28 Web Mapping & Web GIS

Dr Seema Mehra Parihar

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     Learning Outcome:

 

After studying this unit you should be able :

  1. To understand the relevance of Internet in todays spatial decision making;
  2. To comprehend the importance of web Maps & web mapping;
  3. To understand Web GIS & its nuances; and
  4. To Visualise the Applications of WEB GIS

    1.  Introduction

 

Web mapping is the process of designing, implementing, generating and delivering maps on the World Wide Web and its product. While web mapping primarily deals with technological issues, web cartography additionally studies theoretic aspects: the use of web maps, the evaluation and optimization of techniques and workflows, the usability of web maps, social aspects, and more. Web GIS is similar to web mapping but with an emphasis on analysis, processing of project specific geo-data and exploratory aspects. Often the terms web GIS and web mapping are used synonymously, even if they don’t mean exactly the same. In fact, the border between web maps and web GIS is blurry.

 

2. Why is it important & urgent to understand Web Maps , Web Mapping & Web GIS?

 

i. Internet of Everything : Internet of Things (IoT) was yesterday. Today, the future is Internet of Everything. IoT is the inter-networking of physical devices, vehicles, buildings, and other items — embedded with electronics, software, sensors, actuators, and network connectivity that enable them to collect and exchange data.

 

ii. Big Data, Cloud and the Internet of Things are all parts of a continuum. It is hard to think about the Internet of Things without thinking about the Cloud, and it is hard to think about the Cloud without thinking about the analytics. As IoT becomes a buzzword, it is envisioned that the integrated network of Big Data will use advanced analytics to create actionable intelligence with predictive algorithms to program automated SMART systems with improved efficiencies.

 

iii. Multiple sensors like cameras, scanners and sensors will provide data to smart systems in every sphere of life — from cities to energy, transport, agriculture, natural resource management to health etc. So your fridge would be able to tell you it is out of milk. As you drive your car in and out of the driveway, smart lighting control will automatically turn the lights on and off to save on energy costs. Window shades will also automatically open and close based on the weather. In industries, data usage from parts would be able to predict machine breakdown, ordering a replacement automatically before a part actually breaks. Emergency services personnel will know who is in the building and where they are. In the healthcare segment, a patient’s behavior and symptoms could be monitored in real time and at relatively low costs.

 

iv. Hype is in full swing

 

v. Cynics would call it hype. But if we go by figures, the hype is in full swing. Cisco says as many as 50 billion devices will be connected to the Internet by 2020. According to Juniper Research, there will be over 285% rise in connected devices by 2020. IoT industry is set to grow to $1.9 trillion in size by 2020, as per Gartner estimates while A.T. Kearney says IoT will start to impact close to 6% of the global economy in the next four years.

 

vi. Needless to say this kind of next-generation market opportunity is pulling in tens of millions in venture funding for startups as well. In 2014 alone, over $1.6 billion was invested into IoT companies by venture capitalists.

 

2. WEB MAPS

 

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, smart phones, PDAs, GPS and other devices. 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.

 

“The use of the web as a dissemination medium for maps can be regarded as a major advancement in cartography and opens many new opportunities, such as real time maps, cheaper dissemination, more frequent and cheaper updates of data and software, personalized map content, distributed data sources and sharing of geographic information. It also implicates many challenges due to technical restrictions (low display resolution and limited bandwidth, in particular with mobile computing devices, many of which are physically small, and use slow wireless Internet connections), copyright and security issues, reliability issues and technical complexity. While the first web maps were primarily static, due to technical restrictions, today’s web maps can be fully interactive and integrate multiple media. This means that both web mapping and web cartography also have to deal with interactivity, usability and multimedia issues.

 

 

The advent of web mapping can be regarded as a major new trend in cartography. Previously, cartography was restricted to a few companies, institutes and mapping agencies, requiring expensive and complex hardware and software as well as skilled cartographers and geoinformatics engineers. With web mapping, freely available mapping technologies and geodata potentially allow every skilled person to produce web maps, with expensive geodata and technical complexity (data harmonization, missing standards) being two of the remaining barriers preventing web mapping from fully going mainstream. The cheap and easy transfer of geodata across the internet allows the integration of distributed data sources, opening opportunities that go beyond the possibilities of disjoint data storage. Everyone with minimal knowhow and infrastructure can become a geodata provider. These facts can be regarded both as an advantage and a disadvantage. While it allows everyone to produce maps and considerably enlarges the audience, it also puts geodata in the hands of untrained people who potentially violate cartographic and geographic principles and introduce flaws during the preparation, analysis and presentation of geographic and cartographic data.

 

3)  Types of Web Maps

‘

     A first classification of web maps has been made by Kraak. He distinguished static and dynamic web maps and further distinguished interactive and view only web maps. However, today in the light of an increased number of different web map types, this classification needs some revision. Today, there are additional possibilities regarding distributed data sources, collaborative maps, personalized maps, etc

 

a)  Analytic Web Maps

 

These web maps offer GIS analysis, either with geodata provided, or with geodata uploaded by the map user. As already mentioned, the borderline between analytic web maps and web GIS is blurry. Often, parts of the analysis are carried out by a server side GIS and the client displays the result of the analysis. As web clients gain more and more capabilities, this task sharing may gradually shift.

 

b) 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, communication patterns, social studies projects, and for college life, etc.).

 

c) Collaborative Web Maps

 

Collaborative maps are still new, immature and complex to implement, but show a lot of potential. The method parallels the Wikipedia project 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. Some collaborative map projects:

 

Google Map Maker (Till March 31, 2017)—Google Maps OpenStreetMap

 

WikiMapia

 

meta:Maps – survey of Wikimedia map proposals on Wikipedia:Meta

 

Figure 1: Open Street  Web Map

 

 

Box 1: An Example of Collaborative Web

 

Map Project: Google Map Maker

 

      Google Map Maker officially closed on March 31, 2017, and many of its features are being integrated into Google Maps.Since 2008, the Google Map Maker community has edited and moderated millions of features to improve the Google Maps experience. To make it easier for all Google Maps users to contribute changes to the map, we’ve started to graduate functionality from Map Maker to Google Maps on both desktop and mobile.

    Key editing features currently available in Google Maps include:

 

– Add a Place

-Edit Info About a Place

-Share info about a Place

-Moderate Edits

-View the Status of your Edits

-Edit Road segments

 

    d) Customised Web Maps

 

Web maps in this category are usually more complex web mapping systems that offer APIs for reuse in other people’s web pages and products. Example for such a system with an API for reuse is the Open Layers Framework, Yahoo! Maps and Google Maps.

 

e) Distributed Web Maps

 

These are maps created from a distributed data source. The WMS protocol offers a standardised method to access maps on other servers. WMS servers can collect these different sources, reproject the map layers, if necessary, and send them back as a combined image containing all requested map layers. One server may offer a topographic base map, while other servers may offer thematic layers.

 

f) 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 self written software. Some applications refer to depictions as hyper maps. One of the examples is- Bhoosampada by Indian Space Research Organizations.

 

g) Hyper Maps

 

Any approach offering the planar presentation of a portion of an n-dimensional orthogonal web map structure with the option to choose the axes for depiction from the dimensions.

 

h) Interactive Web Maps

 

Interactivity is one of the major advantages of screen based maps and web maps. It helps to compensate for the disadvantages of screen and web maps. Interactivity helps to explore maps, change map parameters, navigate and interact with the map, reveal additional information, link to other resources, and much more. Technically, it is achieved through the combination of events, scripting and DOM manipulations. See section on Client Side Technologies.

 

4) Advantages of Web Maps

 

1. Web maps can easily deliver up to date information. If maps are generated automatically from databases, they can display information in almost real-time. They don’t need to be printed, mastered and distributed. Examples:

 

o A map displaying election results, as soon as the election results become available.

 

o A map displaying the traffic situation near real-time by using traffic data collected by sensor networks.

 

o A map showing the current locations of mass transit vehicles such as buses or trains, allowing patrons to minimize their waiting time at stops or stations, or be aware of delays in service.

 

o  Weather maps, such as NEXRAD.

 

   2. Software and hardware infrastructure for web maps is cheap. Web server hardware is cheaply available and many open source tools exist for producing web maps.

 

3. Product updates can easily be distributed. Because web maps distribute both logic and data with each request or loading, product updates can happen every time the web user reloads the application. In traditional cartography, when dealing with printed maps or interactive maps distributed on offline media (CD, DVD, etc.), a map update caused serious efforts, triggering a reprint or remastering as well as a redistribution of the media. With web maps, data and product updates are easier, cheaper, and faster, and can occur more often.

 

4.They work across browsers and operating systems. If web maps are implemented based on open standards, the underlying operating system and browser do not matter.

 

5. Web maps can combine distributed data sources. Using open standards and documented APIs one can integrate (mash up) different data sources, if the projection system, map scale and data quality match. The use of centralized data sources removes the burden for individual organizations to maintain copies of the same data sets. The downside is that one has to rely on and trust the external data sources.

 

6.Web maps allow for personalization. By using user profiles, personal filters and personal styling and symbolization, users can configure and design their own maps, if the web mapping systems supports personalization. Accessibility issues can be treated in the same way. If users can store their favourite colors and patterns they can avoid color combinations they can’t easily distinguish (e.g. due to color blindness).

 

Figure 2: How to use Land cover data as a Water Quality Indicator , ESRI-2017

 

 

7. Web maps enable collaborative mapping. Similar to the Wikipedia project, web mapping technologies, such as DHTML/Ajax, SVG, Java, Adobe Flash, etc. enable distributed data acquisition and collaborative efforts. Examples for such projects are the OpenStreetMap project or the Google Earth community. As with other open projects, quality assurance is very important, however!

 

8. Web maps support hyperlinking to other information on the web. Just like any other web page or a wiki, web maps can act like an index to other information on the web. Any sensitive area in a map, a label text, etc. can provide hyperlinks to additional information. As an example a map showing public transport options can directly link to the corresponding section in the online train time table.

 

It is easy to integrate multimedia in and with web maps. Current web browsers support the playback of video, audio and animation (SVG, SWF, Quicktime, and other multimedi

 

5. What is Web GIS?

 

     “Web GIS is a type of distributed information system, comprising at least a server and a client, where the server is a GISserver and the client is a web browser, desktop application, or mobile application. In its simplest form, web GIS can bedefined as any GIS that uses web technology to communicate between a server and a client, ESRI,2016”.

 

“The term WebGIS is being tossed around all over the place right now but thetrue meaning of the term may be very different than what you understand it to be. WebGIS explained In its simplest form, web GIS can be any GIS that uses web technology to communicate between a server and a client ,(SSP,2017”.))

 

“The following are  few key elements essential to web GIS (Mathelle,2009):

  1. The server has a URL so that clients can find it on the web.
  2. The client relies on HTTP specifications to send requests to the server.
  3. The server performs the requested GIS operations and sends responses to the client via HTTP.
  4. The format of the response sent to the client can be in many formats, such as HTML, binary image, XML (ExtensibleMarkup Language), or JSON (JavaScript Object Notation”

 

In the document titled “A framework for deploying web GIS applications” (source: URL1) it has been pointed out that there are 5 essential elements in every web GIS app. These include:

 

i. a web application

ii. digital basemaps

iii. operational layers

iv. tasks and tools

v. one or more geodatabase

 

6. The web GIS advantage

 

      By utilizing the Internet to access information over the web without regard to how far apart the server and client might be from each other, web GIS introduces distinct advantages over traditional desktop GIS, including the following:

 

i. It is borderless & have A global reach: Any web GIS applications can be presented to the world, and the world can access them from their computers or mobile devices. The global nature of web GIS is inherited from HTTP, which is broadly supported. Almost all organizations open their firewalls at certain network ports to allow HTTP requests and responses to go through their local network, thus increasing accessibility.

 

ii. A large number of users: In general, a traditional desktop GIS is used by only one user at a time, while a web GIS can be used by dozens or hundreds of users simultaneously. Thus, web GIS requires much higher performance and scalability than desktop GIS.

 

iii. Better cross-platform capability: The majority of web GIS clients are web browsers: Internet Explorer, Mozilla Firefox, Apple Safari, Google Chrome, and so on. Because these web browsers largely comply with HTML andJavaScript standards, web GIS that relies on HTML clients will typically support different operating systems such as Microsoft Windows, Linux, and Apple Mac OS.

 

iv. Low cost as averaged by the number of users: The vast majority of Internet content is free of charge to end users, and this is true of web GIS. Generally, you do not need to buy software or pay to use web GIS. Organizations that need to provide GIS capabilities to many users can also minimize their costs through web GIS. Instead of buying and setting up desktop GIS for every user, an organization can set up just one web GIS, and this single system can be shared by many users: from home, at work, or in the field.

 

v. Easy to use: Desktop GIS is intended for professional users with months of training and experience in GIS. Web GIS is intended for a broad audience, including public users who may know nothing about GIS. They expect web GIS to be as easy as using a regular website. Web GIS is commonly designed for simplicity, intuition, and convenience, making it typically much easier to use than desktop GIS.

 

vi. Unified updates: For desktop GIS to be updated to a new version, the update needs to be installed on everycomputer. For web GIS, one update works for all clients. This ease of maintenance makes web GIS a good fit for delivering real-time information.

 

vii. Diverse applications: Unlike desktop GIS, which is limited to a certain number of GIS professionals, web GIS can be used by everyone in an enterprise as well as the public at large. This broad audience has diverse demands.

 

Figure3: ACME Insurance Web Mapping , IBM,2017

 

 

Applications such as mapping celebrity homes, tagging personal photos, locating friends, and displaying Wi-Fi hot spots are a few of the many current examples of web GIS.

 

These characteristics reveal both the advantages and challenges facing web GIS. For example, the easy-to-use nature ofweb GIS stimulates public participation, but it also reminds you to take into account Internet users who have no GIS background. Conversely, supporting a large number of users requires web GIS to be scalable

 

 

6. Data store scenarios for Image services when Publishing Web Data

 

“Following document is based on using ArcGIS 10.5 on Windows. We all know that how you organize and register your data with the server will impact whether or not the data needs to be packaged and copied to the server when publishing. When you publish, you want to be sure that the server has access to all of the content managed by the mosaic dataset; so you must set the data store and prepare the mosaic dataset correctly. Each scenario below will expand on this issue specifically when using mosaic datasets since a mosaic dataset references data that can reside anywhere (as long as it can be read).

 

Scenario 1: All data is on a shared location

 

This is probably the best data organizational structure.

 

 

Scenario 2: All data is duplicated

 

In this scenario, your data is stored in two locations: one accessed by the server and one you connect to in the Catalog window.

 

 

Scenario 3: There is no registered data location

 

Like scenario 1, this also is uncomplicated because you don’t have to worry about where any of your data is and if the server can or can’t access it or the correct version of it. In this scenario, all the data is packaged and moved to the server when it’s published.

 

 

Scenario 4: Only the source data is in a registered location

    In this scenario, the source data location is not the same location as the mosaic dataset. This source data location can be shared or duplicated.(ESRI,10.5 document)”

 

7. Example of Web GIS :India –WRIS

 

 

“India-WRIS Web GIS aims as a ‘Single Window’ solution for comprehensive, authoritative and consistent data & information of India’s water resources along with allied natural resources in a standardized national GIS framework with tools to search, access, visualize, understand and analyze the data for assessment, monitoring, planning, development and finally Integrated Water Resources Management (IWRM). The project has been jointly undertaken by CWC, MoWR and NRSC, ISRO, DoS in year 2009. Based on the requirements and data availability, the India-WRIS Web-GIS has 12 major info systems, 36 sub info systems including 95 layers, classified under 5 major groups 1) watershed atlas, 2) administrative layers, 3) water resources projects, 4) thematic layers and 5) environmental data. The main layers developed under India-WRIS are Basin, Sub Basin, Watershed, River, water-body, urban and rural population extents, Dams, Barrage/weir/anicut, canals and command boundaries etc. These spatial layers have large number of attribute data of 5-100 years depending upon the theme. All unclassified data of CWC’s HO stations and CGWB ground water data is available in the portal for free download. The information system has dedicated Sub-Info systems for various components of surface water, ground water, hydro-met observations, water quality, snow cover, inter-basin transfer links, land resources, socio-economic parameters as well as infrastructure and other administrative layers.

 

The India-WRIS WebGIS has special modules for live telemetry data and reservoir module with daily level and storage data of reservoirs. Automatic map generation and automatic report generation Module can cater the need of area specific maps and reports. Customized maps can be generated using create your WRIS Module. India-WRIS Web-GIS has all the map viewing and other capabilities including saving/printing facilities.

 

WRIS Website

 

Surface Water Quality Sub-InfoSystem

 

Ground water Quality Sub-InfoSystem

 

HO Sub-InfoSystem

 

Reservoir Module

 

Telemetry Module

 

Snow Cover/Glacier Sub-InfoSystem, WRIS,2017”

 

 

Summary

 

Internet of Things (IoT) was yesterday. Today, the future is Internet of Everything. It is important for us to learn and use them.Five essential elements in every web GIS app. include:a web application; digital basemaps; operational layers; tasks and tools. There is a thin line between Web mapping & Web GIS and we need to understand them and use the available information for decision making judiciously. One good example in this case has been India-WRIS Web GIS project , jointly undertaken by CWC, MoWR and NRSC, ISRO, DoS in year 2009. Based on the requirements and data availability, the India-WRIS Web-GIS has 12 major info systems, 36 sub info systems including 95 layers, classified under 5 major groups 1) watershed atlas, 2) administrative layers, 3) water resources projects, 4) thematic layers and 5) environmental data. The example illustrates that we need to Use Web GIS correctly ,it is not a hype & it is borderless with global reach. Applications are certainly continuously expanding. Let us Use them!

 

you can view video on Web Mapping & Web GIS

 

References