410
J. Raper et al.
STRUCTURING OF SPATIO-TEMPORAL DATASETS FOR MORPHODYNAMIC
STUDIES
The study of actual coastal morphodynamics requires that morphological change and
process inputs be correlated and explored for process signatures in the morphology and
lags between the timing of process energy input and form response. Such studies
could potentially show that such coastal geomorphology is chaotic: this may mean that
patterns of energy input to coastal morphology are more important that the sheer
magnitude at any given time. However, such studies depend critically on temporally
structured spatial databases so that spatio-temporal behaviour can be explored.
In the research at Scolt Head Island the methodology of Raper and
Livingstone (1995) has been put into practice. This approach called for the creation of
firstly, a low level distributed database of morphology, composition and process which
was integrated in terms of coordinate system and spatial/temporal datum, and
secondly, a high level data model allowing the user to specify spatio-temporal queries
on this data. Data collected across space in short periods of time has been stored in the
ArcView GIS as geometric layers: in figure 7a surveyed data points from September
1995 are shown together with points from January 1996. ArcView has been used to
measure distances and height differences between points at a similar position in
absolute space for the two different times: in figure 7b the two cross sections show the
profiles of the spit shoreface for the pairs of points identified by the white arrow in
figure 7b.
This high level data model allows the user to compare spatial locations at
different times (for example, by the construction of time-difference maps) or to track
the movement of spatial configurations through time (for example, by analysing slope
angle changes through space and time). The comparison of surfaces through time and
the tracking of specific features has been examined, revealing the potential of virtual
J. Raper et al.
STRUCTURING OF SPATIO-TEMPORAL DATASETS FOR MORPHODYNAMIC
STUDIES
The study of actual coastal morphodynamics requires that morphological change and
process inputs be correlated and explored for process signatures in the morphology and
lags between the timing of process energy input and form response. Such studies
could potentially show that such coastal geomorphology is chaotic: this may mean that
patterns of energy input to coastal morphology are more important that the sheer
magnitude at any given time. However, such studies depend critically on temporally
structured spatial databases so that spatio-temporal behaviour can be explored.
In the research at Scolt Head Island the methodology of Raper and
Livingstone (1995) has been put into practice. This approach called for the creation of
firstly, a low level distributed database of morphology, composition and process which
was integrated in terms of coordinate system and spatial/temporal datum, and
secondly, a high level data model allowing the user to specify spatio-temporal queries
on this data. Data collected across space in short periods of time has been stored in the
ArcView GIS as geometric layers: in figure 7a surveyed data points from September
1995 are shown together with points from January 1996. ArcView has been used to
measure distances and height differences between points at a similar position in
absolute space for the two different times: in figure 7b the two cross sections show the
profiles of the spit shoreface for the pairs of points identified by the white arrow in
figure 7b.
This high level data model allows the user to compare spatial locations at
different times (for example, by the construction of time-difference maps) or to track
the movement of spatial configurations through time (for example, by analysing slope
angle changes through space and time). The comparison of surfaces through time and
the tracking of specific features has been examined, revealing the potential of virtual