A little over a year ago a group was added to ArcGIS Online with some beta content. The group is called Landscape Layers, and it contained about 70 layers that followed a new model of content publishing. Since then the number of layers has more than doubled and the content is no longer beta--these have become fully supported esri-authored content layers.
You might wonder why these layers were new and continue to be special? There are two big reasons:
- The content in these layers supports landscape analysis, which underpins a big part of land use planning. Read the group's description to learn more.
- Unlike previous content, which only supported mapping, the landscape layers support both mapping and analysis. That means many of these layers could be used as inputs in geoprocessing tools and models in ArcGIS Desktop or online via REST and the various ArcGIS APIs.
The significance of additionally supporting analysis is, in my opinion, huge. It means not having to download data first. It means not fixing the data to make it GIS-ready after you've downloaded it. In many cases, but perhaps most obviously with the Soils layers, you do not have to learn how the data was published before you can make it GIS-ready, or use it. This makes ArcGIS and your work more efficient by leveraging the Cloud.
That said, the technology for delivering these layers continues to be a work in progress. Today, image and feature services can be the basis for layers that support both mapping and anlaysis, however both have limitations with respect to how much data can be analyzed.
Image services are limited by the number of images and pixels that can be used. Feature services are limited with respect to the number of features that can be queried, and when the result is more than 1,000 features, performance is quite slow. Thus, we felt we could be ambitious in publishing the image services such that 24,000 x 24,000 pixels could be analyzed. The descriptions for each of the landscape layers contains information about what that specifically means given the resolution of the data behind the layer.
For vector data, we chose to deliver dynamic map services, rather than feature services. This was for two reasons: 1) drawing performance, 2) avoiding the query performance issues mentioned above while the development team is working to address them. To support analysis of that vector data we created a geoprocessing service (Extract Landscape Source Data) that works in ArcMap, allowing you to specify a study area extent that you digitize or that comes from an existing layer, which is sent to the service and the result is a ZIP file containing a geodatabase with the extracted data. See the description for details about how much data can be downloaded from each of the supported landscape vector datasets.
Last, and definitely very important to us, is your feedback. Use the comments in ArcGIS Online for layer-specific feedback.