Using Remotely Sensed Imagery for CZM
475
The Importance of Geo-Spatial Information in Environmental Management
From the earliest times, maps (a source of geographic information) have been used to
essentially record data about the world in which we live. Couclelis (1998) argues that
geographic data is used by people because the geographic world is a generally
accessible and comprehensive realm of experience, offering "a complete array of forms,
colors, textures and patterns" as well as "a wide range of basic sensorimotor, cognitive
and affective experiences" (p. 209) and because things that have the look and feel of
geographic space make it easier for people to understand.
The use of geo-spatial data appears to be a natural human instinct and we all
make use of geographic data and information on a daily basis, be it maps for directions,
plans for building, and ultimately, our own mental maps of our surroundings (Green and
King, 1998). It is, therefore, not surprising that geography and geographical tools have
become essential in our day-to-day living, decision-making, and management of the
environment.
Using Remote Sensing to Collect Environmental Data
Remote sensing has witnessed a rapid development since the late 1970s, and is now
frequently used as a source of environmental data. A much vaunted advantage of remote
sensing, particularly satellite remote sensing, is that data from parts of the
electromagnetic spectrum other than solely the visible, such as thermal, microwave and
near-infrared (which cannot be seen by the human eye) can be utilised. This allows
information to be gathered about the surface features that may otherwise go unnoticed
(King, 1998).
Despite this, it is still perhaps the spatial resolution of different remotely
sensed imagery that is of greatest importance in the context of geo-spatial data. This is
because the spatial resolution of an image ultimately controls the amount of detail that is
shown, and the information that may be extracted from it.
Scale and Spatial Resolution in Remote Sensing
Before defining scale and resolution, it is important to understand the distinction
between data and information, so that the controls scale and resolution have on
information content may be fully comprehended. A typical definition offered by
Heywood et al., (1998) and Olivieri et al., (1995) is that data is a set of measurements
describing an object or process, whereas information is data that has been analysed and
given context. On the other hand, Couclelis (1998) suggests that data is something that
can be "automatically manipulated and processed by a machine, whereas information
presupposes the involvement of a cognitive agent" (p.211), or in other words, someone
recognising information held in the data.
Scale and resolution, like data and information, are closely related terms
(although they have different meanings). When we think of scale in relation to geospatial data, maps frequently come to mind. Maps take up less physical area than they
represent. The reduction in areal coverage is reflected by the scale of the map, which
indicates the number of metric units on the ground that are represented by a unit on the
475
The Importance of Geo-Spatial Information in Environmental Management
From the earliest times, maps (a source of geographic information) have been used to
essentially record data about the world in which we live. Couclelis (1998) argues that
geographic data is used by people because the geographic world is a generally
accessible and comprehensive realm of experience, offering "a complete array of forms,
colors, textures and patterns" as well as "a wide range of basic sensorimotor, cognitive
and affective experiences" (p. 209) and because things that have the look and feel of
geographic space make it easier for people to understand.
The use of geo-spatial data appears to be a natural human instinct and we all
make use of geographic data and information on a daily basis, be it maps for directions,
plans for building, and ultimately, our own mental maps of our surroundings (Green and
King, 1998). It is, therefore, not surprising that geography and geographical tools have
become essential in our day-to-day living, decision-making, and management of the
environment.
Using Remote Sensing to Collect Environmental Data
Remote sensing has witnessed a rapid development since the late 1970s, and is now
frequently used as a source of environmental data. A much vaunted advantage of remote
sensing, particularly satellite remote sensing, is that data from parts of the
electromagnetic spectrum other than solely the visible, such as thermal, microwave and
near-infrared (which cannot be seen by the human eye) can be utilised. This allows
information to be gathered about the surface features that may otherwise go unnoticed
(King, 1998).
Despite this, it is still perhaps the spatial resolution of different remotely
sensed imagery that is of greatest importance in the context of geo-spatial data. This is
because the spatial resolution of an image ultimately controls the amount of detail that is
shown, and the information that may be extracted from it.
Scale and Spatial Resolution in Remote Sensing
Before defining scale and resolution, it is important to understand the distinction
between data and information, so that the controls scale and resolution have on
information content may be fully comprehended. A typical definition offered by
Heywood et al., (1998) and Olivieri et al., (1995) is that data is a set of measurements
describing an object or process, whereas information is data that has been analysed and
given context. On the other hand, Couclelis (1998) suggests that data is something that
can be "automatically manipulated and processed by a machine, whereas information
presupposes the involvement of a cognitive agent" (p.211), or in other words, someone
recognising information held in the data.
Scale and resolution, like data and information, are closely related terms
(although they have different meanings). When we think of scale in relation to geospatial data, maps frequently come to mind. Maps take up less physical area than they
represent. The reduction in areal coverage is reflected by the scale of the map, which
indicates the number of metric units on the ground that are represented by a unit on the