ADVANCED LEGENDS FOR INTERACTIVE DYNAMIC MAPS
T Midtbo
Division of Geomatics, NTNU
terjem@ntnu.no
10-12 years ago the
majority of maps, either on paper or in electronic media, usually were static
and included few interactive operations. The legend describing the symbols on
the map was, with few exceptions, located outside the map itself. With the
introduction of the Internet and the World Wide Web (WWW) we have experienced
new types of maps which enable more interactivity, more dynamic changes and the
incorporation of sound together with the visual presentation. Today thousands
of small interactive cartographic products can be found on the Web around the
world. However, compared to more traditional cartography, the evolution of
small map applications on web are still in an early phase.
Electronic maps open for
more animations and interactivity in the map itself. At the same time there are
more possibilities for making closer connection between the map and the legend.
Peterson (1999) introduces the term “active legend” for the use in interactive
cartographic animations. In Peterson (1999) the legend works as a control panel
for the map itself. Van den Worm (2001) discusses some more methods for the use
of legends in small map applications and Midtbø (2003) gives others
examples on the use of active legends. In a dynamic presentation of a thematic
map, the symbols in the map may change during the animation and make it more
difficult for the map reader use keep track of the information and compare it
with the legend. This paper looks closer into methods for the active use of the
legends on thematic maps. It shows how legends can split and moved around in
the application to make it easier for the map reader to compare values in the
legend with the symbols on the map. At the same time, operations in the map can
be controlled by the legends. The paper also gives examples on how sound can be
used to emphasize the connection between the legend and the thematic symbols on
the map.
Midtbø, T (2003).
“Multivariable “seeing maps” trough interactive animations”, Proceedings of the 21th International Cartographic Conference,
10-16 August 2003, Durban, South Africa.
van den Worm, J. (2001). “Web map design in practice”,
in Kraak and Brown (eds.), Web
Cartography, Taylor & Francis
Inc. London, 2001.
Peterson, M.P. (1999). “Active legends for interactive
cartographic animation”, International
Journal of Geographical Information
System, 13(4):375-383.