success. To this end, ecological, geomorphological, and socioeconomic criteria are
all taken into consideration.
19.2 Methods
The decision regarding whether a beach should be restored, or even whether it is
possible to carry out restoration actions, is a complex one, involving many diverse
ecological, geomorphological, and socio-economic aspects. For this reason, there is
no common scale by which to by which one can compare sites directly. This variety
of factors also makes it virtually impossible for a single specialist to select the most
representative and effective values. To solve both of these problems, this study
utilized an Analytic Hierarchy Process (AHP) along with the contributions of a
multidisciplinary expert panel. Together, these instruments allowed identification and
weighting of the factors that determine the restoration potential of a beach with dunes.
19.2.1 Factor Selection
An extensive literature review was conducted, collating all the ecological, geomorphological, and socioeconomic information considered relevant to the success
or failure of remedial action. From this review, a list of approximately 100 factors
was compiled. This list was evaluated by three experts in restoration of beaches
and coastal dunes, who eliminated redundant criteria and selected only those
considered most representative. These representative factors were structured
hierarchically and grouped according to criteria, subcriteria, and indicators for
subsequent weighting.
19.2.2 Weighting of Criteria, Subcriteria and Indicators
The criteria, subcriteria, and indicators selected by the experts were integrated into
a square matrix for weighting. Pairwise comparison allowed each criterion to be
weighted, in relation to all the others, in an efficient manner. This comparison was
carried out using a scale from 1 to 4 according to the degree of importance of the
criterion (Table 19.1; modified from Saaty 1980).
Each of the pairwise comparison matrices was summarized, obtaining the total
of each column of the matrix (Fig. 19.2). Each value of the matrix was then
divided by the resulting sum total obtained in each column corresponding to that
value. The result of this division is a normalized pairwise comparison matrix.
The arithmetic average was subsequently calculated with the values from each row
of the normalized matrix, producing a matrix with the priorities of each criterion.
19 Multicriteria Analysis to Implement Actions Leading to Coastal Dune Restoration
309
all taken into consideration.
19.2 Methods
The decision regarding whether a beach should be restored, or even whether it is
possible to carry out restoration actions, is a complex one, involving many diverse
ecological, geomorphological, and socio-economic aspects. For this reason, there is
no common scale by which to by which one can compare sites directly. This variety
of factors also makes it virtually impossible for a single specialist to select the most
representative and effective values. To solve both of these problems, this study
utilized an Analytic Hierarchy Process (AHP) along with the contributions of a
multidisciplinary expert panel. Together, these instruments allowed identification and
weighting of the factors that determine the restoration potential of a beach with dunes.
19.2.1 Factor Selection
An extensive literature review was conducted, collating all the ecological, geomorphological, and socioeconomic information considered relevant to the success
or failure of remedial action. From this review, a list of approximately 100 factors
was compiled. This list was evaluated by three experts in restoration of beaches
and coastal dunes, who eliminated redundant criteria and selected only those
considered most representative. These representative factors were structured
hierarchically and grouped according to criteria, subcriteria, and indicators for
subsequent weighting.
19.2.2 Weighting of Criteria, Subcriteria and Indicators
The criteria, subcriteria, and indicators selected by the experts were integrated into
a square matrix for weighting. Pairwise comparison allowed each criterion to be
weighted, in relation to all the others, in an efficient manner. This comparison was
carried out using a scale from 1 to 4 according to the degree of importance of the
criterion (Table 19.1; modified from Saaty 1980).
Each of the pairwise comparison matrices was summarized, obtaining the total
of each column of the matrix (Fig. 19.2). Each value of the matrix was then
divided by the resulting sum total obtained in each column corresponding to that
value. The result of this division is a normalized pairwise comparison matrix.
The arithmetic average was subsequently calculated with the values from each row
of the normalized matrix, producing a matrix with the priorities of each criterion.
19 Multicriteria Analysis to Implement Actions Leading to Coastal Dune Restoration
309