Once the relative importance of each criteria and subcriteria was estimated, and
in order to determine the stability of the system and assess the quality of the
judgments made by each expert, the consistency ratio (CR) was calculated.
The CR is the ratio of error committed by the expert to the random error. Twelve
experts were each asked to contest an evaluation matrix, but ultimately it was only
possible to take eight into account. The matrices that were chosen were those with
less than 10 % inconsistency, i.e., those with 10 % or fewer incorrect answers.
Matrices with greater ‘‘inconsistency’’ values (5 cases) were returned to the
experts for review. In 4 cases, the matrices were not corrected on time and
therefore had to be eliminated, resulting in the total of 8 considered here. The 8
‘‘consistent’’ matrices were averaged and the relative importance calculated of
each of the criteria, subcriteria, and indicators as described above.
19.3 Results
19.3.1 Selection Criteria
Based on the literature, four criteria, 10 subcriteria, and 38 indicators were
extracted. The four criteria evaluated are listed in Table 19.2 and the subcriteria
and indicators for each criterion can be seen in Fig. 19.3.
19.3.2 Weighting of Criteria and Field of Expertise
Although at first the panel was composed of equal numbers of experts for each of
the areas covered, not all of them completed the process. This produced a slight
imbalance, resulting in a greater number of experts in some areas than others.
For example, there were 5 ecologists (2 functional ecologists, 3 experts in the
restoration of beaches and coastal dunes), 2 geomorphologists, and only 1
anthropologist. This was partially offset by the fact that some of the ecologists had
experience with geomorphological aspects and with work in human communities.
Each of the members of the panel had expertise in a particular area and their
opinion was unique; even those belonging to the same disciplines had had different
experiences so that their views also differed; nevertheless, it was possible to group
their decisions under the different criteria with different relative importance.
Table 19.3 shows the five most important factors identified by each group of
experts and their weighting, normalized for easy comparison. It can be seen how 3
of the 4 groups of experts identified the extraction of sand as being the determining
factor for achieving the restoration of a dune. However, there were wide differences among the other choices: Ecologists considered the biotic elements of
the system as determinants, but this opinion was not shared by other groups.
19 Multicriteria Analysis to Implement Actions Leading to Coastal Dune Restoration
311
in order to determine the stability of the system and assess the quality of the
judgments made by each expert, the consistency ratio (CR) was calculated.
The CR is the ratio of error committed by the expert to the random error. Twelve
experts were each asked to contest an evaluation matrix, but ultimately it was only
possible to take eight into account. The matrices that were chosen were those with
less than 10 % inconsistency, i.e., those with 10 % or fewer incorrect answers.
Matrices with greater ‘‘inconsistency’’ values (5 cases) were returned to the
experts for review. In 4 cases, the matrices were not corrected on time and
therefore had to be eliminated, resulting in the total of 8 considered here. The 8
‘‘consistent’’ matrices were averaged and the relative importance calculated of
each of the criteria, subcriteria, and indicators as described above.
19.3 Results
19.3.1 Selection Criteria
Based on the literature, four criteria, 10 subcriteria, and 38 indicators were
extracted. The four criteria evaluated are listed in Table 19.2 and the subcriteria
and indicators for each criterion can be seen in Fig. 19.3.
19.3.2 Weighting of Criteria and Field of Expertise
Although at first the panel was composed of equal numbers of experts for each of
the areas covered, not all of them completed the process. This produced a slight
imbalance, resulting in a greater number of experts in some areas than others.
For example, there were 5 ecologists (2 functional ecologists, 3 experts in the
restoration of beaches and coastal dunes), 2 geomorphologists, and only 1
anthropologist. This was partially offset by the fact that some of the ecologists had
experience with geomorphological aspects and with work in human communities.
Each of the members of the panel had expertise in a particular area and their
opinion was unique; even those belonging to the same disciplines had had different
experiences so that their views also differed; nevertheless, it was possible to group
their decisions under the different criteria with different relative importance.
Table 19.3 shows the five most important factors identified by each group of
experts and their weighting, normalized for easy comparison. It can be seen how 3
of the 4 groups of experts identified the extraction of sand as being the determining
factor for achieving the restoration of a dune. However, there were wide differences among the other choices: Ecologists considered the biotic elements of
the system as determinants, but this opinion was not shared by other groups.
19 Multicriteria Analysis to Implement Actions Leading to Coastal Dune Restoration
311