Geography Reference
In-Depth Information
Fig. 5 Supported Interaction Operators
Figure
5
provides an overview of the supported interaction operators (i.e.,
functionality) across the sample of visualization tools. The most commonly
implemented operator is
overlay
(24/25; 96 %), which allows users to toggle the
visibility of the overlay context layers shown in the display. While only nineteen
(76 %) of the evaluated visualization tools include additional overlay context
layers, the other five (20 %) tools implement overlay functionality for toggling of
the waterline/flood extent itself. Such a use of overlay for the waterline/flood extent
overcomes the aforementioned problem of obfuscating an area of interest with a
polygonal symbol, albeit the basemap and flood extent still cannot be viewed in
concert. Twenty-three (92 %) of the maps support
zoom
, or the ability to change the
map scale, and twenty-two (88 %) of the maps support
pan
, or the ability to change
the map centering, typically after zooming into the map. Also tied for the third most
common operator is
retrieve
(21/25; 84 %), or the ability to request specific details
about a map feature in the visualization. The provision of overlay, pan, zoom, and
retrieve to manipulate a multiscale basemap is increasingly common today due to
the ease in implementing these features with contemporary web mapping technol-
ogies (Roth et al.
2014
); a web map with this basic functionality often is described
informally as a
map. It therefore is not unexpected that the large majority of
evaluated visualizations support these four operators.
slippy
'
'