Web GIS

Introduction :

Web GIS is the combination of the web and GIS. The web removed the constraint of distance in cyberspace, and thus allows people the freedom to interact with GIS apps globally and access information almost instantly. Web GIS uses web technologies, including, but not limited to, Hypertext Transfer Protocol (HTTP), Hypertext Markup Language (HTML), Uniform Resource Locator (URL), JavaScript, Web Graphics Library (WebGL), WebSocket, and more.

The first operational GIS was developed in the 1960s by Roger Tomlinson. Since then, GIS has continuously evolved from a local file-based single computer system to a central database-based client/server system, often with multiple servers and many more client computers. The invention of the internet in the late 1950s and the World Wide Web in the early 1990s laid the foundation for an evolutionary leap toward Web GIS. In 1993, the Xerox Corporation’s Palo Alto Research Center (PARC) developed a mapping web page, which marked the origin of Web GIS. In the 2000s, Web GIS evolved into a new generation—a system of distributed web services you can access in the cloud, as represented by the Esri ArcGIS platform.

Web GIS can be implemented in the cloud (using ArcGIS Online), on-premises (using ArcGIS Server), or more typically as a hybrid combination, leveraging the best of both worlds.
Web GIS isn’t new, in fact it’s been evolving for a long while. But we’ve reached, actually passed, a tipping point where innovation in GIS and related technologies have made Web GIS not only possible, but essential.

Here are a few key elements essential to web GIS:

v  1. The server has a URL so that clients can find it on the web.

v  2. The client relies on HTTP specifications to send requests to the server.

v  3. The server performs the requested GIS operations and sends responses to the client via HTTP.

v 4. The format of the response sent to the client can be in many formats, such as HTML, binary image, XML (Extensible Markup Language), or JSON (JavaScript Object Notation).

Application :

 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

1. Mapping/ Visualization and query (attribute or spatial).

2. Collaborative collection of geospatial information.

3. Geospatial analysis: measurement, optimal driving path, routing, pollution dispersion modeling, retail site selection.

4. WebGIS as a new business model and a new type of commodity. Location: specific advertising and branding based on mapping. E.g.google.map.

5. GIS application is an engaging and powerful tool for designing and planning government projects like flood managemet, forest mapping and natural disaster.

6. WebGIS technology is used in geosciences research collaboration.

7. WebGIS in daily life: location based service(LBS) supported by mobile web, smartphones and tablets.LBS include services to identify a location of a person or object, such as discovering the nearest atm, restaurant, shops and hotels etc. LBS also includes parcel tracking and vehicle tracking services.

8. Global reach: you can share your geographic information easily within your organization and with people all over the world.

9.  Large number of users: you can share your app with dozens, or even millions, of users supported by the scalable cloud technology.

10. Low cost per user: the cost of building one Web GIS app is often cheaper than building a stand-alone desktop solution and installing it for every user.

11. Better cross-platform capabilities: web apps, especially those built with JavaScript, can run on desktop and mobile browsers running a wide range of operating systems, from Windows, Mac OS, and Linux to iOS, Android, and Windows Phone.

12. Easy to use: Web GIS apps typically incorporate simplicity, intuition, and convenience into their design. Therefore, public users can use these apps without having prior knowledge.

13. Easy to maintain: web clients can benefit from the latest program and data updates each time they access a web app. The web administrator does not have to update all the clients separately.

 

Recent Trends in WebGIS :

The web continues to have an enormous impact on how we practice GIS and how we apply geospatial tools and capabilities to support our workflows and solve problems. It has fundamentally changed everything we do, and how we think.

1. Analysis:- Analysis is the heart and soul of true Web GIS. Hosted analysis and geoprocessing tools continue to grow in both number and capabilities. GIS professionals are familiar with these tools, and use them every day. But what’s trending here is that these tools can be used by anyone in an ArcGIS organization, and they are presented in ways that make them easy to understand and apply to common geospatial problems.

     2. 3D:- Web GIS has enabled 3D to grow across the entire platform. For example, It provide and integrated platform for 2D/3D visualization, analysis, and publishing. The 3D Analyst delivers advanced analysis supporting 3D workflows. Web scenes make it possible for anyone to view scenes in a browser.

      3. Data source goes from static to real time and spatial temporal big data:- Many elements in Web GIS are of a real-time nature, such as the incidents immediately reported by field crews or citizens using mobile devices, the concurrent measurements from sensor net-works and smart cities. This massive amount of data presents challenges in real-time intake,processing, analysis, visualization, and storage. Such products and research allow Web GIS tomeet the requirements of the Sensor Web interface and the Internet of Things (IoT).

4.Web GIS becomes smarter and more intelligent:- Map visualization is the first step toward data analysis. Online mapping becomes smart today. Smart Mapping can analyze the data automatically and suggest the best mapping styleand the best defaults. This can help users, experts or novice, create beautiful and informative maps quickly. Web GIS goes far beyond mapping.

 

   5. Portal technology is
becoming essential:- The word “portal” means gate
or entrance. It was adopted in the mid-1990s to form new termssuch as “web
portals,” referring to websites that serve as the gateway to other websites.
Geopor-tals are gateways to geospatial information. They serve as the gateway
or bridge between Web GISservers and clients. Portals have become a core
component of Web GIS technology.

 

    6. Cloud GIS accepted as the primary way to deliver GIS functions and ready-to-use contents:- Cloud GIS, utilizing public and private cloud computing to provide GIS software and contents,has become the primary way to deliver GIS, not just functions, but also contents. Because of the vast contents and functions available from cloud GIS, the flexible pay-as-you-go or subscription-pricing model, and the reduced complexity and increased availability of services.

 Component

   

i. Data component:

Each GIS application depends on a strong geospatial data management framework that can hold the information used to support your application. This can be one or more geodatabases, a collection of shapefiles, various tabular databases and spreadsheets, CAD files, design files, imagery, HTML web pages, and so forth.

There is a strong focus in the GIS professional community on investing in and building high-quality geographic information. The answers you derive from your GIS can be no better than the quality of the information contained in your geodatabase. GIS datasets must be compiled in unison, harmonized, and integrated to fit together in a geographic framework. Many GIS users invest heavily in the creation and maintenance of their geospatial databases. These information stores are of immense value in addressing a broad range of questions. Strong geographic data becomes more critical when you want to do more than display observations on a basemap.

ii. GIS component:

A GIS basically consists of Hardware, Software, data and users. Seeing the evolution among these components over the years is interesting. In 1960s and 1970s these components were joined together in one computer. Later distributed GIS emerged with the adoption of a local area network (LAN). Using distributed GIS, these components no longer needed to be located together, instead the components could be in separate buildings long distances from each other. With the development of Web GIS these components are now separated farther distances than before; GIS users sitting on one side of the globe can access a server located on the other side of the globe.

 

iii.  Server-client component:

Web GIS is a type of distributed information system, comprising at least a server and a client, where the server is a GIS server and the client is a web browser, desktop application, or mobile application. In its simplest form, web GIS can be defined as any GIS that use web technology to communicate between a server and a client.

Here are a few key elements essential to web GIS:

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