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.