Geography Reference
In-Depth Information
to the pervasiveness of AJAX and the increased emphasis on responsive design
between desktop and mobile devices (Muehlenhaus
2013
). The FlashPlayer plugin
is not supported by mobile devices, meaning the seven tools developed in Flash or
Flex cannot be loaded on a smartphone or tablet (Fig.
6
, final column). Redevel-
opment of the second version of the Sea Level Rise Viewer from the ArcGIS Flex
API to the Leaflet open source library is indicative of this broad transition in web
mapping technologies from proprietary plugins to modern web standards.
Of the eighteen tools leveraging modern web standards, thirteen (52 %) use the
Google Maps JavaScript API, seven (28 %) use the ArcGIS JavaScript API, two
(n
¼
8 %) use open source solutions (Leaflet, OpenLayers), and one (n
¼
1) uses
MetaCarta. There is an emerging and active community of open source web map
developers contributing their source code to the public commons for reuse. While
open source solutions historically have suffered from poorer stability over time,
they have the advantages of incorporating innovations more quickly into their code
base and are free or near free to use. The choice of the open source library Leaflet
for the second version of the Sea Level Rise Viewer is particularly intriguing, and
likely fruitful. A recent study by Roth et al. (
2014
) charting the parallel develop-
ments of the same web map in four distinct web mapping technologies (the Google
Maps JavaScript API, D3, Leaflet, and OpenLayers) found that Leaflet was able to
produce a web map of comparable functionality to the web map leveraging the
Google Maps JavaScript API, but resulted in a much more satisfying development
experience given the openness and extensibility of the code repository. The ArcGIS
JavaScript API remains a viable option, particularly when the GIS functionality
provided by the ArcGIS suite is needed.
Finally, only the Flood Map tool is explicitly
location-aware
, drawing on the
user
s IP location to recenter the map to his or her current position. Overall, this
may be a missed opportunity, as users are increasingly encountering web maps that
are updated to their specific use context (e.g., their geographic location, their past
interactions, etc.). However, there may be privacy or accountability concerns
explaining the lack of location-aware technologies in water level visualization.
'
Conclusion and Outlook
This paper provides a functional and technological comparison of map-based
water level visualization tools to inform the design of the NOAA Lake Level
Viewer. A competitive analysis of twenty-five (n
25) visualization tools
was conducted according to criteria related to the representation or interaction
design of the evaluated tools: (1a) variation in the waterline or flood extent
symbolization, (1b) variation in included uncertainty information and un-
certainty symbolization, (1c) variation in the provided basemaps and overlay
layers, (2a) variation in the supported interaction operators, and (2b) variation
in the underlying web mapping technology.
¼
(continued)
