Using GIS for Siting Artificial Reefs
127
QUALITY
The quality of available data varies considerably. In part, if it is archival data, this is not
surprising as methods of data collection and the equipment used have improved
considerably over time. Some data may have been surveyed by trained professionals
whilst others had been collected by amateur volunteers. Some datasets may themselves
have been previously compiled from multiple and unspecified sources in different
formats and thus are devoid of standards and are potentially more error-prone. When
metadata is sought from data source contacts some are surprisingly vague about the
provenance of many of the datasets even in their own databases.
Desirable characteristics of the data for the pilot GIS are summarised in the
following list (Table 3):
Discussion
There are, based upon a simple example of collecting together existing datasets in an
environmental database for an application, many factors that need to be considered
when planning to use archival and other data of uncertain origin. Knowledge of the
datasets available, including their source, format, and quality, can provide a far firmer
basis upon which to proceed with a project. Where funds are short, it is inevitable that
one option that will be considered is the use of the existing data. This may in fact be
possible providing that the applications specialist is clearly aware of the limitations and
constraints that exist in the use of spatial and temporal data. It is important to take all
these factors into account when undertaking a similar project because it ultimately
affects what analyses are carried out, the conclusions drawn, and their potential use for
planning and decision-making.
127
QUALITY
The quality of available data varies considerably. In part, if it is archival data, this is not
surprising as methods of data collection and the equipment used have improved
considerably over time. Some data may have been surveyed by trained professionals
whilst others had been collected by amateur volunteers. Some datasets may themselves
have been previously compiled from multiple and unspecified sources in different
formats and thus are devoid of standards and are potentially more error-prone. When
metadata is sought from data source contacts some are surprisingly vague about the
provenance of many of the datasets even in their own databases.
Desirable characteristics of the data for the pilot GIS are summarised in the
following list (Table 3):
Discussion
There are, based upon a simple example of collecting together existing datasets in an
environmental database for an application, many factors that need to be considered
when planning to use archival and other data of uncertain origin. Knowledge of the
datasets available, including their source, format, and quality, can provide a far firmer
basis upon which to proceed with a project. Where funds are short, it is inevitable that
one option that will be considered is the use of the existing data. This may in fact be
possible providing that the applications specialist is clearly aware of the limitations and
constraints that exist in the use of spatial and temporal data. It is important to take all
these factors into account when undertaking a similar project because it ultimately
affects what analyses are carried out, the conclusions drawn, and their potential use for
planning and decision-making.