detractors in rural areas"TRANSCRIPT
Seventh International Conference on
INFORMATICS AND URBAN AND REGIONAL PLANNINGPlanning Support Tools: Policy Analysis, Implementation and Evaluation
Department of Land Engineering
University of Cagliari (Italy)
Visibility analysis for identifying Visibility analysis for identifying
detractors in rural areasdetractors in rural areas
Cialdea Donatella, Sollazzo Antonio
University of Molise, L.a.co.s.t.a. Laboratory,
Faculty of Engineering, Italy
University of Cagliari (Italy)
10-12 May 2012
IntroductionIntroduction
This work aims to highlight the importance
of the analyses of the visibility undertaken
on a portion of landscape characterised by
its strongly rural features.
Perceptive control alone cannot be
associated with a total control of the
Individuation of the sample area (Low Molise)
(source: our elaboration on Molise Region’s datas)
associated with a total control of the
landscape but can become an important
tool for monitoring transformations in
particular areas of the territory and a
useful tool in the territorial planning
process.
Case Study AreaCase Study Area
The case study area chosen to test the
analysis methodology is the one of Low
Molise, including coastal and pre-coastal
municipalities.
The choice of the area isn’t casual, in fact
this is one of the most important
landscape area of all the Region.landscape area of all the Region.
Contemporary, this is an area that suffered
a great number of transformations.
Landscape featuresLandscape features
The section of the territory involved in this
research is a good example of how a very
rural territory has been transformed and
continues to change over the years.
The study area is made up of a series of
elements which together form the image elements which together form the image
of the landscape. These elements have
been synthesised into two large groups,
Values and Detractors.
ValuesValues
Values are elements conferring value to
the entire landscape system, that may be
different (such as architectural,
naturalistic, historical elements).
They have been divided into two groups:
residual and naturalistic values.
The first group comprises what remains of
areas of great natural worth and are the
historical memory of these places.
The second group comprises those areas
with the recognised presence of an
element of great naturalistic worth, that is
the presence of particular species of flora
and fauna.
DetractorsDetractors
The detractors in some way penalize this
system.
The detractors list is not exhaustive, it has
been prepared after a detailed territory
reading with its typical agricultural
features.
Individuation of Detractors in the sample area (Molise)
(source: our elaboration on Molise Region’s datas)
These elements, therefore, are those that
most modify the rural areas of the region.
Perceptive AnalysisPerceptive Analysis
The perceptive analysis is defined as a
summarize between the analysis of visibility
and of distance.
The first is directly correlated to the height of
each single element and its geographical
position (including height above sea level).
The second is correlated to the distance
within which it is possible to perceive its
presence.
This type of analysis was undertaken in
ArcGis, using respectively the commands
Euclidean Distance for the calculation of
distance and Viewshed for the calculation of
visibility.
Analysis of VisibilityAnalysis of Visibility
In this specific case we used the command
Viewshed which, from the point of view of
data processing, corresponds to a grid in
which each cell has a value of visibility,
representing the number of observation points
from which the chosen horizon can be seen.
Visibility analysis is applied on a DEM and is
Analysis of Visibility in the sample area
(source:our elaboration on Molise Region ‘s datas)
Visibility analysis is applied on a DEM and is
calculated bearing in mind the altitude of the
observation point and of the area falling within
the field of vision.
Combination between Combination between
Visibility and DistanceVisibility and Distance
Appears, in fact evident that are present
within the territory elements which interfere
with the visibility. These elements are not only
of orographic origin. In fact, we have also
wooded, industrial and urban areas. Therefore
we correct the original datum of DEM using
the Land Use datum, attributing them with the
Combination between Visibility Analiysis an Distance Analysis in the
sample area (source: our elaboration on Molise Region’s datas)
the Land Use datum, attributing them with the
average height.
From these data have been realized the two
grid (distance and visibility) and then they
were combined to form a final grid which has
a base cell like that of the DEM and values
varying between 0 and 5 (0 corresponding to
invisibility while 5 corresponds to maximum
perception.
ConclusionsConclusions
The research is developing an innovative territorial analysis
methodology.
The analysis of visibility is a major innovation in the research
field of spatial analysis. It focus on the perceptive analysis
that it is a fundamental feature of the landscape analysis.
Visual perception so was included in an larger territorial
analysis in order to highlight the areas in which already exists
Wind Farm near a rural house in Rotello (Molise) (photo by: A.Sollazzo)
analysis in order to highlight the areas in which already exists
a detractors strong impact of the ones who, however, are still
slightly contaminated by the presence of these elements.
This analytical approach is very useful, for example, in the
planning stage and in the policies determination for
implantations of the renewable sources energy production.
The perceptive analysis, then, has universality and
repeatability characters that make it applicable at all kinds of
territory, unless changes related to the nature of places.