Web mapping is the process of designing, implementing, generating and delivering maps on the World Wide Web and its product. Web maps are often a presentation media in web GIS and web maps are increasingly gaining analytical capabilities.
A special case of web maps are mobile maps, displayed on mobile computing devices, such as mobile phones, smartphones, PDAs and GPS. If the maps on these devices are displayed by a mobile web browser or web user agent, they can be regarded as mobile web maps. If the mobile web maps also display context and location sensitive information, such as points of interest, the term Location-based services is frequently used.
A range of free software to generate maps has also been generated, alongside proprietary tools like ArcGIS. As a result, the barrier to entry for creating maps on the web has shifted from that of the paper atlas and other traditional cartography.
Types of Web Maps
Analytic Web Maps
These web maps offer GIS analysis, either with geodata provided, or with geodata uploaded by the map user. Often, parts of the analysis are carried out by a serverside GIS and the client displays the result of the analysis. As web clients gain more and more capabilities, this task sharing may gradually shift.
Animated Web Maps
Animated Maps show changes in the map over time by animating one of the graphical or temporal variables. Various data and multimedia formats and technologies allow the display of animated web maps: SVG, Adobe Flash, Java, Quicktime, etc., also with varying degrees of interaction. Examples for animated web maps are weather maps, maps displaying dynamic natural or other phenomena (such as water currents, wind patterns, traffic flow, trade flow, social studies projects, communication patterns, etc.).
Collaborative Web Maps
Collaborative maps are still new, immature and complex to implement, but show a lot of potential. It is where various people collaborate to create and improve maps on the web. Technically, an application allowing simultaneous editing across the web would have to ensure that geometric features being edited by one person are locked, so they can't be edited by other persons at the same time. Also, a minimal quality check would have to be made, before data goes public.
Dynamically Created Web Maps
These maps are created on demand each time the user reloads the webpages, often from dynamic data sources, such as databases. The webserver generates the map using a web map server or a self written software.
Online Atlases
Atlas projects often went through a renaissance when they made a transition to a web based project. In the past, atlas projects often suffered from expensive map production, small circulation and limited audience. Updates were expensive to produce and took a long time until they hit the public. Many atlas projects, after moving to the web, can now reach a wider audience, produce cheaper, provide a larger number of maps and map types and integrate with and benefit from other web resources. Some atlases even ceased their printed editions after going online, sometimes offering printing on demand features from the online edition.
Realtime Web Maps
Realtime maps show the situation of a phenomenon in close to realtime (only a few seconds or minutes delay). Data is collected by sensors and the maps are generated or updated at regular intervals or immediately on demand. Examples are weather maps, traffic maps or vehicle monitoring systems. These are commonly used in handheld devices and GPS equipped vehicles.
Static Web Maps
Static web pages are view only with no animation and interactivity. They are only created once, often manually and infrequently updated. Typical graphics formats for static web maps are PNG, JPEG, GIF, or TIFF (e.g., drg) for raster files, SVG, PDF or SWF for vector files. Often, these maps are scanned paper maps and had not been designed as screen maps. Paper maps have a much higher resolution and information density than typical computer displays of the same physical size, and might be unreadable when displayed on screens at the wrong resolution.