Web GIS: What Kind of Data is Available?

The mission of every GIS organization is to perform specific functions within its jurisdiction. Each of these departments, groups, or agencies is committed to building key authoritative data layers to support its work. This work includes the compilation of foundational data layers as well as standard basemap layers for their geographies and applications.
For such organizations—and they are myriad in local, regional, state, and national levels around the globe—this information has served as the basis for all of their comprehensive GIS applications. During the early days of GIS, the compilation of these data layers was one of the primary tasks of each organization. As this data was developed, GIS data developers were able to leverage their information resources in various kinds of GIS applications that extend their own work and help their constituents.

Designed for marine GIS applications, the Ocean basemap includes bathymetry, derived depths, and surface and subsurface feature names.
The result is that all these different agencies have created data that is considered, in legal terms, a system of record maintained to support their mandated domain. The pace of migrating this data into Web GIS is increasing, and we are now seeing much content coming online that fills in gaps for the entire world. The result is a continuous coverage of geographic information worldwide—the Web GIS of the world.


Image layers enable you to view recent, high-resolution imagery for most of the world; multi-spectral imagery of the planet updated daily; and near real-time imagery for parts of the world affected by major events, such as natural disasters.


Basemaps provide reference maps for the world and the context for your work. Built from the best available data from the ArcGIS community of reliable data providers, these maps are presented in multiple cartographic styles.

Demographics and Lifestyles

Demographics and Lifestyles maps—of the United States and more than 120 other countries—include recent information about total population, family size, household income, spending, and much more.
This map of Singapore emphasizes areas with the highest population density (more than 50,000 persons per square kilometer).

Boundaries and Places

Many places are logically defined by a boundary. Boundaries and Places map layers describe these areas at many levels of geography, including countries, administrative areas, postal codes, and more.


This category contains maps and layers that describe the systems that people use to move between places. It includes a variety of global, national, and local maps on various topics from infrastructure projects to rest areas. Some of these layers are dynamic, such as the live World Traffic map, which is updated every few minutes with data on traffic incidents and congestion.
This map shows the Tube routes and stations in London.

Earth Observations

Earth Observations maps and layers are collected from sensors on the ground and satellites in space. They describe our planet’s current conditions, from earthquakes and fires to severe weather and hurricanes, and they enable us to see changes over time.

Urban Systems

These layers depict data about human activity in the built world and its economic activities and include things like utility infrastructures, parcel boundaries, 3D cityscapes, housing, and employment statistics.
Areas that are within 10 minutes of a freeway exit are emphasized on this map to give an indication of how accessible neighborhoods are by highway.

Historical Maps

This collection includes scanned raster maps presented as both static map layers and dynamic image layers. These layers can be viewed individually as a basemap or displayed with a current basemap for comparison purposes.


This post is excerpted from the new book, The ArcGIS Book: 10 Big Ideas about Applying Geography to Your World. The twin goals of this book are to open your eyes to what is now possible with Web GIS, and then spur you into action by putting the technology and deep data resources in your hands. The book is available through and other booksellers, and is also available at for free.

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