ArcGIS Web GIS platform coevolves with geographic information science and information technology.
Web GIS has exemplified the following evolution of stages and trends in technologies:
From closed websites to open geospatial web services
Early Web GIS applications were developed as independent websites. These websites were isolated from each other. It was difficult to share information and functions between them, and difficult to remix the websites to create new applications. In the later 1990s, web services technology was conceived. Web services can be thought of as building blocks that can be shared and remixed in versatile ways for building web applications. The GIS industry adopted the concept of web services in manufacturing Web GIS products. For example, ArcGIS Web GIS products fully support the web services architecture: server side provides ready-to-use services and allows users to create their own services; client side can consume and combine these services to create applications.
From one-way to two-way information flow
Early Web GIS products and applications mainly supported one-way information flow, which was from server side to client side. Users were merely the receivers of information. As time entered the new century, user-generated content (UGC) became a significant phenomenon and created a reversed information flow, from client side to server side. Volunteered geographic information (VGI) is the UGC of a geospatial nature and this was supported by Web GIS products. For example, ArcGIS facilitates VGI through editable feature services and hosted feature layers, mobile GIS apps, and browser-based apps. Users can view maps and perform queries, as well as conduct field surveys, collect data, and report events they saw. VGI provides unique values and perspectives to global observation, information sharing, and public engagement.
Portal technology is becoming essential
The word “portal” means gate or entrance. It was adopted in the mid-1990s to form new terms such as “web portals,” referring to websites that serve as the gateway to other websites. Geoportals are gateways to geospatial information. They serve as the gateway or bridge between Web GIS servers and clients. Portals have become a core component of Web GIS technology. For example, ArcGIS Online and Portal for ArcGIS have geoportal capabilities. They facilitate the management, search, discovery, configuration, security, and remix of GIS data layers and services. Today, portals of different organizations can collaborate as hosts and guests, creating a “portal of portals” by using a distributed Web GIS pattern.
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, cloud GIS, such as ArcGIS Online, has penetrated organizations that have not used GIS before or been able to afford GIS on their own.
Mobile is becoming the pervasive Web GIS client platform
As we entered the post-PC era, mobile devices have surpassed desktops and notebooks as the primary platform for accessing online information. Mobile devices are a part of people’s life and work. “Mobile First” was one of the strategies of many industries, including the Web GIS industry. Vendors have given extra attention to mobile GIS. For example, Esri provides numerous mobile native apps and mobile-friendly browser apps to support people’s and organization’s need for mobile GIS. Mobile GIS is also associated with many frontiers in Web GIS, such as augmented reality (AR). AR can superimpose GIS data on top of a user’s camera views and thus can augment a user’s sense of reality. With the rapid advances in mobile GIS, the vision of using GIS for anything, anytime, anywhere, and by anyone is being realized faster than we can imagine.
Map visualization goes from 2D to 3D and virtual reality (VR)
With the increased client-side graphics processing power and the broader support of WebGL, Web GIS products such as ArcGIS Online and ArcGIS Enterprise can create and display thematic and photo-realistic 3D web scenes smoothly. Representing a big step from 2D online maps, 3D web scenes provide web users a more intuitive means to understand their data. 3D scenes are also important for indoor mapping, an ongoing trend in GIS. Even more intuitive than 3D, VR, such as ArcGIS 360 VR, allows users with certain visual wearables to immerse themselves into 3D city models by teleporting to static viewpoints and comparing different urban design scenarios. The immersive experience brings GIS data and geospatial understanding even closer to users.
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 networks and smart cities. This massive amount of data presents challenges in real-time intake, processing, analysis, visualization, and storage. ArcGIS GeoEvent Server and the ArcGIS Trinity project utilize cluster computing and can ingest thousands and millions of sensor readings per second, process them, and store them in real time. Such products and research allow Web GIS to meet the requirements of the Sensor Web interface and the Internet of Things (IoT).
Web GIS becomes smarter and more intelligent
Map visualization is the first step toward data analysis. Online mapping becomes smart today. ArcGIS Smart Mapping can analyze the data automatically and suggest the best mapping style and the best defaults. This can help users, experts or novice, create beautiful and informative maps quickly. Web GIS goes far beyond mapping. ArcGIS GeoAnalytics Server can perform big data analysis using distributed computing, aggregate data in the context of both space and time, extrapolate new ideas from raw data, and bring superior intelligence to business decisions. More recently, Web GIS has started to use machine learning and artificial intelligence. For example, machine learning significantly improved the accuracy of online imagery classification. Artificial intelligence has been able to quickly identify the damaged locations from millions of facilities’ photos, and ensure the damaged facilities are repaired early.
Paths to building Web GIS applications
The tutorials in this book teach readers how to build Web GIS apps. The ArcGIS suite of Web GIS products offers many paths to this goal.
ArcGIS offers many ways to build web applications. The green lines in the figure highlight the technology presented in this chapter.
The previous figure presents the three basic tiers in Web GIS architecture and the generic workflow to build Web GIS apps:
The data tier (on the left side of the figure) contains formats that range from simple CSVs managed with Microsoft Excel to sophisticated geodatabases managed with enterprise databases. This allows you to create map documents, toolboxes, and 3D scenes in ArcGIS® Desktop software, especially ArcGIS® Pro.
In the middle tier of the figure, you can publish desktop resources to ArcGIS Online or ArcGIS Enterprise as several types of web layers and services. You can then add these layers and services to 2D web maps and 3D web scenes.
Options for the presentation (or client) tier on the right side of the figure are essential apps. Apps range from ready-to-use ones that can be configured without programming to custom ones that use various web application programming interfaces (APIs) or software development kits (SDKs) to
