Geoscience Reference
In-Depth Information
Web maps included Xerox PARC Map Viewer followed by the Tiger Mapping Service, MapQuest
and Multimap. Such services were limited to information preloaded by the provider and offered
little in the way of spatial analysis. The second generation of Web maps in the mid-1990s were
built upon then novel technologies such as applets (e.g. Java) and component-oriented Web tools
(e.g. ActiveX) such as ESRI ArcIMS and now ArcGIS Server. Such technology enabled the
deployment of Web Mapping Services (WMS) on local Web servers. According to the Open
Geospatial Consortium (OGC), the WMS standard (2000) focuses on three primary functions:
'produce a map', 'answer basic queries about the content of the map' and 'tell other programs
what maps it can produce and which of those can be queried further'. Such services allowed
browsing, searching, downloading and basic editing of geographical information (see Simao et
al., 2009 for such a sample application). Such Web mapping standards allowed people to create
maps from the aggregation of multiple geographically distributed data sources. However, such
applications largely remained in the hands of GIS experts due to the technical complexity of the
standards and availability of OGC-compliant software and services (Haklay et al., 2008). Some
have referred to such services as GeoWeb 1.0 (Maguire, 2006).
Following Plewe (2007), the next two paradigms evolved almost simultaneously. Moreover,
these paradigms opened the way for the general public to produce and distribute geographical
information - for better or worse (Sui, 2008). The third paradigm of Web mapping delivered a more
interactive map browsing by utilising technologies such as JavaScript and XML. This has been
made possible through the availability of application programming interfaces (APIs), which provide
an application-agnostic framework to access geographical information. This framework has been
particularly valuable and popular for the creation of mashups* for retrieving, querying and display-
ing geographical information on maps. For example, the release of the Google Maps API enables
users to mix Google stream-based data with other spatially referenced material. The release of this
API in 2005 changed the GeoWeb as it gave the masses easy access to unprecedented amounts of
geographical information (Hudson-Smith and Crooks, 2009) and promoted the creation of numer-
ous GeoWeb applications. For example, 2 years after its release, the Google Maps API was used
in over 50,000 websites (Tran, 2007). Such a dramatic increase in the use of Web-based mapping
services could not have been supported by the GeoWeb 1.0 paradigm due to the high technical entry
level needed to deploy WMS and the high cost with respect to setting up such a service (Haklay
et al., 2008). Through the combination of relatively easy-to-use APIs and the mashup concept, data
can be quickly transformed into consumable maps and served as bespoke applications. Examples
include but are not limited to mashups covering themes such as devastation caused by hurricanes
(Miller, 2006) or damage caused by floods (e.g. Hudson-Smith et al., 2009b) and to that of the
destruction caused by earthquakes (Zook et al., 2010).
Initially such mashups were focused on mapping point data (e.g. UK floods in 2007; see Hudson-
Smith et al., 2009b) even if they were used to summarise areal distributions. Choropleth maps in
mashups were not initially available, which lead researchers to create tools for choropleth map gen-
eration such as those initially developed at the Centre for Advanced Spatial Analysis (see Hudson-
Smith et al., 2009b) or Geocommons (2012). For example, in Figure 4.2, we illustrate the graphical
user interface (GUI) of the London Profiler website, which is a mashup of various types of datasets
from the UK census and other sources in the form of choropleth maps, displayed on top of Google
Maps using the Google Maps API (see Gibin et al., 2008 for more information). However, such
mashups had limited spatial analysis capabilities compared to desktop GIS functionalities or Web
services that are based on a fully fledged GIS engine (e.g. the ArcGIS Server).
* As a further indicator of the effects of Web 2.0 on geospatial capabilities, the term mashup itself crossed over to geospa-
tial technology from popular culture: DJ Danger Mouse first used the term to describe the mixing together of musical
tracks on his Grey Album. The term now refers to websites that weave data from different sources into a new integrated
single user service (Hof, 2005).
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